KR101674518B1 - Sheet conveying apparatus, image reading apparatus and image forming apparatus - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention is directed to reducing the force required for maintaining the state in which the first roller for delivering the sheet contacts the sheet in the sheet conveying apparatus.
As a means for solving such a problem, when the user instructs the start of copying or the start of scanning, the motor rotates in the normal rotation direction, and the feed roller 112 rotates in the direction of arrow Rb2. Along with this, the support frame 156 rotates in the direction of the arrow Rb2, and the pickup roller 111 performs circular motion about the rotation axis 151 in the direction of the arrow Rc2. The projecting portion 161 of the hook member 160 is released from the groove portion 176 of the lock member 170 and moves to the position where the pickup roller 111 contacts the original.

Description

[0001] SHEET CONVEYING APPARATUS, IMAGE READING APPARATUS AND IMAGE FORMING APPARATUS [0002]

The present invention relates to a sheet conveying apparatus, an image reading apparatus, and an image forming apparatus.

Patent Document 1 discloses a structure in which the pickup roller and the feed roller are constituted by a single roller unit, the pickup roller is kept separated from the sheet by using one spring, and when the sheet is fed, the solenoid is turned on ), And the pickup roller is pressed against the paper by an action of a spring different from the self weight of the roller unit, and the paper is sent out.

Japanese Patent Application Laid-Open No. 5-4733

SUMMARY OF THE INVENTION An object of the present invention is to reduce the force required for the first roller for delivering a sheet to remain in contact with the sheet in the sheet conveying apparatus.

The sheet conveying apparatus described in claim 1 is provided with a first roller for delivering a sheet by rotation, a second roller for conveying (conveying) the sheet delivered by the first roller by rotation, A supporting member rotatably supported by the first roller and capable of rotating about the rotation axis of the second roller, holding means for holding the supporting member in a state in which the first roller is separated from the seat, A first transmission mechanism for transmitting the driving force generated by the driving means to the second roller to rotate the second roller, and a second transmission mechanism for transmitting the driving force transmitted to the second roller to the first roller, A second transmission mechanism for rotating the first roller in a direction common to the second roller; and control means for controlling the drive means, wherein when the sheet is transported, Rotating the first roller and the second roller in the direction of conveying the sheet and rotating the support member held by the holding means about the rotation axis of the second roller And a control means for bringing the first roller into contact with the sheet by rotating the first roller in a state of being held by the holding means by circular motion in a direction approaching the sheet.

The sheet conveying apparatus described in claim 2 is the sheet conveying apparatus according to claim 1, wherein when the control unit does not convey the sheet, the control unit controls the driving unit to rotate in the direction opposite to the case of conveying the sheet The support member is rotated about the rotation axis of the second roller so that the first roller is circularly moved in a direction away from the sheet, and the support member is held by the holding means.

The sheet conveying apparatus according to claim 3 is the sheet conveying apparatus according to claim 1 or 2, wherein the holding force when the holding means keeps the first roller away from the sheet is a holding force, Is greater than a force when the support member is moved from the state in which the support member is held by the holding means to the state in which it is not held when the drive means rotates in the other direction Small.

The sheet conveying apparatus described in claim 4 is the sheet conveying apparatus according to any one of claims 1 to 3, wherein the holding means is provided on either one of the support member or the housing rotatably supporting the support member, A first member having a projection and a second member provided on the other of the support member or the housing and having a groove portion in which the projection is engaged; and a pressing member which, when the projection and the groove are engaged, And a contact surface of the groove and the protrusion is not perpendicular to the circular motion direction of the first roller.

According to a fifth aspect of the present invention, in the sheet conveying apparatus according to the fourth aspect, the holding means has a portion extending (stretched) in a direction having a component in the vertical direction from the groove portion.

An image reading apparatus according to a sixth aspect of the present invention is characterized by including the sheet conveying apparatus according to any one of the first to fifth aspects and image reading means for reading an image from a sheet conveyed by the sheet conveying apparatus.

An image forming apparatus according to a seventh aspect of the present invention is characterized by including the image reading apparatus according to claim 6 and image forming means for forming an image read by the image reading apparatus on a recording medium.

According to the invention as set forth in claim 1, as compared with a case in which the first roller for releasing the sheet is held against the sheet and the first roller is held in contact with the sheet, It is possible to reduce the force required to maintain the state of being in contact with the contact surface.

According to the invention as set forth in claim 2, when the sheet is not to be transported, the first roller can be kept away from the sheet.

According to the invention as set forth in claim 3, it is possible to prevent the first roller from being in a state of being in contact with the sheet from the state of being separated from the sheet by the action of gravity.

According to the invention as set forth in claim 4, as compared with the case where the contact surfaces of the groove and the protrusion are perpendicular to the circular motion direction of the first roller, when the sheet is not to be conveyed, the state in which the first roller is held And when the sheet is conveyed, it is possible to make it easy to move from the state where the first roller is held to the state where it is not held.

According to the invention as set forth in claim 5, as compared with the configuration in which the holding means does not have a portion extending in the direction having the component in the vertical direction from the groove portion, when the sheet is not conveyed, It becomes easy to move to the state.

According to the invention as set forth in claim 6, as compared with the case where the sheet conveying apparatus according to any one of claims 1 to 5 is not provided, the force required to keep the first roller in contact with the sheet is made small .

According to the invention as set forth in claim 7, as compared with the case in which the image reading apparatus according to claim 6 is not provided, the force required to keep the first roller in contact with the sheet can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic configuration view of an image forming apparatus provided with a sheet conveying device according to an embodiment of the present invention, viewed from the front side; Fig.
2 is a block diagram showing a hardware configuration of the sheet conveying apparatus;
Fig. 3 is an enlarged schematic view of the carry section of the sheet conveying apparatus when viewed from the front side. Fig.
4 is a perspective view of the upper transport guide and the lower transport guide as seen from the front side.
5 is an enlarged view of the carry section viewed from the front side.
6 is a perspective view of the drive mechanism viewed from the front side;
7 is a plan view of the feed roller and the pickup roller in a vertical direction.
8 is a side view showing the lock member and the hook member.
9 is a sectional view showing a state in which the lock mechanism is locked;
10 is a sectional view showing a state in which the lock mechanism is released;
11 is a schematic view for explaining the vertical movement of the pickup roller in the conventional example.

<Embodiment>

<Configuration>

1 is a schematic structural view of an image forming apparatus 100 provided with a sheet conveying apparatus 10 according to an embodiment of the present invention, viewed from the front side. Here, the front side is a surface opposed to the user when the user operates the image forming apparatus 100, provided with operating means such as a touch panel or operation keys. On the other hand, the back side is a face opposite to the front face side. The image forming apparatus 100 is composed of a sheet conveying apparatus 10, a paper feeding section 20, an image forming section 30, and an image reading section 40 in order. The sheet conveying apparatus 10 is a sheet conveying apparatus that conveys a sheet to be read as a manuscript to a reading position of the image reading section 40 and discharges the sheet after image reading. A sheet to be read as a manuscript is an example of a sheet according to the present invention. The paper feeding unit 20 feeds paper to the image forming position in the image forming unit 30. [ The image forming unit 30 forms an image on paper fed from the paper feeding unit 20 through respective processes of electrophotographic processes such as charging, exposure, development, transfer, and fixing. The image forming section 30 is a means for forming a color image in the present embodiment, but may be a means for forming a black and white image. The image reading section 40 reads an image on the original conveyed to the reading position in the sheet conveying apparatus 10 and supplies the reading result to a control section (not shown). The control unit supplies the read result to the image forming unit 30 as necessary, and the image forming unit 30 forms an image according to the supplied read result on the sheet. The image reading section 40 is an example of image reading means according to the present invention. The apparatus including at least the sheet conveying apparatus 10 and the image reading section 40 is an example of the image reading apparatus according to the present invention.

The sheet conveying apparatus 10 includes an original stacking portion 11, a discharge sheet stacking portion 12, and a conveying portion 13. The original mounting portion 11 is a dish-shaped member for mounting a sheet to be read as a manuscript. The carry section 13 is composed of a plurality of rollers, and carries the original by the rotation of these rollers. The sheet conveying apparatus 10 is attached to the image reading section 40 via an opening / closing mechanism (not shown) such as a hinge, for example. A slit glass 14 is fitted in a part of the surface of the sheet conveying apparatus 10 which is in contact with the image reading section 40. When the original is carried on the slit glass 14 by the carry section 13, the image reading section 40 transmits the slit glass 14 to read the image on the original. The original on which the image is read is discharged to the discharge paper loading section 12 by the carry section 13. [

The paper feeding section 20 includes a paper storage section 21 for storing paper and a plurality of rollers for conveying the paper stored in the paper storage section 21 to the image forming position in the image forming section 30 And a paper feeding means (22).

The image forming unit 30 forms an image by using toners of four colors of yellow (Y), magenta (M), cyan (C), and black (K) by a so-called intermediate transfer method. The image forming section 30 includes a photosensitive drum 31, a charger 32, an exposure device 33, a developing device 34, toner cartridges 35Y, 35M, 35C and 35K, A belt 36, and a fixing device 37. In addition, the letter "Y", "M", "C" or "K" at the end of the letter indicates that the element corresponds to any one of the four colors. These components are different in color of the toner to be used, but have a common structure and function in common. Hereinafter, in the description of these constituent elements, when there is no need to distinguish one from the other, the term "toner cartridge 35" is abbreviated and is collectively referred to as "toner cartridge 35".

The photoconductor drum 31 is a cylindrical member which is formed by laminating a photoconductive film on its surface and rotating about its axis, and is an image holding member for holding an electrostatic latent image formed on its surface. The charger 32 charges the photoreceptor drum 31 at a predetermined charging potential. The exposure apparatus 33 exposes the photosensitive drum 31 to form an electrostatic latent image. The developing device 34 develops the electrostatic latent image by supplying the toner to the electrostatic latent image to form an image on the surface of the photoconductive drum 31. [ The toner cartridge 35 accommodates the toner of each color and supplies it to the developing unit 34 as needed. The intermediate transfer belt 36 is means for holding a toner image transferred from the photosensitive drum 31. [ The intermediate transfer belt 36 is supported by a plurality of support rolls, and its outer circumferential surface is circumferentially rotated in the direction indicated by the arrow A1 in the figure. The fixing device 37 fixes the image on the paper by heating and pressing the paper on which the image has been transferred from the intermediate transfer belt 36. [ The photoconductor drum 31, the charger 32, the exposing device 33, the developing device 34, the intermediate transfer belt 36 and the fixing device 37 are the same as those of the image forming device It is an example. A portion of the image forming apparatus 100 excluding the sheet conveying apparatus 10 is referred to as a copying apparatus 50. [

2 is a block diagram showing the hardware configuration of the sheet conveying apparatus 10 and the copying apparatus 50. As shown in Fig. The sheet conveying apparatus 10 includes a control section 101, a storage section 102, and a communication section 103. [ Each part is electrically connected by a bus. The control unit 101 has a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and a time measuring unit for measuring time. The CPU controls each unit connected to the control unit 101 by executing a control program stored in the ROM or the storage unit 102. [ The control unit 101 is an example of the control means according to the present invention. The storage unit 102 stores a control program, for example, as a storage device such as a flash memory. The communication unit 103 communicates with the communication unit 183 of the main body of the image forming apparatus 100 under the control of the control unit 101. [

The copying apparatus 50 includes a control section 181, a storage section 182, a communication section 183, a UI section 184, and an image forming section 30. Each part is connected by a bus. The control unit 181 has a CPU, a ROM, and a RAM. The CPU controls each unit connected to the control unit 181 by executing a control program stored in the ROM or the storage unit 182. [ The storage unit 182 is, for example, a storage device such as a hard disk, and stores, for example, a control program and image data. The communication unit 183 communicates with the communication unit 103 of the sheet conveying apparatus 10 and the communication terminal operated by the user under the control of the control unit 181. [ The UI (User Interface) unit 184 includes, for example, a touch panel or a plurality of keys, and notifies the control unit 181 of an instruction based on the user's operation. The control unit 181 performs processing in accordance with an instruction notified from the UI unit 184. [ The image forming section 30 forms an image based on the image data on the paper as described above.

3 is an enlarged schematic view of the carry section 13 of the sheet conveying apparatus 10 when viewed from the front side. Hereinafter, only the main portion according to the present embodiment will be described with reference to Fig. 3, and the description of the other portions will be omitted. The conveying unit 13 includes a pickup roller 111, a feed roller 112, a discharge roller 113, a driven roller 114, a normal conveying path 130, a conveying path 131, An inversion conveying path 132, an upper conveying guide 135, and a lower conveying guide 136. As shown in Fig. 3, but also a drive mechanism (not shown in Fig. 3) for driving these rollers is also provided. However, for convenience of explanation, first, The recesses and the rollers of the part 13 will be described, and then the drive mechanism will be described.

The normal conveying path 130 conveys the original from the pickup roller 111 toward the feed roller 112 and then to the position of the slit glass 14 by a plurality of rollers, Is read and then conveyed to the position of the discharge roller 113. [ The position of the slit glass 14 is a reading position at which the image on the original is read by the image reading unit 40. [ On the other hand, the linking conveying path 131 connects the position (connection portion L2) on the upstream side in the sheet conveying direction with any position (connection portion L1) on the downstream side of the image conveying direction It is a carrier. That is, in the normal conveying path 130, the connection point L2 is located upstream of the connection point L1 in the sheet conveying direction. Hereinafter, in the case of the &quot; paper conveying direction &quot;, it refers to the direction in which the original is conveyed toward the discharge roller 113 in the usual conveying path 130. The reverse conveying path 132 is a conveying path located downstream of the connection point L1 in the sheet conveying direction and the conveying direction of the sheet is reversed in the reverse conveying path 132. [

The pickup roller 111 is located on the most upstream side in the sheet conveying direction in the normal conveying path 130 and the feed roller 112 is conveyed in the normal conveying path 130 by the sheet conveying And is rotated by the driving force generated by the driving source. An endless belt is stuck on the pickup roller 111 and the feed roller 112 so that the pickup roller 111 rotates in accordance with the rotation of the feed roller 112 and the original placed on the original stacking portion 11 is conveyed (13). The feed roller 112 conveys the document drawn by the pick-up roller 111. An electromagnetic clutch, which will be described later, is connected to the feed roller 112, and the transmission of the driving force from the driving source is controlled by the electromagnetic clutch. Hereinafter, a state in which the drive side of the electromagnetic clutch is connected to the non-drive side by the on-off control of the electromagnet in the electromagnetic clutch is referred to as a state in which the electromagnetic clutch is in the engaged state and the drive side of the electromagnetic clutch is connected to the non- It is assumed that the electromagnetic clutch is not connected. That is, when the electromagnetic clutch is disengaged, the feed roller 112 does not rotate, and the pickup roller 111 accompanying the rotation does not rotate. The pickup roller 111 is an example of the first roller according to the present invention. The feed roller 112 is an example of the second roller according to the present invention.

The discharge roller 113 is located on the inversion conveying path 132 and rotates by the driving force generated by the driving source to convey the original. The discharge roller 113 rotates in the forward rotation direction when the one-side reading of the image by the image reading unit 40 or the discharge of the original on both sides of the original to the discharge paper loading unit 12. [ The discharge roller 113 rotates in the reverse direction when the original to which the both sides of the image is not completely read is reversed, and the original is conveyed along the conveying path 131. The rotational direction of the discharge roller 113 is switched by the control section 101 controlling the rotational direction of the driving force. The driven roller 114 is provided at a position facing the discharge roller 113 and rotates in a driven manner following the rotation of the discharge roller 113. [

The upper conveying guide 135 and the lower conveying guide 136 are guiding members that guide the conveying direction of the original along the conveying path 130. When the original is conveyed, the original is guided by its upper conveying guide 135 and its lower conveying guide 136 in its proceeding direction. The upper conveying guide 135 is located above the lower conveying guide 136 in the vertical direction. The lower conveying guide 136 is upstream of the upper conveying guide 135 in the paper conveying direction and guides the conveyance of the document along the normal conveying path 130. The upper conveying guide 135 and the lower conveying guide 136 are connected to each other by a connecting portion 137 at a position where the end portions farther from the discharge roller 113 are in contact with each other.

4 is a perspective view of the upper conveying guide 135 and the lower conveying guide 136 viewed from the front side. The upper conveying guide 135 and the lower conveying guide 136 have a comb-like shape at the end near the connecting portion 137. The upper conveying guide 135 and the lower conveying guide 136 are connected to each other by a rotating shaft extending in the depth direction in a state where the comb teeth are engaged with each other in the connecting portion 137. Thus, the upper conveying guide 135 is rotatable in the direction away from the lower conveying guide 136 about the rotating shaft of the connecting portion 137. [ For example, when a paper jam occurs in the sheet conveying apparatus 10, the user rotates the upper conveying guide 135 in the direction away from the lower conveying guide 136 to open the upper conveying guide 135, The conveying path 130 is exposed to the outside, and the jammed document is removed. The control section 101 stops power supply to the motor 140 and the electromagnetic clutch 143 and the electromagnet in the electromagnetic clutch 143 is controlled to be off, The electromagnetic clutch 143 is disengaged. Next, the drive mechanism will be described.

5 is an enlarged view of the drive mechanism of the carry section 13 when viewed from the front side. In this figure, members such as rolls and gears constituting the drive mechanism are shown in a transparent manner. Hereinafter, only the essential parts according to the present embodiment will be described with reference to Fig. 5, and the description of the other parts will be omitted. In Fig. 5, in order to express the position in the depth direction of each member, a step is provided at the depth, and the member at the depth position of each step is indicated by a line of a different shape. First, a member positioned most deeply when viewed from the front side of the carry section 13 is indicated by a solid line. In addition, a broken line indicates a member positioned one step ahead of the member indicated by the solid line. In addition, a member positioned one step further from the member indicated by the broken line is indicated by a dashed line. In addition, a member positioned one step further forward than a member indicated by a one-dot chain line is indicated by a chain double-dashed line. The members of the driving mechanism represented by the lines of these respective shapes are located on the rear side of the respective rollers. Each roller is shown by a solid line thicker than the member of the driving mechanism. In addition, the description of the parts that have been described in Fig. 3 will be omitted.

The carry section 13 includes a motor 140, a large diameter gear 141, a small diameter gear 142, an electromagnetic clutch 143 and gears 144, 145 and 146 as a drive mechanism. The motor 140 shown in the drawing actually represents a gear that is directly connected to the drive shaft of the motor. The large-diameter gear 141 and the small-diameter gear 142 have the same rotation axis and are, for example, two-stage gears. The electromagnetic clutch 143 and the gear 144 have the same rotation axis and are, for example, two-stage gears. The electromagnetic clutch 143 has gears that are brought into and out of contact with the driven side by the action of an electromagnet, and the gears are engaged with the respective gears. The gear 146 is connected to the rotation shaft of the feed roller 112. The gear 146 transmits the driving force generated by the motor 140 to the feed roller 112 to which the gear 146 is connected.

The motor 140 selectively rotates in the forward direction and the reverse direction opposite to the forward direction to generate the driving force. The motor 140 is an example of the driving means according to the present invention. Here, the case where the motor 140 rotates in the forward direction will be described as an example, and the transmission of the driving force between the rollers and the gears will be described. When the motor 140 rotates in the forward direction, the gear directly connected to the drive shaft of the motor 140 rotates in the direction of the arrow R1 shown. Accordingly, the large-diameter gear 141 engaged with the gear of the motor 140 rotates in the direction of arrow R2, and accordingly the small-diameter gear 142 rotates in the same direction R3. The small-diameter gear 142 is engaged with the gear of the electromagnetic clutch 143. Thus, the driving-side gear of the electromagnetic clutch 143 rotates in the direction of arrow R4. The electromagnetic clutch 143 controls the transmission of the driving force to the gear 144. That is, when the driving-side gear of the electromagnetic clutch 143 is in a state of being separated from the driven side (i.e., disconnected state), the driving force is not transmitted to the gear 144. On the other hand, when the drive-side gear of the electromagnetic clutch 143 is in a state of being connected to the driven side (i.e., connected state), the drive force is transmitted to the gear 144 and the gear 144 rotates in the direction of the arrow R5 . The gear 144 meshes with the gear 145, and the gear 145 meshes with the gear 146. As a result, the gear 145 rotates in the direction of arrow R6 and the gear 146 rotates in the direction of arrow R7 shown. The gear 146 transmits the driving force to the feed roller 112, and the feed roller 112 rotates in the direction of arrow R8 to convey the original. The large diameter gear 141, the small diameter gear 142, the electromagnetic clutch 143 and the gears 144, 145 and 146 are examples of the first transmission mechanism according to the present invention.

6 is a perspective view of the driving mechanism viewed from the front side. 7 is a plan view of the feed roller 112 and the pickup roller 111 in a vertical direction. In Fig. 6, the teeth of some of the gears are omitted for easy viewing. The rotary shaft 151a connected to the gear 146 and the rotary shaft 151b connected to the feed roller 112 are connected to the output shaft of the torque limiter 152 provided at a position sandwiched between the gear 146 and the feed roller 112 And is connected as a rotary shaft 151 of the same axis. The torque limiter 152 is a device for limiting or blocking the transmission of the torque to the rotary shaft 151b when the torque of the rotary shaft 151a exceeds a predetermined set value. Thus, the driving force transmitted from the motor 140 to the feed roller 112 is controlled. The feed roller 112 and the feed roller 112 are fixed to each other so as to cover the rotational axis 151b of the feed roller 112 and the rotational axis 153 of the pickup roller 111 at a position sandwiched between the torque limiter 152 and the feed roller 112, A belt accommodating frame 154 is provided. A belt 155 is provided on the rotation axis 151b of the feed roller 112 and the rotation axis 153 of the pickup roller 111 in the belt accommodating frame 154. [ The driving force resulting from the rotation of the rotary shaft 151b is transmitted to the rotary shaft 153 via the belt 155 so that the pickup roller 111 rotates in the same direction as the feed roller 112. [ The belt 155 is an example of the second transmission mechanism according to the present invention.

The pickup roller 111 rotates the support shaft 156 about the rotation axis 151b of the feed roller 112 along the rotation of the support frame 156 about the rotation axis 151b of the feed roller 112 when the motor 140 rotates in the forward direction, (To be described later) in the direction of the arrow Rk, and moves down to the position in contact with the original. Further, the pickup roller 111 conveys the rotation of the feed roller 112 and rotates, thereby conveying the original in contact therewith. When the motor 140 rotates in the reverse direction, the pickup roller 111 rotates the support shaft 156 around the rotation axis 151b along with the rotation of the support frame 156 about the rotation axis 151b of the feed roller 112, And moves up to a position not in contact with the original. Hereinafter, it is assumed that the pickup roller 111 is in a position in which the pickup roller 111 descends in the vertical direction and comes into contact with the original as a result of circular motion around the rotary shaft 151b. It is to be noted that the pickup roller 111 moves upward with respect to the vertical direction as a result of performing the circular motion around the rotary shaft 151b as a center, .

The pickup roller 111 is rotatably supported on the rotary shaft 151b of the feed roller 112 and the rotary shaft 153 of the pickup roller 111 at the end far from the gear 146, A support frame 156 rotatable about the rotation axis of the support frame 112 is provided. The support frame 156 is an example of a support member according to the present invention. The support frame 156 also rotates about the rotation axis 151b of the feed roller 112 in accordance with the rotation of the feed roller 112. As a result, And operates on the roller 111. A stopper 157 for catching a gate lock member, which will be described later, is provided at an end of the support frame 156 closer to the rotation shaft 153. A hook member 160 is provided at a position where the support frame 156 is sandwiched between the feed roller 112 and the pickup roller 111. The hook-shaped member 160 has a projecting portion 161 of the hook at the tip which is drawn upward with respect to the vertical direction. The hook member 160 is engaged with the lock member 170 attached to the upper conveying guide 135 to keep the pickup roller 111 lifted up in the vertical direction.

8 is a side view showing the lock member 170 and the hook member 160. Fig. The lock member 170 extends in the vertical direction from the end attached to the upper conveying guide 135. [ A portion of the extending portion of the lock member 170 bent toward the hook member 160 is referred to as a groove portion 176. [ The projecting portion 161 of the hook member 160 is engaged with the groove portion 176 of the lock member 170. [

When the pick-up roller 111 is in the lowered state at the timing when the user sets the original on the original placement section 11 before the conveyance of the original is started, the tip of the original comes into contact with the pickup roller 111, The document can not be set. Thus, in the present embodiment, during the period when the original is not conveyed, the lock member 170 and the hook member 160 are engaged with each other, so that the pickup roller 111 is maintained in the raised state. Accordingly, it is easy for the user to accurately set the original on the manuscript loading section 11 so that the top surface of the original is disposed below the pickup roller 111.

The lock member 170 has a shaft 171 extending in the direction along the rotation axis 151 and the rotation axis 153 at the end opposite to the side where the hook member 160 is engaged with the hook member 160. Both ends of the shaft 171 are rotatably attached to bearings provided on the upper conveying guide 135. [ A coil spring 172 is wound around the shaft 171. One end of the coil spring 172 extends in a direction orthogonal to the shaft 171. The spring end 173 of the coil spring 172 is bent into a hook shape toward the upper conveying guide 135 and contacts the upper conveying guide 135 . When the force in the direction of the arrow Ra1 is applied to the lock member 170, the shaft 171 rotates and a force in the direction of the arrow Ra1 also acts on the coil spring 172 wound on the shaft 171. The spring tip 173 of the coil spring 172 is pushed by the upper conveying guide 135 by the force in the direction of the arrow Ra1 so that the spring tip 173 is urged from the upper conveying guide 135 by a force . As a result, a force in the direction of the arrow Ra2 acts on the shaft 171 on which the coil spring 172 is wound and the lock member 170 connected to the shaft 171. That is, the coil spring 172 generates a force that opposes the force acting in the direction of approaching the upper conveying guide 135, in the direction opposite to the conveying direction, in the direction of the downstream side of the locking member 170 . Thus, when the hook member 160 and the lock member 170 are engaged with each other, a reaction force acts in the direction of the arrow Ra2 with respect to the force acting in the direction of the arrow Ra1 with respect to the lock member 170, The member 160 and the lock member 170 are pressed against each other.

As described above, the hook-shaped member 160 is engaged with the lock member 170, so that the support frame 156 is held in a state in which the pickup roller 111 is separated from the original. The hook member 160, the protrusion 161, the lock member 170, the shaft 171, the coil spring 172, the spring tip 173 and the groove 176 are examples of the holding means according to the present invention . The upper transport guide 135 is an example of a housing according to the present invention. The hook member 160 is an example of the first member according to the present invention, and the lock member 170 is an example of the second member according to the present invention. The protrusion 161, the shaft 171, the coil spring 172, the spring tip 173, and the groove 176 are examples of the pressing means according to the present invention. Hereinafter, both the hook member 160 and the lock member 170 are referred to as a lock mechanism. Hereinafter, the state in which the hook member 160 and the lock member 170 are engaged with each other will be referred to as a locked state of the lock mechanism. Hereinafter, a state in which the hook member 160 and the lock member 170 are not engaged with each other is referred to as a state in which the lock mechanism is released.

9 is a sectional view showing a state in which the lock mechanism is locked. The controller 101 controls the motor 140 to rotate in the reverse direction so that the pickup roller 111 is in the raised state as an operation for conveying the next original after the initial operation or the conveyance of the original is completed . Here, the initial operation is an operation performed immediately after the power of the image forming apparatus 100 is turned on, for example, or immediately after an error such as paper jam is solved. The feed roller 112 rotates in the direction of the arrow Rb1 and the supporting frame 156 is rotated in the direction of the arrow Rb1 by the rotation of the motor 140 in the reverse direction, The pickup roller 111 performs circular motion in the direction of the arrow Rc1. As a result, the hook member 160 moves in the direction of arrow Rc1 so that the protrusion 161 of the hook member 160 is engaged with the groove portion 160 provided on the surface of the lock member 170, (176), the lock mechanism is locked. The back angle formed by one slope forming the groove 176 and the other slope is designed to be larger than a right angle. The projecting portion 161 has a shape that becomes a triangle when viewed from the front side, and its lower surface 162 is engaged with the groove portion 176. The contacting surfaces of the groove portion 176 and the protruding portion 161 at the moment when the locking mechanism is locked or at the moment when the lock is released are not perpendicular to the circular motion direction of the pickup roller 111, The resistance tends to be small and the resistance tends to be small even when the protruding portion 161 is removed from the groove portion 176. In addition,

The lock member 170 has a side surface portion 177 which is a portion extending from the groove portion 176 in a direction having components in the vertical direction. The length of the side surface portion 177 is set such that the bottom surface 162 of the protrusion portion 161 slides in contact with the side surface portion 177 and moves toward the groove portion 176 so that the protrusion portion 161 easily catches in the groove portion 176 The lag length is fixed. Further, the lock member 170, which is the locked side, is located on the rotational center side in the circular motion of the pickup roller 111 with respect to the hook member 160 which is the side where the lock mechanism performs locking. Thus, when the lock mechanism is released, that is, when the pickup roller 111 performs circular motion in the direction of the arrow Rc2, the direction of the force applied from the hook member 160 to the lock member 170 follows the rotational direction Therefore, resistance against this force is not generated, and the lock is released smoothly.

In the lower conveying guide 136, on the downstream side of the pick-up roller 111 in the sheet conveying direction as the upstream side in the sheet conveying direction with respect to the feed roller 112, the original can be set in the original placing portion 11 at a proper position And a gate member 200 serving as a reference of the set position of the original end. The gate member 200 has a spring (not shown). When receiving the force in the sheet conveying direction, the gate member 200 collapses in the sheet conveying direction to make the sheet conveying path open. Further, when the gate member 200 is not receiving the force in the sheet conveying direction, the gate member 200 is in a state of being raised with respect to the horizontal direction by the force of the spring. The gate member 200 is engaged with the gate lock member 190 to be described later so as not to collapse even if a force is applied in the sheet conveying direction, that is, when the original is set.

The gate member tip end 201 of the gate member 200 is bent in a hook shape toward the paper conveying direction. The gate lock member 190 is a bar member and has a first hook portion 191 at one end closer to the feed roller 112 and a second hook portion 191 at the other end farther from the feed roller 112. [ (192). The gate lock member 190 has a shaft 193 extending in the direction along the rotational shaft 151 and the rotational shaft 153 at a middle position in the longitudinal direction thereof. The shaft 193 is fitted in a bearing 139 provided in the upper conveying guide 135 and the gate locking member 190 is rotatable with respect to the upper conveying guide 135.

The holding force when the projection 161 of the hook member 160 and the groove portion 176 of the lock member 170 are held in contact with each other is set such that the pickup roller 111 is pulled in the vertical direction by its own weight Is larger than the force to separate the projection 161 of the hook member 160 from the groove 176 of the lock member 170. [ This holding force is obtained by rotating the motor 140 in the forward direction (the direction indicated by the arrow Rb2) so that the pickup roller 111 performs the circular motion in the direction of the arrow Rc2 so that the protrusion 161 of the hook- And the groove portion 176 of the lock member 170 are separated from each other. In other words, the holding force is smaller than the force when the support frame 156 is moved from the state in which it is held by the holding means to the state in which it is not held. Therefore, during the initial operation, for example, when the motor 140 rotates in the reverse direction, the pickup roller 111 is lifted up and the lock mechanism by the hook member 160 and the lock member 170 is locked The lock is not released by the weight of the pickup roller 111. [ On the other hand, when the document is conveyed, the motor 140 rotates in the forward direction, whereby the lock of the lock mechanism is released by the torque applied to the rotary shaft 151b, and the pickup roller 111 is in the lowered state.

10 is a side view showing a state in which the lock mechanism is released; For example, when the user presses down the copy start button or the scan start button to start conveyance of the original, as described above, the motor 140 rotates in the forward direction, The lock of the lock mechanism is released by the torque, and the pickup roller 111 is brought down. At this time, the stopper 157 of the support frame 156 is caught by the second hook portion 192 of the gate lock member 190 and pressed down by the circular movement of the pickup roller 111, The member 190 rotates about the shaft 193 in the direction of the arrow Rd1. As a result, the first hook portion 191 of the gate lock member 190 is disengaged from the gate member distal end 201 of the gate member 200. In this state, when the gate member 200 receives a force in the conveying direction from the original to be conveyed, the engagement between the first hook portion 191 and the gate member front end 201 is eliminated, The conveyance of the document is not disturbed by collapsing in the conveying direction.

Here, the effect of the present embodiment will be described in comparison with the conventional configuration of this embodiment. 11A and 11B are schematic diagrams for explaining the up-and-down movement of the pickup roller 111a in the conventional example. 11 (a) shows a state in which the pickup roller 111a is lifted, and FIG. 11 (b) shows a state in which the pickup roller 111a is in a downward state. In the conventional example, the feed roller 112a and the pickup roller 111a are rotatably supported from the surface of the upper transport guide 135a, which faces the paper transport path, to raise the pickup roller 111a A spring 301 is attached to the middle of the longitudinal direction of the support frame 156a. One end of the spring 301 is attached to the upper transport guide 135 and the other end of the spring 301 is attached to the support frame 156a. The pickup roller 111a is pulled up to the upper conveying guide 135 side by the force by which the spring 301 is reduced.

In the conventional example, when the document is conveyed, as the feed roller 112a rotates in the Re1 direction in accordance with the rotation of the motor 140 in the forward direction, the support frame 156a The pickup roller 111a rotates about the feed roller 112a so that circular motion is performed in the direction of arrow Rf1 about the rotary shaft 151d. As a result, the pickup roller 111a moves to a position in the vertical direction. At this time, the torque applied to the rotating shaft 151d is pulled in the opposite direction against the torque required for rotating the feed roller 112a and circularly moving the pickup roller 111a and the force for reducing the spring 301 The torque necessary for maintaining the state of contact with the paper is adjusted. That is, if the pick-up roller 111a is lifted using the force that the spring 301 reduces, the torque required for bringing the pick-up roller 111a down is caused by the rotation of the feed roller 112a Not only the torque for causing the pickup roller 111a to perform the circular motion but also the torque for continuing the resistance to the reduction of the spring 301 is required. That is, in such a case, since the torque applied to the rotary shaft 151b also increases, the torque limiter provided on the rotary shaft of the feed roller 112a also needs to be large accordingly. As a result, . Further, in such a case, the motor 140 also becomes large in proportion to the required torque, which is also costly and is problematic in terms of space saving.

On the other hand, in the present embodiment, by providing the lock mechanism, once the pickup roller 111 is lifted and the lock mechanism is locked, the pickup roller 111 is maintained in the up state, so that additional torque is not required Do not. That is, in this embodiment, it is not necessary to continuously pull the pickup roller 111 by the spring 301 as in the conventional example described above. Therefore, in the present embodiment, the torque necessary for bringing the pickup roller 111 into the lowered state is sufficient to rotate the feed roller 112 and to cause the pickup roller 111 to perform the circular motion. As a result, the torque applied to the rotating shaft 151b does not include the torque that continues to resist the spring 301 as in the conventional example described above, and the motor 140 is required when the pickup roller 111 is lifted up Is small. Thus, the torque limiter 152 and the motor 140 provided on the rotary shaft 151 can be downsized.

In the present embodiment, the torque generated by the driving of the motor 140 is not applied to the torque for resisting the spring 301 as in the conventional example, but the feed roller 112 is rotated and the pickup roller 111) can be used only as a torque for circular motion. Accordingly, the force generated by the torque is sufficiently transmitted when the pickup roller 111 comes into contact with the paper, and the document is conveyed with the contact pressure applied to the document increased.

Although the spring 301 is not used as in the above-described conventional example, in the case of a configuration not having the lock mechanism similar to the present embodiment, the following is obtained. That is, in this case, when the document is not conveyed, the motor 140 rotates in the reverse direction, and the direction in which the pickup roller 111 approaches the upper conveying guide 135 about the rotary shaft 151 At this time, there is no mechanism for maintaining the lifted state. Therefore, when the upper conveying guide 135 is rotated relative to the lower conveying guide 136 to bring the sheet conveying apparatus 10 into the open state, the electromagnetic clutch 143 is disengaged, The pickup roller 111 descends in the vertical direction due to its own weight. Thereby, the control section 101 needs to rotate the motor 140 in the reverse direction to bring the pickup roller 111 up again in preparation for the start of conveyance of the original. On the other hand, in the present embodiment, even if the upper conveying guide 135 is rotated with respect to the lower conveying guide 136 and the sheet conveying apparatus 10 is opened, the pickup roller 111 is not brought down by its own weight Therefore, the control section 101 does not need to rotate the motor 140 in the reverse direction to bring the pickup roller 111 up. As a result, compared to the case in which the lock mechanism is not provided, in the present embodiment, there is no loss of time at the time of starting the conveyance of the document.

As described above, according to the present embodiment, in the sheet conveying apparatus 10, the torque required by the motor 140 can be reduced when the pick-up roller 111 located at the most upstream in the conveying direction is lifted in the vertical direction .

(Modified example)

The second transmission mechanism in the present invention may be a gear wheel instead of a belt. In this case, however, it is necessary that the rotation of the feed roller 112 be transmitted to the pickup roller 111 and the pickup roller 111 circularly move as the support frame 156 rotates.

10: sheet conveying device 11: original loading section
12: discharge paper loading unit 13:
14: slit glass 20: paper feed unit
21: paper receiving portion 22: paper feeding means
30: image forming section 31: photosensitive drum
32: Charger 33: Exposure device
34: Developing device 35: Toner cartridge
36: intermediate transfer belt 37: fixing device
40: image reading section 101:
102: storage unit 103: communication unit
111: pick-up roller 112: feed roller
113: discharge roller 114: driven roller
130: Conventional conveying path 131: Coupling conveying path
132: reverse conveying path 135: upper conveying guide
136: Lower conveying guide 137:
139: Bearing 140: Motor
141: Large diameter gear 142: Small diameter gear
143: electromagnetic clutches 144, 145, 146:
151, 151a, 151b, 153: rotary shaft 152: torque limiter
154: Belt storage frame 155: Belt
156: support frame 157: stopper
160: hook member 161:
162: lower surface 170: lock member
171, 193: shaft 172: coil spring
173: leading end 176:
177: Side 181:
182: storage unit 183: communication unit
184: UI section 190: Gate lock member
191: second hook portion 192: third hook portion
200: gate member 201: gate member tip

Claims (7)

A first roller for feeding the sheet by rotating,
A second roller for conveying (conveying) the sheet fed out by the first roller by rotating,
A support member rotatably supporting the first roller and rotatable about a rotation axis of the second roller,
Holding means for holding the support member in a state in which the first roller is separated from the sheet,
Driving means for generating a driving force by rotating,
A first transmitting mechanism for transmitting the driving force generated by the driving means to the second roller and rotating the second roller,
A second transmission mechanism for transmitting the driving force transmitted to the second roller to the first roller and rotating the first roller in a direction common to the second roller,
Wherein when the sheet is transported, the driving means is rotated to rotate the first roller and the second roller in a direction in which the sheet is transported, The holding member held by the means is rotated about the rotation axis of the second roller so that the first roller is not circularly moved in the direction approaching the sheet so as not to be held by the holding means, And a control means for bringing the first roller into contact with the sheet
And a sheet conveying device for conveying the sheet conveyed by the sheet conveying device. The method according to claim 1,
Wherein when the sheet is not to be conveyed, the control means rotates the driving means in a direction opposite to the direction in which the sheet is conveyed, and rotates the support member about the rotation axis of the second roller, 1 roller is circularly moved in a direction away from the sheet, and the support member is held by the holding means. 3. The method according to claim 1 or 2,
The holding force when the holding means keeps the first roller away from the seat is greater than the force acting in the vertical direction by the weight of the supporting member and the first roller, Is smaller than a force at the time when the support member is to be moved from the state in which the support member is held by the holding means to the state in which it is not held when the support member is rotated in the other direction. 3. The method according to claim 1 or 2,
The holding means,
A first member having a protrusion provided on either the support member or a housing rotatably supporting the support member;
A second member provided on the other of the support member or the housing and having a groove portion to which the projection is engaged,
And pressing means for pressing the protruding portion and the groove portion against each other when the protruding portion and the groove portion are engaged,
Wherein a contact surface of the groove and the projection is not perpendicular to the circular motion direction of the first roller. 5. The method of claim 4,
Wherein the holding means has a portion extending (stretched) in a direction having a component in the vertical direction from the groove portion. A sheet conveying device according to any one of claims 1 to 3,
An image reading means for reading an image from a sheet conveyed by the sheet conveying device
The image reading apparatus comprising: An image reading device according to claim 6,
Image forming means for forming an image read by the image reading apparatus on a recording medium
The image forming apparatus comprising:

Images