JP2004051377A - Sheet material carrying device, recorder and recording system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of a duplicate feed while lengthening the service life of a roller. <P>SOLUTION: Retard levers 7 and 8 support a retard roller shaft 6, and freely rotate with the rotational axis 9 as the center, and press a retard roller 5 to a carrier roller 4. Retard pressure contact springs 12 and 13 are hooked on a spring hooking part of the retard levers 7 and 8 and spring hooks 14 and 15 of a slider 16. When a limiter gear 11 of a torque limiter 10 rotates, fastening force to an inner ring 30 by a stepped spring 33 changes, and rotational load torque of the retard roller 5 is changed. A motor 25 rotates the limiter gear 11, and vertically moves the slider 16, and thus, the rotational load torque of the retard roller 5 is changed, and pressure contact force of the retard roller 5 to the carrier roller 4 is changed. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a sheet conveying apparatus that separates and conveys sheet materials stacked and held one by one, a recording apparatus that performs recording on a sheet material that is a recording medium, and a recording system that controls the recording apparatus. It is about.

Conventionally, a plurality of recording media are set in a paper feed tray or a paper cassette, and only one of the plurality of recording media is separated and conveyed to a recording unit in accordance with a recording command, and an inkjet recording process or an electrophotographic Depending on the process, an ink jet recording apparatus that performs recording, a laser beam printer, and the like have been widely used.

In addition, with the progress of the ink jet recording process and the electrophotographic process, it has become possible to output high quality images, which are only for photographs.

On the recording medium side, there are a wide variety of special types, such as those with an ink receiving layer on the surface of the medium to achieve vivid color reproduction and those with a gloss layer to give a glossy feeling, in order to achieve high image quality output. The medium has been commercialized.

On the other hand, so-called ordinary media, such as copy paper, which is mainly used for recording texts, are still widespread in quantity.

要求 As a result of the demand for convenience as a recording device, there are overwhelmingly many recording devices that support both special media and ordinary media.

As a separation mechanism that separates and feeds these various recording media one by one, the following are typical ones.

1) Claw separation 2) Slope separation 3) Friction separation 4) Retard separation In the claw separation of 1), the separation is performed by curving the edge of the medium and moving over the claw. In this case, a large conveying force is required for bending, and this is mainly used for separating a medium in the sense that it is not realistic.

In the slope separation in 2), the magnitude relationship between the resistance force when the medium passes through the climbing slope, the frictional force between the media and the medium conveyance force, is set in an advantageous manner for the separation. The separation is performed by Although this method can be widely applied from ordinary media to special media, since the resistance greatly changes depending on the thickness and rigidity of the medium, there is a surface where non-feeding or double feeding is likely to occur during paper feeding.

The friction separation of # 3) is a method of preventing double feeding using a member called a separation pad (friction pad) having a high coefficient of friction with a recording medium. This method relies on the frictional force between the separation pad and the medium in order to dam the medium and prevent double feeding, so it is difficult to select a separation pad that can handle a wide variety of media, and separation is also required depending on environmental conditions. Since the frictional force between the pad and the medium changes, the reliability of the separation is limited.

In the retard separation of 4), a driving roller for feeding the recording medium, a driven roller pressed against the driving roller with a constant load, and a rotational load torque are applied when the driven roller rotates in the recording medium feeding direction. And a torque limiter. In this method, the rotational load torque generated by the torque limiter contributes to dam the medium and prevent double feed. That is, when a plurality of media enters the pair of the drive roller and the driven roller, if the medium return force converted from the rotational load torque of the torque limiter is set to be larger than the frictional force between the media, The media are separated from each other without being passed as a bundle, and only one sheet is separated.

As an advantage of this method, since the medium return force can be controlled to be constant by the rotational load torque of the torque limiter, there is no difference in the resistance force at the time of separation, such as slope separation or friction separation, depending on the medium type. In addition, it is hardly affected by environmental conditions.

A conventional example of a retard-type sheet feeding / separating apparatus will be described with reference to FIG.

This paper feed / separation device conveys the medium 102 to an image forming unit (not shown). The paper feed / separation device 101 includes a pickup roller 105 that feeds the medium 102 of the uppermost layer one by one from a storage device 103 on which the medium 102 is loaded, and forms an image (not shown) on the medium 102 fed by the pickup roller 105. And a retard that is disposed opposite to the drive roller 106 and rotates in the opposite direction to the drive roller 106 to separate the fed medium 102 into a single medium when a plurality of media 102 are fed. The image forming apparatus includes a roller 107 and a transport roller pair 9 disposed in front of the image forming unit. Guides 111 and 112 are arranged in the recording medium passage area so as to guide the medium 102.

The drive roller 106 and the retard roller 107 are driven by a drive transmission device 113 shown in FIG. The drive transmission device 113 includes a drive roller shaft 115 that supports the drive roller 106, a retard roller shaft 116 that supports the retard roller 107, and a retard roller drive shaft 117 that is connected to the retard roller shaft 116. The retard roller shaft 116 is supported by a swingable support member (not shown) and can be brought into contact with and separated from the drive roller shaft 115 in parallel. A coupling 119 and a torque limiter 120 are disposed between the retard roller shaft 116 and the retard roller drive shaft 117. Further, a clutch 122 for transmitting a driving force transmitted from a driving source (not shown) via a driving belt 121 to the driving roller 115 is provided at an end of the driving roller 115. A retard driving belt 123 that transmits the driving force transmitted to the driving roller 115 to the retard roller driving shaft 117 is wound between the driving roller 115 and the retard roller driving shaft 117. The coupling 119 is provided to transmit the drive from the retard roller driving shaft 117 to the retard roller shaft 116 even when the retard roller 107 is displaced.

When the medium 102 is fed one by one in the sheet feeding direction (the direction b in FIGS. 8 and 9) by the drive transmission device 113, the retard roller 107 rotates the retard roller driving shaft 117 by the idle rotation of the torque limiter 120. It is driven by the drive roller 115 in the direction opposite to the drive rotation direction.

When a plurality of media 102 are fed, the frictional force between the plurality of media is smaller than the frictional force between the retard roller 107 and the media 102. Instead, the retard roller 107 rotates in the same direction as the rotational drive direction of the retard roller drive shaft 117. As a result, only the uppermost medium among the plural media 102 sent is separated.

Note that, as described above, it is not always necessary to transmit the drive to the retard roller 107, and the separation device can be configured with only the torque limiter 120.

Next, conditions for satisfying the sheet feeding / separation of the recording medium 2 in the sheet feeding / separating apparatus 101 having the above configuration will be described dynamically. The symbols used in the following description are defined as follows.
Symbol μ _1-2 : Coefficient of friction between the first and second sheets μ _2-3 : Coefficient of friction between the second and third sheets μ Back- _c : Back side of paper and retard roller (C) Friction coefficient μ- _a : Coefficient of friction between the front side of paper and paper feed roller (a) μ- _b : Coefficient of friction P between front side of paper and feed roller (b): Pressing force of retard roller N: Pressing force from pressure plate to paper feed roller _Tc : Rotating torque of retard roller (generated max torque)
r _c: a dynamic model diagram when only one radially Figure 10 of the retard roller medium has entered the separated portion, FIG. 11 shows a dynamic model diagram when two medium has entered the separated portions, respectively. In the figure, the recording surface (front surface) is the upper side, and the back surface is the lower side.

に お い て In FIG. 10, the following two conditional expressions can be set.

Conditions for transporting the first sheet:
μ Table _-b × P + μ table _{-a × N> T c / r} c + μ 1-2 × N
That P> T _c / (μ Table _{-b × r c) -N × (} μ table _{-a -μ 1-2)} / _μ Table _{-b ····} (1)
Conditions under which the retard roller (c) rotates without slipping:
μ back- _c × P> T _c / r _c
That _{P> T c / (r c} × μ back _-c) ········ (2)
In FIG. 11, the following separation conditions can be set.

Balance of forces on the second piece of paper:
_{μ 1-2 × P + μ 1-2 ×} N = μ 2-3 × N + R c ······· (3)
Conditions in which the retard roller (c) is stopped:
_{R c <T c / r c} ········ (4)
From the equations (3) and (4), the condition that the first sheet is separated from the second sheet:
_{μ 1-2 × P + μ 1-2 ×} N <μ 2-3 × N + T c / r c ······ (5)
In the expression (5), if μ _1-2 = μ _2-3 , the conditional expression is as follows.

Separation conditions:
_{μ 1-2 × P <T c /} r c
That is, P <T _c / (r _c × μ _1-2 ) (6)
FIG. 12 shows a graph of the above conditions (1), (2), and (6) using the pressing force P of the retard roller 7 and the twisting torque _Tc of the torque limiter 20 as parameters.

In the figure, the shaded area is the normal feeding area. From this figure, it can be seen that the normal feeding area becomes wider when the sheet feeding condition is set under the condition of increasing both the pressing force P of the retard roller and the rotating torque _Tc of the retard roller (upper right direction in the figure). I understand.

However, the conventional recording apparatus having retard separation has the following disadvantages.

First, as described above, it is better to set the sheet feeding conditions under the condition that both the pressing force P of the retard roller and the swinging torque _Tc of the retard roller are increased (upper right in FIG. 12). The transmission area becomes wider.

However, under such condition setting, since the surface wear of the retard roller due to the recording medium is easily promoted, there is a disadvantage that the retard roller does not wrap around in a short period of time and normal feeding becomes impossible.

Second, in order to avoid the first drawback, if the sheet feeding conditions are set under the condition that both the pressing force P of the retard roller and the twisting torque _Tc of the retard roller are reduced (the lower left direction in FIG. 12), No problem occurs when the coefficient of friction between each roller and the medium is significantly larger than the coefficient of friction between the mediums, but the difference between the coefficient of friction between each roller and the medium and the coefficient of friction between the mediums is very small. In the case of paper or the like, while the normal feeding area in FIG. 12 is originally narrower, a narrower area is used, and double feeding is likely to occur during feeding. In particular, in the case of an ink jet recording apparatus which needs to convey a variety of media, this adverse effect is remarkable.

(4) As described above, it is very difficult to set the paper feeding conditions for stably feeding all the media, and there is a disadvantage that the conditions must be set at the expense of any one of the media.

Accordingly, it is an object of the present invention to provide a sheet conveying device, a recording device, and a recording system that do not cause double feeding while extending the life of the roller.

In order to achieve the above object, according to a first aspect, a sheet material holding means for stacking and holding a plurality of sheet materials, a driving roller for feeding the sheet material, and a pressure roller pressed against the driving roller with a constant load. A driven roller having a driven roller and a driven roller and a driven roller that separates and transports the sheet material held by the sheet material holding means one by one in a sheet material feeding direction; A torque limiter having a load torque varying means for applying a rotational load torque when the roller rotates and varying the generated rotational load torque, and a sheet material conveying device for controlling the rotational load torque generated by the load torque variable means And operating means operable from outside.

シ ー ト The sheet conveying apparatus of the present invention configured as described above can change the rotational load torque so as to meet the optimum conveying condition that changes depending on the type of the sheet.

According to the second aspect of the present invention, the rotational load torque in a plurality of stages can be selected by the operating means, so that the rotational load torque can be selected according to conditions such as the type of sheet material.

According to the third aspect of the present invention, since a lever which can be moved to a plurality of positions is provided as the operating means, the rotational load torque can be selected according to conditions such as the type of sheet material.

In the fourth aspect, the torque limiter includes an inner ring shaft that forms a part of the shaft of the driven roller, a spring wound along the outer peripheral surface of the inner ring shaft, and a first spring end that fixes one end of the spring. A load torque having a fixing portion and a second spring end fixing portion for fixing the other end of the spring, wherein the second spring end fixing portion is also rotated by rotating itself about the inner ring shaft as a rotation center. Since the load torque changing means can be rotated by the operating means, the rotating load torque can be changed by changing the tightening force of the spring.

In the fifth invention, since the first actuator for applying a rotational force to the load torque varying means and the first drive transmitting means for transmitting the driving force of the first actuator to the load torque varying means are provided, the actuator is provided. , The rotational load torque can be changed.

In the sixth aspect, the apparatus has a load varying means for varying the pressure contact load between the driving roller and the driven roller, and the operating means controls the pressure contact load generated by the load varying means, so that the pressure varies according to the type of sheet material and the like. In addition to the rotational load torque, the press-contact load can be changed so as to meet the optimum transport condition.

According to the seventh aspect, since the combination of the rotational load torque and the press-contact load in a plurality of stages can be selected by the operation means, the rotational load torque can be selected according to the conditions such as the type of the recording medium.

In the eighth invention, since the load varying means has a pressure contact spring for pressing the drive roller and the driven roller against each other and a means for varying the load generated by the pressure contact spring, the type of the sheet material, etc. The rotational load torque and the press-contact load can be changed so as to meet the optimal transfer conditions that change with the above.

In the ninth aspect, since the second actuator for providing the driving force to the load varying means and the second drive transmitting means for transmitting the driving force of the second actuator to the load varying means are provided, each actuator is energized. , The rotational load torque and the pressure contact load can be changed.

In the tenth aspect, since the first actuator and the second actuator are shared, by energizing and driving this actuator, the rotational load torque and the press-contact load can be changed.

The sheet conveying device according to an eleventh aspect of the present invention includes a holding unit that holds a plurality of stacked sheets, a driving roller that conveys the sheet, and a resistance that applies resistance to the sheet conveyed by the driving roller. A driven roller that prevents the sheet that is not in contact with advancing, a torque limiter that applies a rotational load torque when the driven roller rotates in the sheet feeding direction, and a driven roller that presses the driven roller against the driving roller. And a control unit for changing at least one of the rotational load torque of the torque limiter and the urging force of the urging unit.

The sheet conveying apparatus of the present invention configured as described above can change at least one of the rotational load torque of the torque limiter and the urging force of the urging means so as to match the sheet conveying conditions.

In the twelfth aspect, the control means changes at least one of the rotational load torque of the torque limiter and the urging force of the urging means in accordance with the type of the sheet, so that the control means is optimized according to conditions such as the type of sheet material. It can be adapted to various transport conditions.

According to a thirteenth aspect of the present invention, there is provided a recording apparatus which includes an ink jet head for discharging ink and records recording information on a sheet material as a recording medium by a recording unit. There is provided a distance varying means for varying the distance between the surface facing the recording medium and the surface of the recording medium on which recording is performed, and the operating means controls the distance varying means.

The recording apparatus of the present invention having the above-described configuration can set the optimum rotational load torque, pressure contact load, and distance between the recording medium surface and the recording medium depending on the type of the recording medium.

A recording system according to a fourteenth aspect of the present invention is a recording system for controlling recording on a recording medium by the recording device of the present invention, wherein the host device transmits a recording command to the recording device, and the host device transmits the recording command to the recording device. Specifying means for specifying the type, transmitting means for transmitting the specified recording medium information to the recording device, and control means for controlling the rotational load torque generated by the load torque varying means according to the transmitted recording medium information. It is characterized by having.

(4) Since the recording system of the present invention is configured as described above, it is possible to set the rotational load torque according to the medium designation on the host.

In the fifteenth aspect, since the control means controls the pressure contact load by the load variable means, it is possible to set the rotational load torque and the pressure contact load according to the medium designation on the host.

According to a first aspect of the present invention, there is provided a sheet material holding means for stacking and holding a plurality of sheet materials, a driving roller for feeding the sheet material, and a driven roller which is pressed against and driven by the driving roller with a constant load. In a sheet material transporting apparatus that separates and transports the sheet material held by the sheet material holding means one by one by a driving roller and a driven roller, the rotation is performed when the driven roller rotates in the sheet material feeding direction. A torque limiter having a load torque varying means for applying a load torque and varying a generated rotational load torque, and an operation operable from outside the sheet material conveying apparatus for controlling the rotational load torque generated by the load torque variable means Means.

The sheet conveying apparatus of the present invention configured as described above can change the rotational load torque so as to match the optimum conveying condition that changes depending on the type of the sheet, and stably stabilizes various kinds of sheet. A sheet material conveying device capable of conveying the sheet material can be realized.

In the second invention, the rotational load torque in a plurality of stages can be selected by the operating means. Therefore, the rotational load torque can be selected according to the conditions such as the type of the sheet material, and a wide variety of rotational load torques can be selected. It is possible to realize a sheet conveying apparatus capable of stably conveying the sheet and having excellent operability.

In the third invention, since a lever which can be moved to a plurality of positions is provided as an operating means, a rotational load torque can be selected according to conditions such as a type of a sheet material, and various kinds of sheet materials can be stably formed. Thus, a sheet material conveying device which can be conveyed and has excellent operability can be realized at low cost.

In the fourth aspect, the torque limiter includes an inner ring shaft that forms a part of the shaft of the driven roller, a spring wound along the outer peripheral surface of the inner ring shaft, and a first spring end that fixes one end of the spring. A load torque having a fixing portion and a second spring end fixing portion for fixing the other end of the spring, wherein the second spring end fixing portion is also rotated by rotating itself about the inner ring shaft as a rotation center. Variable means, and the load torque variable means can be rotated by the operation means, so that the rotational load torque can be changed by changing the tightening force of the spring. A small-sized and low-cost sheet material transporting device capable of stably transporting a sheet and having excellent operability can be realized.

In the fifth invention, since the first actuator for applying a rotational force to the load torque varying means and the first drive transmitting means for transmitting the driving force of the first actuator to the load torque varying means are provided, the actuator is provided. By energizing and driving, the degree of freedom of the position where the load torque variable means is provided increases, and the load torque can be initialized in combination with a sensor that directly and indirectly detects the phase of the load torque variable means, The user forgets to restore the load torque setting, which reduces the risk of adversely affecting the sheet conveyance and impairing the durability of the device, and stably supplies a wide variety of highly reliable sheet materials. A sheet conveying apparatus capable of conveying the sheet can be realized.

In the sixth aspect, the apparatus has a load varying means for varying the pressure contact load between the driving roller and the driven roller, and the operating means controls the pressure contact load generated by the load varying means, so that the pressure varies according to the type of sheet material and the like. In addition to the rotational load torque, the pressure contact load can be changed to meet the optimal transport conditions, and a sheet transport device that can transport a wide variety of sheet materials stably is realized. it can.

In the seventh aspect, the combination of the rotational load torque and the pressing load in a plurality of stages can be selected by the operating means. Therefore, the rotational load torque can be selected according to the conditions such as the type of the recording medium. A sheet conveying device capable of stably conveying various sheet materials and having excellent operability can be realized.

In the eighth invention, since the load varying means has a pressure contact spring for pressing the drive roller and the driven roller against each other and a means for varying the load generated by the pressure contact spring, the type of the sheet material, etc. The rotating load torque and the press-contact load can be changed to meet the optimal transport conditions that change with a large number of sheet materials without using a large-scale electric torque limiter or load variable means. Thus, a small-sized and low-cost sheet material conveying device which can be conveyed with high operability and excellent in operability can be realized.

In the ninth aspect, since the second actuator for providing the driving force to the load varying means and the second drive transmitting means for transmitting the driving force of the second actuator to the load varying means are provided, each actuator is energized. By driving the motor, the rotational load torque and the pressure contact load can be changed, the degree of freedom of the position where the load torque varying means and the load variable means are provided is increased, and the phase of the load torque varying means or the load variable means is directly and directly changed. In combination with the sensor that detects indirectly, it is possible to initialize the load torque and the pressure load of the drive roller and the driven roller, and the user forgets to return to these settings, which adversely affects sheet material conveyance. Stable conveyance of a wide variety of highly reliable sheet materials, reducing the risk of impacting or impairing device durability Rukoto can be realized sheet conveying apparatus capable.

In the tenth aspect, since the first actuator and the second actuator are shared, a highly reliable sheet material transporting device capable of stably transporting various sheet materials is provided. It can be realized at low cost.

The sheet conveying device according to an eleventh aspect of the present invention includes a holding unit that holds a plurality of stacked sheets, a driving roller that conveys the sheet, and a resistance that applies resistance to the sheet conveyed by the driving roller. A driven roller that prevents the sheet that is not in contact with advancing, a torque limiter that applies a rotational load torque when the driven roller rotates in the sheet feeding direction, and a driven roller that presses the driven roller against the driving roller. And a control unit for changing at least one of the rotational load torque of the torque limiter and the urging force of the urging unit.

The sheet conveying apparatus of the present invention configured as described above can change at least one of the rotational load torque of the torque limiter and the urging force of the urging means so as to match the sheet conveying conditions.

In the twelfth aspect, the control means changes at least one of the rotational load torque of the torque limiter and the urging force of the urging means in accordance with the type of the sheet, so that the control means is optimized according to conditions such as the type of sheet material. It can be adapted to various transport conditions.

According to a thirteenth aspect of the present invention, there is provided a recording apparatus which includes an ink jet head for discharging ink and records recording information on a sheet material as a recording medium by a recording unit. It has a distance varying means for varying the distance between the surface facing the recording medium and the surface of the recording medium on which recording is being performed, and the operating means controls the distance varying means. Rotational load torque, pressure load, and distance from the surface of the recording medium can be set, eliminating the need for individual settings, enabling a wide variety of recording media to be fed stably, and excellent operability. Recording device can be realized.

A recording system according to a fourteenth aspect of the present invention is a recording system for controlling recording on a recording medium by the recording device of the present invention, wherein the host device transmits a recording command to the recording device, and the host device transmits the recording command to the recording device. Specifying means for specifying the type, transmitting means for transmitting the specified recording medium information to the recording device, and control means for controlling the rotational load torque generated by the load torque varying means according to the transmitted recording medium information. Because it has, it is possible to set the rotational load torque according to the medium specification on the host, and it is not necessary to individually set the paper feed conditions, so it is possible to feed various types of recording media stably And a recording apparatus with excellent operability can be realized.

In the fifteenth aspect, since the control means controls the pressure contact load by the load variable means, it is possible to set the rotational load torque and the pressure contact load according to the medium designation on the host. It is possible to realize a recording apparatus capable of stably feeding paper and having excellent operability.

As described above, according to the present invention, the pressure contact load between the driving roller and the driven roller and the rotational load torque of the driven roller can be changed in accordance with the sheet material that is the recording medium. And double feed can be prevented.

Next, embodiments of the present invention will be described with reference to the drawings.
(1st Embodiment)
FIG. 1 is an overall perspective view showing the recording apparatus of the present embodiment.

The paper feed cassette 2 for storing the paper 1 as a recording medium is held at a position shown in the drawing by support means (not shown), and about 150 sheets of paper 1 can be set in the paper feed cassette 2. . The paper feed roller 3 is rotated by a drive mechanism and a drive transmission mechanism (not shown) so as to feed the paper 1 in the direction a. A pressure plate (not shown) is present in the paper feed cassette 2, and pushes up the entire paper at the time of paper feed so that the uppermost paper 1 is brought into contact with the paper feed roller 3. After the contact, the paper feed roller 3 rotates, and the paper 1 is fed. The transport roller 4 is rotated in the same direction as the paper feed roller 3 by a drive mechanism and a drive transmission mechanism (not shown). Rubber is wound around the surface of the transport roller 4. The retard roller 5 for applying resistance to the sheet conveyed by the conveying roller 4 and for preventing the sheet 1 not in contact with the conveying roller 4 from advancing also has rubber wound around the surface. The retard roller shaft 6 is provided so as to extend in the width direction of the sheet 1. The retard levers 7 and 8 that support the left and right ends of the retard roller shaft 6 are configured to be rotatable about a rotation center shaft 9 supported by a side plate (not shown). The spring upper portions of the retard pressure contact springs 12 and 13 are hooked on spring hook portions of the retard levers 7 and 8, and the lower portions are hooked on spring hooks 14 and 15. The spring hooks 14 and 15 are provided integrally with the slider 16. The slider 16 has two slide portions 17 and 18. These slide portions 17 and 18 fit into the slide holes 20 and 21 of the base 19 and can move up and down linearly. Therefore, the entire slider 16 can move up and down. In the state of FIG. 1, these two springs are charged, and the retard levers 7, 8 receive a load in the clockwise direction. With this load, in the case of the present embodiment, the retard roller 5 is pressed against the transport roller 4 at 2.9N. In this state, the retard roller 5 is driven to rotate by the transport roller 4. The retard roller shaft 6 also rotates integrally with the retard roller 5. The torque limiter 10 has a retard roller shaft 6 inserted therein, and serves to apply a load torque of about 0.03 N · m when the retard roller 5 is driven to rotate by the transport roller 4.

リ The limiter gear 11 constituting the load torque varying means is a part of the torque limiter 10. The driving force from the motor gear 24 to the limiter gear 11 is transmitted to the limiter gear 11 via an idler gear 23 provided via a support plate (not shown) fixed to the base 19 and an idler gear 22 fixed to the retard lever 8. . The motor gear 24 is attached to a rotating shaft of a motor 25. Further, an extension shaft 26 is mounted coaxially with the rotation shaft of the motor 25 via a coupling (not shown), and a gear 27 having the same shape as the motor gear 24 is provided on the opposite side of the extension shaft 26. When the motor 25 is energized, both the motor gear 24 and the gear 27 rotate. The details of these gear connecting portions will be described below with reference to FIG.

FIG. 2 is a view of the retard lever 8 side, which is cut at a cutting plane that is located in the middle of the sheet width of FIG. 1 and is perpendicular to the sheet 1 side. As described above, the driving force of the motor 25 functioning as the first actuator motor is transmitted to the limiter gear 11 via the motor gear 24 and the idler gears 23 and 22 as the first drive transmission means. That is, when the motor 25 is energized, the limiter gear 11 can be rotated.

On the other hand, the motor gear 24 constitutes second drive transmission means by meshing with the rack portion 28 of the slider 16. When power is supplied to the motor 25 which also functions as the second actuator, the rack portion 28 and thus the entire slider 16 can move up and down. This rack portion is also provided as a rack portion 29 on the opposite side as shown in FIG.

ス ラ イ ダ As the slider 16 moves up and down by the rotation of the motor gear 24, the spring hooks 14 and 15 move up and down. For this reason, the charge amount of the retard pressure contact springs 12 and 13 changes, and it is possible to change the pressure contact force of the retard roller 5 with respect to the transport roller 4. That is, the recording apparatus of the present embodiment uses the retard pressure contact springs 12, 13 and the slider 16, which is means for varying the load generated by the retard pressure contact springs 12, 13, to apply the pressure contact load between the transport roller 4 and the retard roller 5. It has as a load variable means for changing.

Next, the internal configuration of the torque limiter 10 will be described with reference to the sectional view of the torque limiter in FIG.

に は The retard roller shaft 6 indicated by a two-dot chain line is inserted into the inner ring 30. The inner ring 30 and the retard roller shaft 6 are fixed in the rotation direction by a groove 31. By inserting a spring pin inserted into a hole provided on the retard roller shaft 6 (not shown) into the groove 31, the retard roller shaft 6 is rotated. And the inner race 30 are integrally rotated as an inner race axis. The inner ring 30 is pivotally supported by an outer case 32 fixed to the retard lever 8. A stepped spring 33 wrapped around the inner race 30 in the outer case 32 has its right end inserted and fixed in a spring end hole 36 which is a first spring end fixing portion provided in the outer case 32. The stepped spring 33 has a small-diameter portion 33a wound tightly around the inner ring 30 and a large-diameter portion 33b in which a gap is formed between the inner ring 30 and the small-diameter portion 33a. The above-described limiter gear 11 fits into the outer case 32 and also serves as a lid for preventing the stepped spring 30 from falling off. The limiter gear 11 is provided with a spring end hole 37 as a second spring end fixing portion, and the left end of the stepped spring 33 on the large diameter portion 33b side is inserted and fixed. Since the limiter gear 11 can rotate about the axis of the retard roller shaft 6, the spring end hole 37 also rotates. When the spring end hole 37 rotates, the large-diameter portion 33b of the stepped spring 33 is displaced and transmitted to the small-diameter portion 33a, and the tightening force on the inner ring 30 changes. For this reason, the rotational load torque of the inner ring 30 changes, and consequently, the rotational load torque of the retard roller 5 when the retard roller 5 rotates in the paper 1 feed direction changes.

With the above configuration, the pressing force of the retard roller 5 against the transport roller 4 and the rotational load torque of the retard roller 5 can be changed at the same time. The direction of the change is such that when the pressing force is increased, the rotational load torque is also increased. The reason is that, as can be seen from the graph of the dynamic relationship in FIG. 12, it is better to set the condition so that the pressing force of the retard roller 5 against the transport roller 4 and the rotational load torque of the retard roller 5 are both increased. This is because the feeding area becomes wider and stable feeding becomes possible.

FIG. 4 is a graph showing the mechanical relationship of plain paper, and FIG. 5 is a graph showing the mechanical relationship of glossy paper used for ink jet recording. In general, glossy paper for ink jet recording has an ink receiving layer on the surface, so the surface tends to absorb moisture and the papers tend to stick together. Therefore, the coefficient of friction between sheets becomes larger than that of plain paper. Also, the friction coefficient between the rubber on the surface of the feeding roller and the surface of the paper tends to be equal to or slightly smaller than that of plain paper. For this reason, comparing FIGS. 4 and 5, the normal feeding area of the glossy paper of FIG. 5 is smaller, and the occurrence rate of double feeding and non-feeding is higher. Therefore, when recording on glossy paper, the conditions should be changed in such a manner that both the pressure contact force on the transport roller 4 and the rotational load torque of the retard roller 5 are increased, so that the normal feed area is used as wide as possible. I understand.

However, in the case of plain paper, since the normal feeding region is wide as shown in FIG. 4, it is desirable to set the pressing force and the rotational load torque lower than those of glossy paper in consideration of the durability of the retard roller 5.

Specifically, it is set as follows.

Condition setting for plain paper: 1.8 N pressing force, 0.02 Nm rotational load torque
Condition setting for glossy paper: pressure contact force 3.1 N, rotational load torque 0.03 N · m
Actually, since errors occur due to component variations in both the press-contact force and the rotational load torque, the range is set in a plurality of steps with the above values as the center values as shown by the squares in FIGS.

The operation means for instructing the rotation amount to the motor 25 includes a sheet type selection button provided on a recording apparatus main body (not shown) or a selection from a display means such as a liquid crystal on the recording apparatus. Any means that can be directly selected is effective.

Also, regarding the combination of the pressing force and the rotational load torque to be selected, the number of combinations may be determined according to the type of paper that the recording device can handle and the characteristics of the paper, and all combinations corresponding to all types of paper are selected. There is no need to be able to. In the present embodiment, it is determined that two sheets can be normally fed for all sheets. In this case, if an optical sensor or the like (not shown) can determine which of the two positions the phase of the motor gear 24 is in, it is easy to switch between the two.

Hereinafter, the operation of selecting the pressing force and the rotational load torque will be described with reference to the flowchart of FIG.

First, the power is turned on in Step1. In Step 2, in order to set the pressure contact force and the rotational load torque for plain paper, the output of a sensor for detecting a gear phase (not shown) is checked and initialized. Specifically, the motor 25 is rotated forward or backward while monitoring the output of the sensor, and stopped when the sensor can confirm that the motor gear 24 has reached a predetermined phase. When the motor 25 is a pulse motor, the motor 25 is energized to maintain its phase. Alternatively, if the driving resistance of the gear train is large, the gear phase is maintained even if the motor is turned off without energization.

(4) Next, paper is selected in Step 3. In Step 4, it is determined whether or not the paper is plain paper. If the paper is plain paper, the paper is fed and recorded as it is in Step 6, and if the paper is glossy paper instead of plain paper, the motor 25 is energized and rotated by a predetermined amount in Step 5, and the pressure contact force and load Change the torque. In Step 7, it is determined whether or not the recording is completed. If the recording is not completed, the flow returns to Step 3 to select the paper, and the same flow is repeated.

In the present embodiment, the torque limiter using the tightening force of the spring is used as the torque limiter.However, an electromagnetic limiter that can vary the torque according to the magnitude of the electromagnetic force, or a frictional force when the sheets are pressed against each other is used. Anything that can change the rotational load torque, such as a slip limiter that can change the torque by changing the pressing force, can be used in the present invention.

可 変 The pressure contact force of the retard roller 5 with respect to the transport roller 4 can be changed by a compression spring, a torsion coil spring or the like in addition to a tension spring. It is also possible to vary the pressing force by means other than a spring, such as an electromagnetic force.

Further, in the above-described embodiment, both the pressure contact force of the retard roller 5 with respect to the transport roller 4 and the rotational load torque of the retard roller 5 are changed. However, the present invention is not limited to this, and only one of the variables can be changed depending on the condition setting. In some cases, stable and normal paper feeding can be realized. Further, in the present embodiment, the configuration in which the drive source for changing the contact force and the rotational load torque is generated by one motor 25 has been described as an example. However, the present invention is not limited to this. It may be changed.

In addition, in the case of an ink jet recording apparatus, a means such as a lever for varying the distance between the ink jet recording head and the surface of the medium according to the thickness of the sheet is often provided. If the pressure contact force and the rotational load torque are configured to be variable in conjunction with the distance varying means, it is possible to realize an apparatus which does not require individual settings, has excellent operability, and can perform stable paper feeding.
(Second embodiment)
FIG. 7 is an overall perspective view illustrating the recording apparatus of the present embodiment.

In FIG. 7, the description of the portions having the same functions as those of the first embodiment will be omitted, and the description will be focused on different points.

The lever 50, which protrudes outward from the exterior of the recording apparatus (not shown) and can move to a plurality of positions, that is, is rotatably provided, can position its rotational position at a plurality of positions at left and right positions of the apparatus. The idler gear 51 rotates according to the position of the lever 50. As in the first embodiment, both the pressure contact force of the retard roller 5 against the transport roller 4 and the rotational load torque of the retard roller 5 can be changed according to the phase of the idler gear 51, without using an actuator such as a motor. Stable paper feeding is possible for various media.
(Third embodiment)
A medium setting on a printer driver installed in a host represented by a personal computer is indispensable, for example, because it relates to the setting of the ink ejection amount and the printing mode of the inkjet printing apparatus.

Therefore, the information of the medium setting at this time is transmitted from a host (not shown) outside the recording apparatus to the recording apparatus by a transmitting unit (not shown), and the pressing force against the transport roller 4 and the rotational load of the retard roller 5 are correspondingly transmitted. If the torque is changed, it is not necessary to separately change the paper feed conditions separately from other settings such as the print mode, so that a printing system with good operability can be realized.

The present invention is not limited to the numerical values and the like in each of the embodiments described above.

FIG. 2 is a perspective view of the recording apparatus according to the first embodiment of the present invention. FIG. 2 is a view taken along a cutting plane perpendicular to the sheet surface, which is located in the middle of the sheet width of FIG. It is sectional drawing of a torque limiter. It is the figure which made the mechanical relationship of plain paper into a graph. It is the figure which made the mechanical relationship of glossy paper a graph. It is a flowchart explaining the selection operation of the pressing force and the rotational load torque. FIG. 9 is a perspective view of a recording apparatus according to a second embodiment of the present invention. FIG. 10 is a side view showing a conventional example of a retard type sheet feeding / separating device. It is a perspective view showing a conventional example of a drive transmission device. FIG. 9 is a mechanical model diagram when only one medium enters the separation unit. FIG. 8 is a mechanical model diagram when two media enter a separation unit. FIG. 5 is a graph in which a pressing force P of a retard roller and a twisting torque _Tc of a torque limiter are used as parameters.

Explanation of reference numerals

REFERENCE SIGNS LIST 1 paper 2 paper feed cassette 3 paper feed roller 4 transport roller 5 retard roller 6 retard roller shaft 7, 8 retard lever 9 rotation center axis 10 torque limiter 11 limiter gear 12, 13 retard press contact spring 14, 15 hook 16 slider 17, 18 slide Part 19 Base 20, 21 Slide hole 22, 23, 51 Idler gear 24 Motor gear 25 Motor 26 Extension shaft 27 Gear 28, 29 Rack part 30 Inner ring 31 Groove 32 Outer case 33 Stepped spring 33a Small diameter part 33b Large diameter part 36, 37 end Hole 50 lever

Claims (15)

A sheet material holding unit configured to hold a plurality of sheet materials in a stacked state, a driving roller that feeds the sheet material, and a driven roller that is pressed against and driven by the driving roller with a constant load, and holds the sheet material. In a sheet material transporting apparatus that transports the sheet material held by the means by separating the sheet material one by one with the driving roller and the driven roller,
A torque limiter having a load torque variable unit that applies a rotational load torque when the driven roller rotates in a sheet material feeding direction, and varies the generated rotational load torque.
Operating means for controlling the rotational load torque generated by the load torque varying means, the operating means being operable from outside the sheet material conveying apparatus. The sheet conveying apparatus according to claim 1, wherein the rotational load torque in a plurality of stages can be selected by the operation unit. シ ー ト The sheet conveying apparatus according to claim 2, wherein the operating means is a lever movable to a plurality of positions. An inner ring shaft that forms a part of the shaft of the driven roller, a spring wound along an outer peripheral surface of the inner ring shaft, and a first spring end fixing portion that fixes one end of the spring. The load having a second spring end fixing portion for fixing the other end of the spring, wherein the second spring end fixing portion is also rotated by rotating itself about the inner ring shaft as a rotation center. The sheet conveying apparatus according to any one of claims 1 to 3, further comprising a torque varying unit, wherein the load torque varying unit can be rotated by the operation unit. 5. The seat according to claim 4, further comprising a first actuator that applies a rotational force to the load torque varying unit, and a first drive transmission unit that transmits a driving force of the first actuator to the load torque varying unit. Material transfer device. The load roller according to any one of claims 1 to 5, further comprising a load varying unit configured to vary a pressing load between the driving roller and the driven roller, wherein the operating unit controls the pressing load generated by the load varying unit. The sheet material conveying device as described in the above. The sheet conveying apparatus according to claim 6, wherein a combination of the rotational load torque and the press-contact load in a plurality of stages can be selected by the operation means. 8. The sheet conveying apparatus according to claim 6, wherein the load changing unit includes a pressing spring that presses the driving roller and the driven roller against each other, and a unit that changes a load generated by the pressing spring. 9. . 9. The apparatus according to claim 6, further comprising a second actuator that applies a driving force to the load varying unit, and a second drive transmission unit that transmits the driving force of the second actuator to the load varying unit. 10. 4. The sheet material conveying device according to claim 1. The sheet conveying apparatus according to claim 9, wherein the first actuator and the second actuator are commonly used. Holding means for holding a plurality of stacked sheets;
A drive roller for conveying the sheet,
A driven roller that applies resistance to the sheet conveyed by the driving roller and prevents the sheet that is not in contact with the driving roller from advancing,
A torque limiter that applies a rotational load torque when the driven roller rotates in the sheet feeding direction,
Urging means for urging the driven roller to press against the driving roller;
A sheet conveying apparatus having a control unit for changing at least one of a rotational load torque of the torque limiter and an urging force of the urging unit. The sheet conveying apparatus according to claim 11, wherein the control unit changes at least one of a rotational load torque of the torque limiter and an urging force of the urging unit according to a type of the sheet. 13. A sheet conveying device according to claim 1, further comprising a recording device that includes an ink jet head for discharging ink and records recording information on a sheet material as a recording medium by a recording unit. Recording means for varying the distance between the surface facing the recording medium and the surface of the recording medium on which recording is performed, wherein the operating means controls the distance varying means. apparatus. 14. A recording system that controls recording on a recording medium by the recording device according to claim 13, wherein a host device that transmits a recording command to the recording device and a type of the recording medium can be specified on the host device. Designating means, transmitting means for transmitting the designated recording medium information to the recording device, and control means for controlling the rotational load torque generated by the load torque varying means according to the transmitted recording medium information. Recording system characterized by the following. The recording system according to claim 14, wherein the control unit controls the press-contact load by the load variable unit.

Images