KR100513753B1 - Paper-feeding apparatus of office machine - Google Patents

Abstract

The paper feeding device of the office equipment of the present invention includes at least one drive motor, at least one first drive roller located downstream of the paper feed path of the pickup roller, and at least one or more arranged to press the paper with a constant pressure against the first drive roller. The power of the drive motor is transmitted to the first drive roller when the second drive roller and the paper are picked up so that the first and second drive rollers are driven in the direction of picking up and transporting the paper, and the power of the drive motor is transferred during the paper transfer. And a drive roller power transmission device which is transferred to the second drive roller to be driven in the direction in which the first and second drive rollers convey the paper. The paper feeding apparatus of the present invention can prevent skew feeding and paper jam, and improve the paper feeding accuracy of the feed roller by removing the braking force generated by the first and second drive rollers during paper feeding.

Description

Paper-feeding apparatus of office machine

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper feeder for office equipment such as copiers, printers, faxes, and the like, and more particularly, to eliminate skew feeding and paper jams by eliminating the drag force generated by the drive roller during line feeding. The present invention relates to a paper feeder for an office equipment that prevents and improves the paper feeding accuracy of a feed roller.

In general, office equipment such as copiers, printers, and fax machines include a paper feeder for feeding paper into an image forming unit.

As shown in FIG. 1, the paper feeding device 10 generally includes a paper cassette 20 on which paper P is loaded, and a frame 11 for receiving and detaching the paper cassette 20. And a pickup unit 30 which is provided with respect to the paper cassette 20 in the frame 11 and picks up the paper P loaded in the paper cassette 20, and also in the paper cassette 20 in the frame 11. And a conveying unit 40 which is installed in relation to and conveys the paper P picked up by the pick-up unit 30.

The pickup unit 30 supports the pickup roller assembly 31 through the pickup roller assembly 31 supported by the frame 11 and fixed to be able to pivot about the support shaft 35, and the power transmission gear train 37. It consists of a pickup roller drive motor 33 to drive.

The pickup roller assembly 31 picks up the paper P between the pickup roller 34 for picking up the paper P, a pickup roller gear (not shown) coaxially formed with the pickup roller 34 and the pickup roller 34. One-way power transmission unit (not shown), such as a spring clutch, which transmits rotational force only in a direction to rotate, and one end of the pickup roller shaft 34a so that the pickup roller 34 contacts the paper P at a predetermined pressure by its own weight. The other end has a housing 36 fixed to the support shaft 35 so as to be pivotable.

As shown in Fig. 2, the transfer unit 40 includes a drive and drive backup rollers 41 and 42 for transporting the paper P picked up by the pickup roller 34 of the pickup roller assembly 31, and the drive. And a feed roller (not shown) for transferring the paper P conveyed by the drive backup rollers 41 and 42 to an image forming unit (not shown).

The drive roller 41 is a drive roller gear train (not shown) having a one-way power transmission unit (not shown) such as a spring clutch so that the drive roller 41 is driven in the direction of picking up the paper while picking up the paper while idling during the paper feeding. It is configured to be connected to the pickup roller drive motor 33 through.

Looking at the operation of the conventional paper feeder 10 configured as described above are as follows.

First, when a printing command is given, the pickup roller 34 is rotated clockwise by the pickup roller assembly 31 of the pickup unit 30 connected to the pickup roller drive motor 33 through the power transmission gear train 37. do.

As a result, the paper P is picked up by the clockwise rotational force of the pickup roller 34 while being in contact with the pickup roller 34. At this time, the paper P is driven only by the frictional resistance of the friction buckle or dam 39 installed in the paper feed cassette 20 and the rotational force of the pickup roller 34. 41, 42).

Thereafter, the paper P is conveyed toward the feed roller and the feed backup roller by the drive roller 41 connected to the pickup roller drive motor 33 through the drive roller gear train.

Subsequently, when the paper P operates a paper sensor (not shown) located near the feed roller, the control unit (not shown) causes the paper P to be aligned by the nip between the feed roller and the feed backup roller. After a predetermined time has elapsed, the pickup roller drive motor 33 is stopped and the feed roller drive motor (not shown) is operated to stop the pickup roller 34 and drive the feed roller.

At this time, the pickup roller 34 and the drive roller 41 which are subjected to the clockwise rotational force by the paper P are idle by the one-way power transmission part of the pickup roller assembly 31 and the drive roller geartrain, respectively.

Thereafter, the paper P is continuously conveyed to the image forming portion by the feed roller, and discharged after completion of printing in the image forming portion.

However, in the conventional paper feeder 10, since the pickup roller assembly 31 and the drive roller geartrain each have a one-way power transmission unit, the feed roller is fed to the feed roller drive motor to pick up the paper P and then transport it. When driven by the feed roller, the feed roller is not only the weight of the pickup roller assembly 31 acting on the paper P and the pressure between the drive and the drive backup rollers 41, 42, but also the pickup roller assembly 31 and the drive roller. A braking force corresponding to the force for idling the pickup roller 34 and the drive roller 41 against the one-way power transmission of the gear train is received.

In this way, the braking force acting on the feed roller not only reduces the accuracy of the paper feed of the feed roller, but also causes the skew feeding or the paper jam in severe cases.

In addition, the conventional paper feeder 10 has a vector direction in which the pickup roller assembly 31 acts on the paper P by weight and the like, and the rotational force of the pickup roller 34 acting on the paper P when the paper is picked up. Since it is configured to act in the opposite direction, there was a problem in that the rotational compounding force of the pickup roller 34 is lowered at the time of paper pickup and the paper pickup efficiency of the pickup roller 34 is lowered.

When the paper pick-up efficiency of the pick-up roller 34 is lowered, a pick-up failure occurs such that the paper P is not picked up by the pick-up roller 34 or a jam occurs during paper pick-up.

The present invention has been made to solve the above problems, the object of the present invention is to improve the paper feed accuracy of the feed roller by eliminating the braking force generated by the drive roller during the paper transfer and to prevent skew feeding and paper jams To provide a paper feeder for the office equipment.

Another object of the present invention is to improve the paper pick-up efficiency of the pickup roller by rotating the pickup roller assembly so that the rotational force acting on the paper and the vector direction of the rotational force acting on the paper when the pickup roller acts in the same direction. To provide a paper feeder.

In order to achieve the above object, the present invention is a paper feeder of the office equipment including a pickup roller assembly having at least one pickup roller for picking up the paper, at least one drive motor, the paper feed path downstream of the pickup roller At least one first drive roller positioned in the at least one drive roller, the at least one second drive roller arranged to press the paper at a constant pressure against the first drive roller, and the power of the drive motor to transfer the power of the drive motor to the first drive roller when the paper is picked up. The first and second drive rollers are driven in the direction of picking up and transporting the paper, and when the paper is transported, the drive motor is transmitted to the second drive roller to drive the first and second drive rollers in the direction of transporting the paper. Feeding stations for office equipment, including drive roller power trains, preferably To provide

In a preferred embodiment, the drive roller power train has a first drive coaxially formed with the first drive roller on the first drive roller shaft in accordance with a rotational direction of the feed roller gear coaxially formed with the feed roller that feeds the paper to the feed roller shaft. And a swing gear portion connecting one of the roller gear and the feed roller gear and between the feed roller gear and the second drive roller gear coaxially formed with the second drive roller on the second drive roller shaft.

At this time, the feed roller gear is preferably connected to the motor shaft of the drive motor through a plurality of gears.

In addition, the swing gear portion may include a first swing idle gear arranged to engage with the first drive roller gear, a second swing idle gear arranged to engage with the second drive roller gear, and a feed roller gear arranged to engage with the feed roller gear. It is preferably composed of at least one swing gear arranged to selectively engage with one of the first and second swing idle gears according to the direction of rotation. The swing gear has a swing lever that hinges the swing gear to the frame for selectively engaging with one of the first and second swing idle gears in accordance with the rotational direction of the feed roller gear.

In addition, the drive roller power train is installed on the first drive roller shaft, and the power of the drive motor transmitted to the first drive roller gear through the swing gear and the first swing idle gear is picked up by the first drive roller at the time of paper pickup. While conveying to the second drive roller, the power of the drive motor transmitted to the first drive roller through the swing gear, the second swing idle gear, the second drive roller gear, and the second drive roller during the paper transfer is picked up. It further comprises a one-way power transmission for causing the first drive roller to idle in the direction of conveying the paper so as not to be transferred to the pickup drive gear of the assembly.

The one-way power transmission is wound to generate a sliding friction force between the roller hub of the first drive roller installed on the first drive roller shaft, the bushing hub of the bushing fixed to the first drive roller shaft, and the bushing hub and the roller hub. It is preferably composed of at least one spring clutch comprising a clutch spring.

The pickup roller assembly includes a pickup drive gear formed on a first drive roller shaft coaxially formed with the first drive roller and the first drive roller gear, a pickup roller gear coaxially formed with the pickup roller on the pickup roller shaft, and between the pickup drive gear and the pickup roller gear. And at least one pickup idle gear disposed at and transferring power of the drive motor from the pickup drive gear to the pickup roller gear. At this time, in order for the pickup roller assembly to act in the same direction as the vector direction of the force acting on the paper and the rotational force acting on the paper when picking up the paper, the first drive roller shaft is vertically extended from its center. It is preferable that the pick-up roller shaft is disposed downstream of the paper pick-up direction rather than the vertical surface.

The paper feeding apparatus of the present invention has a pickup roller assembly lifting portion for contacting or spaced between the pickup roller of the pickup roller assembly and the paper according to the rotational direction of the first drive roller shaft so that the pickup roller of the pickup roller assembly contacts the sheet during paper pickup. It includes more.

The pickup roller assembly lifting section is provided with an elastic spring mounted to the pickup roller shaft and both ends supported between the frame and the pickup roller assembly.

Optionally, the pick-up roller assembly lifter is installed with respect to the feed cassette and the pick-up roller assembly to be operated by the feed cassette for loading the paper, so that the pick-up roller of the pick-up roller assembly is pressed against the paper when the feed cassette is mounted or detached from the frame. Can be configured to contact or space apart.

In this case, the pickup roller assembly elevating portion has an elevating guide groove formed at the upper end of the sidewall of the paper cassette, an elevating shaft having a protruding guide supported so as to elevate by the elevating guide groove at one end thereof, and the elevating shaft having a raised guide. A link member fixed between the pick-up roller assembly and the other end of the lifting shaft to move the pick-up roller of the pick-up roller assembly into a lowered position in contact with the paper and a raised position away from the paper when rotated by the pick-up roller assembly. And a tension section that pulls the pickup roller assembly in the ascending direction to maintain the pickup roller in the raised position.

The link member is composed of a first link having one end fixed to the other end of the lifting shaft, and a second link having both ends supported on the other end of the first link and the pick-up roller assembly, respectively.

Preferably, the tension portion is composed of a tension spring fixed at one end to one of the second links of the pickup roller assembly and the link member and the other end fixed to the frame.

In addition, the paper feeding apparatus of the present invention further includes a second drive roller releasing portion that separates the second drive roller from the first drive roller when a paper jam occurs.

The second drive roller releasing part is rotatably supported at one end by the frame and the other end is pivotally supported by the second driver roller shaft, and the second driver roller is first drive roller after the paper jam is removed. And a return for returning the release lever to the engaged position for engaging at a constant pressure.

The return portion is composed of a resilient spring supported on a fixed shaft supported so as to be pivotable on a corresponding support of the frame and on both ends of the release lever and the frame.

Hereinafter, a paper feeding device of an office equipment according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

Referring to FIG. 3, a paper feeding device 100 of an office device of the present invention is schematically illustrated.

The paper feeding device 100 of the present invention is installed in the frame with respect to the paper feed cassette 120 on which paper is loaded, a frame (not shown) for receiving and detaching the paper feed cassette 120, and the paper feed cassette 120. And a pick-up unit 130 for picking up paper, and a transfer unit 140 installed in the frame and transferring the paper P picked up by the pick-up unit 130.

The paper feed cassette 120 is provided with a plurality of friction bucklers 128 at the leading end, that is, the left side of the drawing, for feeding paper P by sheet at the time of paper pick-up.

The pickup unit 130 is a pickup roller assembly 131 fixed to be rotatable about the first drive roller shaft 142a of the drive roller part 141 fixed to the frame so as to cooperate with the driving motor 155 to be described later. And a pickup roller of the pickup roller assembly 131 according to the rotation of the first drive roller shaft 142a to bring the pickup rollers 134 and 134 'of the pickup roller assembly 131 into contact with the paper P when the paper is picked up. 134, 134 ') is made up of the pickup roller assembly lifting unit 150 for contacting or spaced apart from the paper (P).

Pick-up roller assembly 131 is the first drive roller shaft 142a to be driven by two pickup rollers 134, 134 'fixed to the pickup roller shaft 134a and the drive motor 155 to pick up the paper P. Between the pickup drive gear 139 and the pickup roller gear 135 formed coaxially with the pickup rollers 134 and 134 'on the pickup roller shaft 134a, between the pickup drive gear 139 and the pickup roller gear 135. A first disposed and fixed to the first, second and third pick-up idle shafts 136a, 137a, 138a to transfer power of the drive motor 155 from the pick-up drive gear 139 to the pick-up roller gear 135, respectively. Receiving the second and third pickup idle gears 136, 137, 138, and the gears 135, 136, 137, 138, 139 and supporting the shafts 134a, 136a, 137a, 138a, 142a. It consists of a housing 133.

The first drive roller shaft 142a is rotated by the pickup roller assembly 131 by its own weight and the gear force of the first drive roller gear 143 which will be described later, and the rotational force acting on the paper P and the pickup roller at the time of picking up the paper. The paper direction P is different from that in which the vector directions of the rotational forces 134 and 134 'act on the paper P act in opposite directions in the same direction, that is, the conventional paper feeder 10 described with reference to FIG. In order to act in the pick-up direction, it is preferable that a vertical plane extending at the center thereof is disposed downstream of the paper pick-up direction than the vertical plane of the pickup roller shaft 134a.

Pick-up roller assembly lifting unit 150 is installed on the pick-up roller shaft 134a and both ends of the support protrusion (not shown) formed in the frame and the support protrusion 133a formed in the housing 133 of the pickup roller assembly 131. It is composed of a supported elastic spring.

The elastic spring of the pickup roller assembly lifting unit 150 is the first drive roller gear 143 when the first drive roller gear 143 receives a force to rotate clockwise by the driving force of the drive motor 155 when picking up the paper. The first drive roller shaft 142a in the lowered position (solid line in FIG. 3), which is compressed by the gear force of the pick-up roller assembly 131 and the pick-up roller 134 contacts the paper P at a constant pressure. The pick-up roller assembly 131 when the first drive roller gear 143 is not subjected to the driving force of the driving motor 155, and the pick-up roller 134 is spaced apart from the paper P (Fig. And a dashed line 3) to rotate and return about the first drive roller shaft 142a.

The transfer unit 140 may include a drive roller unit 141 for transferring the paper P picked up by the pickup roller assembly 131, and an image forming unit (not shown) for the paper P transferred by the drive roller unit 141. Feed roller unit 146 for conveying to the discharge roller unit 165, the discharge roller unit 165 for discharging the printed paper through the image forming unit to the outside, and the drive roller unit 141, the feed roller And a drive motor 155 for driving the portion 146 and the discharge roller portion 165.

As shown in Fig. 4, the drive roller portion 141 is rotatable to the first drive roller shaft 142a supported to be pivotable to the frame downstream of the paper feed path of the pickup rollers 134 and 134 '. Two supported first drive rollers 142 and 142 '(FIG. 4), and the paper P to the second drive roller shaft 144a to press the paper P at a constant pressure against the first drive rollers 142 and 142'. It consists of two fixed second drive rollers 144 and 144 '.

One end of each of the first and second drive roller shafts 142a and 144a includes first and second swing idle gears 162 and 163 of the swing gear portion 160 constituting the drive roller power transmission device described later. Engaging first and second drive roller gears 143 and 145 (shown in FIG. 3 only) are coaxially fixed with first and second drive rollers 142 and 142 '; 144 and 144', respectively.

The feed roller part 146 is a feed roller gear 148 formed on the feed roller shaft 147a so as to cooperate with the first and second power transmission gears 156 and 157 connected to the motor shaft 155a of the drive motor 155. , A friction roller that presses the paper P at a constant pressure against the feed roller 147 so as to feed the paper P, the feed roller 147 coaxially formed with the feed roller gear 148, and the paper roller P on the feed roller shaft 147a. It consists of 149.

The friction roller 149 includes a friction roller holder 158 supported on the frame to impart a constant pressing force to the friction roller 149 by an elastic spring (not shown).

When the paper is picked up between the drive roller unit 141 and the feed roller unit 146, the power of the drive motor 155 is applied to the first of the drive roller unit 141 by the feed roller gear 148 of the feed roller unit 146. Transfers to the drive roller gear 143 so that the first and second drive rollers 142, 142 '; 144, 144' are driven in the direction of picking up and transporting the paper P (solid arrow in FIG. 3) and At the time of conveyance, the power of the drive motor 155 is transmitted from the feed roller gear 148 of the feed roller unit 146 to the second drive roller gear 145 of the drive roller unit 141 to transfer the first and second drive rollers. Drive roller power transmission devices 160 (170, 170 ') are arranged so that the 142, 142'; 144, 144 'are driven in the direction in which the paper P is conveyed (dotted arrow in Fig. 3).

The drive roller power train 160 (170, 170 ') is connected to the drive motor 155 through the first and second power transmission gears 156, 157 and the motor shaft 155a to convey the paper P. The feed roller gear 148 and the first are disposed between the roller gear 148 and the first and second drive roller gears 143 and 145 of the drive roller part 141 and according to the rotation direction of the feed roller gear 148. A swing gear unit 160 is connected between the drive roller gear 143 or between the feed roller gear 148 and the second drive roller gear 145.

The swing gear portion 160 has a feed roller on the first and second swing idle gears 162 and 163 arranged to engage the first and second drive roller gears 143 and 145, respectively, and the feed roller shaft 147a. A swing gear disposed to engage with the feed roller gear 148 coaxially formed with 147 and selectively engage with the first or second idle gear 162 or 163 according to the rotational direction of the feed roller gear 148. It is preferable that it is comprised by 161.

The swing gear 161 is fixed so that the shaft 161a can be rotated to the other end of a swing lever (not shown), one end of which is hinged to the frame, according to the rotational direction of the feed roller gear 148. Or selectively engages with second swing idle gear 162, or 163. Although the swing lever has been described as being hinged to the frame and not shown in the drawings, the swing gear 161 swings toward the first and second swing idle gears 162 and 163 by a small force. The hinge axis is positioned on the line of symmetry between the first and second swing idle gears 162 and 163 so that it remains in a neutral position where it can be, so that it is intermediate between the first and second swing idle gears 162 and 163. Position vertically without contacting any of the first and second swing idler gears 162, 163, or tilted at an angle to contact one of the first and second swing idler gears 162, 163. It is obvious that the swing lever can be configured to be maintained. Therefore, when the feed roller gear 148 rotates, the swing lever constantly corresponds to the direction of rotation of the feed roller gear 148 by the gear force of the feed roller gear 148 acting on the swing gear 161. As a result, the swing gear 161 pivots about the hinge axis together with the swing lever to mesh with the corresponding first or second swing idle gear 162 or 163.

In more detail, the swing gear 161 rotates counterclockwise for paper pickup, as the feed roller gear 148 is shown by the solid arrow in FIG. 162 is engaged with the second swing idle gear 163 when the feed roller gear 148 is rotated clockwise for paper conveyance, as shown by the dashed arrows in FIG. 3.

When the paper is picked up, the power of the drive motor 155 transmitted to the first drive roller gear 143 through the swing gear 161 and the first swing idle gear 162 transfers the first drive rollers 142.142 '. To the second drive rollers 144, 144 ′ through the swing gear 161, the second swing idle gear 163, the second drive roller gear 145, and the second drive roller ( The first drive roller is prevented from transmitting power of the drive motor 155 transmitted to the first drive rollers 142 and 142 'to the pickup drive gear 139 of the pickup roller assembly 131 through 144 and 144'. In order to allow the 142 and 142 'to idle, the drive roller power train 160 (170, 170') is connected to the first drive roller shaft 142a of the drive roller portion 141, as shown in FIG. It further includes a one-way power transmission unit (170, 170 ') installed.

The one-way power transmission units 170 and 170 'may include roller hubs 171 and 171' protruding from the first drive rollers 142 and 142 'installed to be rotatable to the first drive roller shaft 142a, respectively. Sliding friction force is applied to the bushing hubs 173a and 173a 'of the bushings 173 and 173' fixed to the first drive roller shaft 142a, and the bushing hubs 173a and 173a 'and the roller hubs 171 and 171'. It consists of two spring clutches 170 and 170 'consisting of clutch springs 175 and 175' wound up to occur. Although not illustrated, the clutch springs 175 and 175 'are fitted into the notches of the bushing hubs 173a and 173a', and the other ends thereof span the notches of the roller hubs 171 and 171 '. As the roller hubs 171 and 171 'and the bushing hubs 173a and 173a' are rotated, the roller hubs 171 and 171 'are rotated in the winding direction and clamped or loosened in the opposite direction to the winding.

   The first drive roller gear 143 fixed to the first drive roller shaft 142a is unidirectionally, for example clockwise, by the swing gear 161 and the first swing idle gear 162 of the swing gear portion 160. As it rotates, the clutch springs 175 and 175 'of the spring clutches 170 and 170' are wound in the winding direction. As a result, the clutch springs 175, 175 'have a smaller inner diameter due to sliding friction with the rollers and bushing hubs 171, 171'; 173a, 173a 'and the rollers and bushing hubs 171, 171'; 173a, 173a '. ), The rotational force of the bushing hubs 173a and 173a 'is transmitted to the roller hubs 171 and 171' of the adjacent first drive rollers 142 and 142 '. Thus, the rotational force of the first drive roller gear 143 is transmitted to the second drive rollers 144, 144 ′ through the first drive rollers 142, 142 ′.

 On the contrary, the first drive rollers 142, 142 ′ may include the swing gear 161, the second swing idle gear 163, the second drive roller gear 145, and the second drive roller 144 of the swing gear unit 160. 144 ', the clutch springs 175, 175' are released in the opposite direction to the winding direction. As a result, the clutch springs 175, 175 'have an inner diameter that is enlarged by sliding friction with the rollers and bushing hubs 171, 171'; 173a, 173a 'and the roller and bushing hubs 171, 171'; 173a, 173a '. Spaced apart from the outer circumferential surface of the first drive rollers 142 and 142 '. Therefore, the rotational force of the first drive rollers 142, 142 ′ is not transmitted to the pickup drive gear 139 of the pickup roller assembly 131.

 It should be noted here that the one-way power transmission unit in the present embodiment has been described as being composed of the spring clutches 170 and 170 ', but it should be understood that the present invention is not limited to this and may also be configured as a one-way power transmission gear such as a latch gear. something to do.

The discharge roller unit 165 is a discharge roller 166 connected to the drive motor 155 through a discharge roller gear train (not shown), and a discharge roller 166 to discharge the paper P printed by the image forming unit. And a medium back up roller 165 arranged to pressurize at a constant pressure.

In addition, the paper feeding device 100 of the present invention further includes a second drive roller releasing unit 180 that separates the second drive rollers 144 and 144 'from the first drive rollers 142 and 142' when a paper jam occurs. Include.

The second drive roller releasing unit 180 may include a release position (dotted line in FIG. 3) and a first drive roller (a dotted line) in which the second driver rollers 144 and 144 'are spaced apart from the first drive rollers 142 and 142'. 142, 142 'and one end portion 181a is rotatably supported in the frame and the other end portion 181b is rotatable between the second driver rollers 144, 144' so as to move between the engagement position (solid line in Fig. 3). And a release lever 181 for rotatably supporting the second driver roller shaft 144a having formed thereon, and a return unit 183 for returning the release lever 181 to the engaged position after the paper jam is removed. .

The return part 183 is supported by a fixed shaft 184 which is rotatably supported by a corresponding support part (not shown) of the frame, and both ends thereof are fixed projections 185 and the fixing projections of the frame, respectively. It consists of an elastic spring supported by (not shown).

The elastic spring has an elastic force that presses the second driver rollers 144, 144 ′ at a constant pressure against the first drive rollers 142, 142 ′.

Referring to Figures 3 and 4 the operation of the paper feeder 100 of the office equipment of the present invention configured as described above are as follows.

First, when a printing command is issued after the paper feed cassette 120 is mounted on the inner frame, as shown in FIG. 3, the drive motor 155 moves in one direction, for example, clockwise (for picking up the paper P). 3, the feed roller gear 148 connected to the shaft 155a of the drive motor 155 through the first and second power transmission gears 156 and 157 is counterclockwise. Is rotated.

As the feed roller gear 148 rotates in the counterclockwise direction, the swing gear 161 is swinged by the swing lever to be engaged with the first swing idle gear 162, and thus with the first swing idle gear 162. The interlocking first drive roller gear 143 is rotated clockwise.

As the first drive roller gear 143 rotates clockwise, the first drive rollers 142, 142 ′ coaxially formed with the first drive roller gear 143 in the first drive roller shaft 142a also have a one-way power transmission. It rotates in the clockwise direction through the negative spring clutch (170, 170 ').

At this time, since the bushing hubs 173a and 173a 'of the spring clutches 170 and 170' rotate in the winding directions of the clutch springs 175 and 175 ', the clutch springs 175 and 175' are formed of a roller and a bushing hub ( 171, 171 '; 173a, 173a', the inner diameter is reduced by sliding friction with the roller and the bushing hub (171, 171 '; 173a, 173a') close to the outer peripheral surface, the bushing hub (173a, 173a ') side The rotational force of is transmitted to the roller hubs 171 and 171 'of the adjacent first drive rollers 142 and 142'.

As such, the second drive rollers 144 and 144 'which are in constant contact with the first drive rollers 142 and 142' which rotate in the clockwise direction are rotated in the counterclockwise direction.

In addition, as the first drive roller gear 143 rotates in the clockwise direction, the pickup roller assembly 131 may move up and down of the pickup roller assembly lifting unit 150 by its own weight and the gear force of the first drive roller gear 143. The pick-up rollers 134, 134 'are brought into contact with the paper P at a constant pressure in an elevated position (dotted line in Fig. 3) spaced apart from the paper P against the elastic spring. 3, the pickup drive gear 139 coaxially formed with the first drive roller gear 143 in the first drive roller shaft 142a is rotated clockwise.

Accordingly, the pickup roller gear 135 in the pickup roller gear 135 and the pickup roller shaft 134a which are connected to the pickup drive gear 139 through the first, second, and third idle gears 136, 137, and 138. And the pick-up rollers 134 and 134 'coaxially formed are rotated in the clockwise direction, and as a result, the paper P is picked up by the rotational force of the pick-up rollers 134 and 134' while being in contact with the pick-up rollers 134 and 134 '. do.

At this time, the paper P is the first and second only the paper P located at the top due to the frictional resistance of the friction buckle 128 provided in the paper feed cassette 120 and the rotational force of the pickup rollers 134 and 134 '. It is conveyed toward the drive rollers 142, 142 '; 144, 144'.

At this time, the pickup roller assembly 131 is rotated by its own weight and the gear force of the first drive roller gear 143 to act on the paper P and the pickup rollers 134 and 134 'when picking up the paper. Since the vector direction of the rotational force acting on the paper P acts in the same direction, that is, in the direction of picking up the paper P, the paper pick-up efficiency of the pickup rollers 134, 134 'is improved.

The paper P conveyed to the first and second drive rollers 142 and 142 '; 144 and 144' has the first and second drive rollers 142, 142 '; 144 and 144' clockwise and clockwise, respectively. Since it rotates in the opposite direction, that is, in the same direction as the direction of picking up the paper P, it is conveyed toward the feed roller 147 and the friction roller 149 without receiving a special braking force.

When the paper P reaches near the feed roller 147 and operates a paper sensor (not shown) installed near the feed roller 147, the controller (not shown) causes the paper P to feed the feed roller ( After a predetermined time elapses when the tip is aligned by the nip between the 147 and the friction roller 149, to stop the pickup rollers 134 and 134 'and drive the feed roller 147 and the discharge roller 166, The motor 155 is driven in the opposite direction, that is, counterclockwise (dashed arrow in FIG. 3).

As the drive motor 155 rotates in the counterclockwise direction, the feed roller gear 148 connected to the shaft 155a of the drive motor 155 through the first and second power transmission gears 156 and 157 is a friction roller. 149 is rotated clockwise to convey the paper P together.

As the feed roller gear 148 rotates in the clockwise direction, the swing gear 161 is swinged by the swing lever to be engaged with the second swing idle gear 163, and as a result, is engaged with the second swing idle gear 163. The second drive roller gear 145 is rotated counterclockwise.

As the second drive roller gear 145 rotates counterclockwise, the second drive rollers 144, 144 ′ coaxially formed with the second drive roller gear 145 on the second drive roller shaft 144a also counterclockwise. Direction, so that the first drive rollers 142, 142 'which are in constant contact with the second drive rollers 144, 144' are rotated clockwise.

At this time, the roller hubs 171, 171 ′ of the spring clutches 170, 170 ′ have a winding direction of the clutch springs 175, 175 ′ as the first drive rollers 142, 142 ′ rotate clockwise. It will rotate in the opposite direction. As a result, the clutch springs 175, 175 'have an inner diameter that is enlarged by sliding friction with the rollers and bushing hubs 171, 171'; 173a, 173a 'and the roller and bushing hubs 171, 171'; 173a, 173a '. Spaced apart from the outer circumferential surface of the first drive rollers 142 and 142 '.

As the first drive rollers 142 and 142 'are idling, the first drive roller gear 143 and the pickup drive gear 139 are not driven by the driving motor 155, and as a result, the pickup roller assembly 131 ) Is moved back to the lifted position (dashed line in FIG. 3) by the elastic spring of the pickup roller assembly lifting unit 150.

Therefore, the paper P conveyed by the feed roller 147 and the friction roller 149 is transferred to the first and second drive rollers 142, 142 '; 144, 144' and the pickup rollers 134, 134 '. By this, it is moved to the image forming unit without any interference, and as a result, the paper feeding accuracy of the feed roller 147 is improved, and skew feeding or paper jam is prevented.

Thereafter, the paper P is discharged by the discharge roller 146 and the discharge backup roller 167 connected to the drive motor 155 through the discharge roller gear train after completion of printing in the image forming unit.

5 to 6B, there is illustrated a variation 150 ′ of the pickup roller assembly elevating unit of the sheet feeding apparatus 100 of the present invention.

The pickup roller assembly lifting unit 150 'is provided with respect to the paper cassette 120 and the pickup roller assembly 131 so as to be operated by the paper cassette 120, and the paper cassette 120 for loading paper P is provided. When mounted to or detached from the frame, the pickup rollers 134 and 134 'of the pickup roller assembly 131 are operated to contact or space the paper P at a predetermined pressure.

The pickup roller assembly elevating unit 150 ′ is rotatable to the frame such that the elevating guide groove 125 formed at the upper end of the side wall 123 of the paper cassette 120 and the elevating guide groove 125 at one end thereof. Lifting shaft 151 having supported projection guide 153, pick-up rollers 134, 134 'of pickup roller assembly 131 when the lifting shaft 151 is rotated by the projection guide 153, the paper (P). ) Between the other end of the elevating shaft 151 and the housing 133 of the pickup roller assembly 131 to move to the lowered position (FIG. 6B) in contact with the) and the raised position (FIG. 6A) to be spaced apart from the paper P. A fixed link member 154 and a tensioning portion 152 that pulls the pickup roller assembly 131 in the ascending direction to return the pickup rollers 134 and 134 'of the pickup roller assembly 131 to a raised position. do..

The lifting guide groove 125 of the paper feed cassette 120 and the protruding guide 153 of the lifting shaft 151 are respectively locked with the locking groove 125a and the locking protrusion so that the paper feed cassette 120 can be locked to each other when mounted on the frame. 153a is provided.

The link member 154 has a first link 154a having one end fixed to the other end of the lifting shaft 151 so that the pickup roller assembly 131 can be easily rotated with respect to the first drive roller shaft 142a. And a second link 154b having both ends of the first link 154a and both ends rotatably supported by the housing 133 of the pickup roller assembly 131, respectively.

One end of the tension portion 152 is fixed to the fixing protrusion 133b of the housing 133 of the pickup roller assembly 131, and the other end is composed of a tension spring fixed to a fixing protrusion (not shown) formed in the frame. Optionally, the tension spring of tension portion 152 may be configured to be secured between frame and second link 154b of link member 154.

Referring to the operation of the pickup roller assembly lifting unit 150 'configured as described above are as follows.

As shown in Fig. 6A, assuming that the paper cassette 120 is not mounted, first, the paper cassette 120 on which the paper P is mounted is moved in the arrow direction A to be mounted on the frame.

At this time, the lifting shaft 151 is rotated in the clockwise direction by the protruding guide 153 which is guided while ascending along the lifting guide groove 125 of the paper feed cassette 120.

Therefore, the first link 154a connected to the lifting shaft 151 rotates clockwise around the lifting shaft 151 to pull down the second link 154b, and thus the second link 154b The housing 133 of the hinged pickup roller assembly 131 is lowered against the tension spring of the tension portion 152.

As such, when the paper feed cassette 120 is mounted to the frame and the locking protrusion 153a of the protruding guide 153 is completely inserted into the locking groove 125a of the elevation guide groove 125, the pickup rollers 134 and 134 'are provided. As shown in Fig. 6B, is positioned at the falling position in contact with the paper (P).

Next, the case where the paper feeding cassette 120 is detached and described will be described. First, the paper feeding cassette 120 is moved in the arrow direction B as shown in FIG. 6B in order to be detached from the frame.

At this time, the protruding guide 153 which has rotated the elevating shaft 151 clockwise against the elastic force of the tension spring of the tensioning section 152 is removed from the frame along with the paper feed cassette 120. ), And the lifting shaft 151 is rotated in the counterclockwise direction by the pulling force of the tension spring of the tension portion 152.

As a result, the housing 133 and the second link 154b of the pickup roller assembly 131 are pulled up by the tension spring and raised upward.

As the housing 133 of the pickup roller assembly 131 ascends, the pickup rollers 134 and 134 'are moved to a rising position spaced apart from the paper P, as shown in Fig. 6A.

As described above, the paper feeder of the office equipment of the present invention to remove the braking force generated by the drive roller during the paper transport to improve the paper feed accuracy of the feed roller, and provide the effect of preventing skew feeding and paper jams do.

In addition, the paper feeding apparatus of the present invention is characterized in that the pickup roller assembly is rotated so that its own weight and the gear force of the pickup drive gear, or the rotational force acting on the paper by the pickup roller assembly elevating unit, and the rotational force acting on the paper during pickup of the paper The vector direction acts in the same direction to improve the paper pick-up efficiency of the pickup roller.

In the above, specific preferred embodiments of the present invention have been illustrated and described. However, the present invention is not limited to the above-described embodiments, and any person having ordinary skill in the art to which the present invention pertains without departing from the spirit and spirit of the present invention as claimed in the claims may have various modifications and Modifications may be made.

1 is a perspective view of a paper feeding device of a conventional office equipment.

FIG. 2 is a side view of the paper feeding device shown in FIG. 1. FIG.

Figure 3 is a schematic side view of a paper feeding device of an office equipment according to the present invention.

4 is a partial plan view illustrating a connection relationship between the pickup roller assembly, the one-way power transmission unit, and the drive roller unit of the paper feeding device shown in FIG. 3;

5 is a perspective view illustrating a modification of the pickup roller assembly lifting unit of the paper feeding device shown in FIG. 3.

6A and 6B are side views illustrating the operation of the pickup roller assembly lifting unit shown in Fig. 5;

* Description of the symbols for the main parts of the drawings *

10, 100: paper feeder 20, 120: paper feed cassette

30, 130: pickup unit 31, 131: pickup roller assembly

34, 134, 134 ': pickup roller 34a, 134a: pickup roller shaft

40, 140: transfer unit 41, 142, 142 ', 144, 144': drive roller

125: lifting guide groove 135: pickup roller gear

136, 137, 138: Pickup idle gear 139: Pickup drive gear

141: drive roller parts 142a and 144a: drive roller shaft

143 and 145: drive roller gear 146: feed roller portion

147: feed roller 147a: feed roller shaft

148: feed roller gear 149: friction roller

150, 150 ': Pickup roller assembly lift

151: lifting shaft 152: tension portion

153: protrusion guide 154: link member

160: swing gear 161: swing gear

162, 163: swing idle gear 166: discharge roller

170, 170 ': spring clutch 171, 171', 173a, 173a: hub

175, 175 ': clutch spring 180: drive roller releasing part

181: release lever 183: return portion

Claims (17)

In the paper feeder of the office equipment comprising a pickup roller assembly having at least one pickup roller for picking up paper, At least one drive motor; At least one first drive roller located downstream of the paper transport path of the pickup roller; At least one second drive roller arranged to press paper at a predetermined pressure against the first drive roller; And When the paper is picked up, the power of the driving motor is transmitted to the first drive roller so that the first and second drive rollers are driven in the direction of picking up and transporting the paper. And a drive roller power transmission device which is transferred to the drive rollers so that the first and second drive rollers are driven in the direction of conveying the paper. According to claim 1, wherein the drive roller power transmission device is formed coaxially with the first drive roller on the first drive roller shaft in accordance with the rotational direction of the feed roller gear coaxially formed with the feed roller for feeding the paper to the feed roller shaft And a swing gear portion connecting one of the first drive roller gear and the feed roller gear and the second drive roller gear coaxially formed with the second drive roller to the second drive roller shaft and the feed roller gear. Paper feeder for office equipment. The paper feeder of claim 2, wherein the feed roller gear is connected to the motor shaft of the drive motor through a plurality of gears. The method of claim 3, wherein the swing gear portion, A first swing idle gear disposed to engage the first drive roller gear; A second swing idle gear disposed to engage with the second drive roller gear; And And at least one swing gear disposed to engage the feed roller gear and selectively engaged with one of the first and second swing idle gears in accordance with the rotational direction of the feed roller gear. Feeder. 5. The swing gear of claim 4, wherein the swing gear comprises a swing lever hingedly fixed to the frame for selectively engaging one of the first and second swing idle gears in accordance with a rotational direction of the feed roller gear. Paper feeder for office equipment. 5. The drive according to claim 4, wherein the drive roller power train is installed on the first drive roller shaft, and the drive transmitted to the first drive roller gear through the swing gear and the first swing idle gear when picking up paper. The power of the motor is transmitted to the second drive roller through the first drive roller, and when the paper is conveyed, the swing gear, the second swing idle gear, the second drive roller gear, and the second drive roller are It characterized in that it further comprises a one-way power transmission unit so that the power of the drive motor transmitted to the first drive roller is not transmitted to the pickup roller assembly so that the first drive roller idles in the direction of conveying the paper. Paper feeder for office equipment. The method of claim 6, wherein the one-way power transmission unit, A roller hub of the first drive roller rotatably mounted to the first drive roller shaft; A bushing hub of the bushing fixed to the first drive roller shaft; And And at least one spring clutch including a clutch spring wound to generate sliding friction on the bushing hub and the roller hub. The method of claim 1, The pickup roller assembly may include a pickup drive gear formed on a first drive roller shaft coaxially formed with the first drive roller and the first drive roller gear, a pickup roller gear coaxially formed with the pickup roller on the pickup roller shaft, and the pickup drive gear. At least one pickup idle gear disposed between the pickup roller gears and transmitting power of the drive motor from the pickup drive gear to the pickup roller gears; And the first drive roller shaft has a vertical plane extending vertically from the center thereof on a downstream side of the pickup roller shaft rather than a vertical plane of the pickup roller shaft. 9. The method of claim 8, wherein the pick-up roller of the pick-up roller assembly in contact with or spaced in the paper according to the rotational direction of the first drive roller shaft to contact the pick-up roller of the pick-up roller assembly in contact with the paper during paper pick-up The paper feeder of the office equipment further comprising a pickup roller assembly lift. 10. The paper feeder of claim 9, wherein the pickup roller assembly elevating unit includes an elastic spring installed at the pickup roller shaft and both ends of which are supported between the frame and the pickup roller assembly. 10. The apparatus according to claim 8, wherein the feed cassette and the pickup roller assembly are installed so as to be operated by a paper cassette for loading paper, and the paper is picked up by the pick roller of the pickup roller assembly when the paper cassette is mounted or detached from the frame. The paper feeder of the office equipment, characterized in that it further comprises a pickup roller assembly lifting unit for contacting or spaced apart at a predetermined pressure. The method of claim 11, wherein the pickup roller assembly lifting unit, A lifting guide groove formed at an upper end of the sidewall of the paper feed cassette, An elevating shaft having a protruding guide supported at one end so as to be rotatable to the frame such that the elevating guide groove is elevated; When the lifting shaft rotates by the protruding guide, the other end of the lifting shaft and the pickup roller assembly to move the pickup roller of the pickup roller assembly to the lowered position contacting the paper and the elevated position away from the paper. A link member fixed to the, and And a tension unit for pulling the pickup roller assembly in an ascending direction to maintain the pickup roller of the pickup roller assembly in an elevated position. The method of claim 12, wherein the link member, A first link having one end fixed to the other end of the lifting shaft; And And a second link having each other end of the first link and both ends supported to be rotatable to the pick-up roller assembly.      13. The paper feeder of claim 12, wherein the tension portion comprises a tension spring fixed at one end to one of the link members and at one of the pickup roller assemblies and at the other end fixed to the frame. The paper feeder of claim 1, further comprising a second drive roller releasing portion spaced apart from the first drive roller when the paper jam occurs. The method of claim 15, wherein the second drive roller releasing portion, A release lever rotatably supported at one end to the frame and rotatably supported at the other end to the second driver roller shaft; And And a return unit for returning the release lever to the engaged position for engaging the second driver roller with the first drive roller at a constant pressure after the paper jam is removed. 17. The office device according to claim 16, wherein the return unit includes an elastic spring supported on a fixed shaft supported so as to be pivotable to a corresponding support of the frame, and both ends of which are supported by the release lever and the frame. Feeder.