JP2006176290A - Double-sided image reader - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double-sided image reader capable of reading a double-sided image by combining switching of the mechanism transmission with this control, mainly performing reciprocal rotation control, and using a single driving source. <P>SOLUTION: In a general U-turn document carrying system, a means for operating a document feeding means at a rate of one time to N times, is composed of a control ring for restricting a rocking arm and a position of the rocking arm in two ways. As a result, a document carrying roller rotating in both reciprocal directions, a driving source of a reversing means for always rotating only in one direction and a driving source of a separating means, can be performed by the same motor, and the double-sided image reader and an inexpensive option (post-installation) double-sided device capable of reducing cost and the size of the device, can be provided. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a document feeding apparatus such as a sheet, an image reading apparatus including the same, and a series of image processing systems such as an image forming apparatus, and more particularly, has a function of reading one or both sides of a sheet fed by a document feeding unit. The present invention relates to a double-sided image reading apparatus provided.

  Some conventional image reading apparatuses have a document discharge loop path dedicated to double-sided reading (see, for example, Patent Document 1).

  In addition, when performing double-sided reading, there is also a type in which a document is once discharged out of the apparatus and read back for switching (see, for example, Patent Document 2).

  Hereinafter, the prior art will be described with reference to FIGS. In addition, description numbers, such as parts and a structure, are the same as literature.

  The document double-side reading apparatus disclosed in Patent Document 1 first scans the surface of a document by passing it over a reading glass 16, conveys the document in a direction held by rollers 9 and 18 by a flapper 8, and stack guide 12. The document is conveyed in the direction of.

  Next, the flapper 8 is switched while the trailing edge of the document is held between the rollers 9 and 18, and the document is conveyed in the reverse direction, and the roller 6 conveys the document.

  Next, the original moves while the back surface is directed toward the reading glass 16, and after scanning of the image, the original is conveyed in the direction of the stack guide 12 along a path in which the flapper 8 is held between rollers 9 and 19, unlike the above.

  In the meantime, the introduction roller 2 and the conveyance roller 3 pull out the next original and convey it in the direction of the roller 6.

  The position of the flapper 8 is switched, and the first original is discharged from the roller 20 with the surface of the original facing down through a U-shaped discharge path in a direction in which the second original is held between the rollers 9 and 18. Is done.

  In the present invention, it is shown that a dedicated U-turn path for discharging a document whose both sides have been read is provided.

  Next, in Patent Document 2 shown in FIG. 22, first, the flapper 11 is lowered to convey the document in the direction of the opening 20. The conveyance direction is reversed while the trailing edge of the document is held between the rollers 10 and 22, and the document is conveyed to the image reading unit X by the roller 5, and the back side of the document is scanned.

  The flapper 12 guides the document around the roller 5, and the document is conveyed again toward the opening 20.

  At that time, since the trailing edge of the document may still remain on the roller 10, the roller 22 is moved to the information so as to be separated from the roller 10, and the document passes through the gap toward the opening 20.

  When the leading edge of the document passes through the flapper 11, the roller 22 is moved downward and held with the roller 10, the document is reversed and conveyed in the same manner as described above, and the document reading unit X scans the document surface.

  The flapper 12 moves so that the document is guided in the direction of the roller 6, and the document is discharged from the roller 6 with the surface facing down.

  Therefore, the present invention is provided with a configuration for temporarily discharging the document to the outside of the apparatus.

  Next, in Patent Document 3 shown in FIG. 23, there are gears 61 and 62 having a one-way clutch, which are arranged so as to be locked in opposite directions, regardless of the rotational direction of the drive input shaft 53a. The rotation direction of the output shaft 22a is constant.

  In the present invention, there is an effect that the document reversing means is operated by reversing the motor to convey the document in the reverse direction, and the conveying means is operated so as to feed the document in the forward direction at the document scanning position.

That is, there is shown a double-sided document conveying device having a configuration in which the rotation direction on the output side is made constant regardless of the rotation direction on the drive input side.
JP 2001-278551 A JP 9-328263 A Japanese Patent Laid-Open No. 2002-120948

  However, the conventional configuration has the following problems.

  In both Patent Document 1 and Patent Document 2, since the means for performing double-sided reading is incorporated in the same apparatus as other means, for example, the original separating means and the original discharging means, the single-sided reading means and the double-sided reading means Could not be separated.

  In other words, the user cannot add a double-sided reading mechanism to the original single-sided scanning device later and re-create the original double-sided scanning device. As a result, the user sometimes purchased an expensive device including a useless function.

  These conventional devices cannot provide a device that can be expanded from a minimum necessary function to a more fulfilling function at a low cost, and it is difficult to improve convenience according to the use conditions of the user. .

  Further, in Patent Document 3, it is necessary to use an electromagnetic clutch in order to perform the document drawing operation by the document feeding unit (document separating unit), and there is a problem of increasing the apparatus cost.

  The present invention has been made paying attention to the above points, and uses a single drive source as a whole, and only performs forward / reverse rotation control to perform document separation operation, drive transmission switching, and transmission on / off. It is an object of the present invention to provide a double-sided image reading apparatus capable of reading both sides of an original without requiring an expensive electromagnetic clutch or control structure.

  The present invention has been made paying attention to the above points, and has solved the above problems by including the following configuration.

(1) Double-sided image reading comprising: a document conveying mechanism comprising a sheet-like document conveying means and a document discharging means; a document reversing and conveying mechanism comprising a reversing and conveying means for reversing a sheet-like document for duplex reading; and a reading means. In the device,
The document conveying mechanism and the document reversing and conveying mechanism are connected to a single motor, and the document separating means is provided in the document conveying mechanism. A double-sided image reading apparatus characterized by performing a document separation operation.

(2) having swinging means for pivotally connecting the center axis of the second gear with the center of the first gear for operating the document separating means as a fulcrum; A drive train for transmitting the power of the gear to the third gear, wherein the swinging means can stop at two kinds of positions according to the rotation direction of the first gear;
When the first gear rotates in the first direction, the swinging means moves to the first position and the second gear moves away from the third gear;
When the first gear rotates in the direction opposite to the first direction, the swinging means moves to the second position, and the second gear and the third gear can be connected at the second position. The double-sided image reading apparatus according to (1), further comprising a gear separation unit that can set two states in an incapable state.

  (3) The second gear and third gear connecting / separating means includes a convex portion that maintains the distance between the second gear and the third gear so that the gear does not mesh with the second gear, and the second gear. Is a ring with alternating recesses on the circumference that keep the distance between the shaft and the third gear meshing with each other, rotating in one direction and stopping at a predetermined angle, rotating in the opposite direction (2) The double-sided image reading apparatus according to (1) or (2), further including a latch unit that does not perform the latching.

  According to the first aspect of the present invention, it is possible to control whether or not to perform the document separation operation only by the forward / reverse rotation control of the motor in the image reading apparatus having the both-side reversing means of the document, such as an electromagnetic clutch. A double-sided document reading apparatus can be configured with an inexpensive configuration without using expensive means.

  According to the second aspect of the present invention, the gear separating means can set two kinds of states, that is, the state in which the rocking gear can be driven and connected in the drive transmission direction and the state in which the rocking gear cannot be connected. The operation of the separating means can be controlled only by controlling forward / reverse rotation of the motor of the double-sided image reading apparatus with an inexpensive configuration without using any means.

  According to the third aspect of the present invention, the separating hand of the oscillating gear is constituted by a ring having a convex part and a concave part on the circumference and a latch means, and an inexpensive construction without using an expensive means such as an electromagnetic clutch. Thus, the operation of the separating means can be controlled only by controlling the forward / reverse rotation of the motor of the double-sided image reading apparatus.

  The best mode for carrying out the present invention will be described below based on examples.

  First, the overall configuration will be described with reference to FIGS.

  FIG. 1 is a perspective view of a double-sided image reading apparatus according to an embodiment of the present invention, and FIG. 2 is a detailed sectional view. In the figure, reference numeral 50 denotes an image reading apparatus, and 1 denotes a document feeding apparatus attached to the upper part of the image reading apparatus 50. Reference numeral 2 denotes a document placing table, and 3 a document discharge table, which serves as a document pressing plate when reading a book document. Reference numerals 4a and 4b denote sliders which are provided on the document placing table 2 and move in the width direction perpendicular to the document transport direction to align both side edges of the document placed on the document placing table 2.

  Reference numeral 1a denotes an apparatus main body of the document feeder 1. The apparatus main body 1a includes a substantially U-shaped original conveyance path (hereinafter referred to as a first original conveyance path) as shown in FIG. , Referred to as a U-turn path). A lower guide frame 21 that constitutes a sheet placing portion together with the document placing table 2 is provided so as to be connected to the upstream end side of the U-turn path 14, and the document is connected to the downstream end side of the U-turn path 14. A discharge table 3 is provided.

  Further, in the upstream portion of the U-turn path 14, a pickup roller 10 which is a document feeding unit that contacts and feeds the uppermost document S stacked on the document table 2 and is sent out by the pickup roller 10. Separation pad 15 that constitutes a separation unit that separates the document S one by one, a separation roller 5 that is in pressure contact with the separation pad 15, and a document stopper that regulates the tip position of the document S stacked on the document table 2. 9 and a document presence / absence sensor 6 for detecting the presence / absence of the document S on the document placing table.

  Further, on the downstream end side of the U-turn path 14, a pair of discharge rollers 11 a and 11 b corresponding to a document discharge unit for discharging the document S to the document discharge table 3, and the leading and trailing ends of the document S A first document edge sensor 8 for detecting the above is provided.

  In the figure, the transport roller 7 constitutes a document transport unit together with the first to fourth transport rollers 7a to 7d, and transports the document S while pinching it. Reference numeral 16 denotes a pickup arm that is rotatably provided coaxially with the axis of the separation roller 5, and the pickup roller 10 is rotatably held at a rotating end of the pickup arm 16. In the present embodiment, the conveyance mechanism using one roller is used, but the same effect can be obtained by a conveyance mechanism including a plurality of roller pairs.

  The pickup roller 16 disposed above the lower guide frame 21 is held by the pickup arm 16 serving as a holding means so that the document S can be brought into contact with and separated from the document S. It contacts the document S while rotating in accordance with the downward rotation.

  When the operator places the document S on the document placing table 2 and sets it, the operator sets the document with the image surface facing upward. The leading edge position of the document S is regulated by the document stopper 9 and the presence / absence of the document is detected by the document presence / absence sensor 6. As will be described later, the document stopper 9 is pushed down by the pickup arm 16 when the pickup arm 16 rotates downward.

  Reference numeral 1 c denotes an image reading unit for reading the document S conveyed by the pickup roller 10 and the conveying roller 7, and the image reading unit 1 c includes a reading glass 12 and a contact image sensor 13 provided below the reading glass 12. (Hereinafter referred to as CIS: Contact Image Sensor). In this embodiment, the CIS is adopted, but the same effect can be obtained even with a reduction optical system using a CCD.

  Here, the CIS 13 irradiates the image information surface of the document S with light from an LED array (not shown) as a light source, and forms reflected light reflected on the image information surface on a sensor element with a SELFOC lens (trademark). Image information is read.

  The above configuration shows a single-sided reading configuration that can be applied when a document is single-sided.

  Reference numeral 1b denotes a detachable document reversing unit that enables double-sided reading at the feature of the present invention. It is configured to be detachable in the direction of the arrow shown in FIG. For example, the attachment / detachment means may be provided with an insertion piece and an insertion hole that can be engaged with the insertion piece at a desired location on the abutting surface between the apparatus main body 1a and the document reversing unit 1b (not shown). .

  Reference numeral 32 denotes a second document conveyance path configured in a substantially U shape, and includes an outer peripheral guide 27 and an inner peripheral guide 26. The document is conveyed by the reversing roller 23 corresponding to the document reversing means and the opposing rollers 23a and 23b.

  Reference numeral 29 denotes a second document edge sensor, which detects the leading edge of the document that passes through the second document transport path 32 toward the reading position.

  Reference numeral 33 denotes a double-sided document conveyance path, and reference numeral 37 denotes a paper discharge flapper. A drive source (not shown) separates whether the document S is conveyed in the direction of the second document conveyance path 32 or in the direction of the double-sided document conveyance path 33. The original S that has passed through the double-sided document transport path 33 is discharged onto a double-sided paper discharge tray 36 by a pair of double-sided paper discharge rollers 35a and 35b. The double-sided document conveyance path 33 has a U-shaped structure, and the document S can be discharged while the front and back of the document S to be discharged are reversed. That is, since the originals are continuously stacked on the double-sided paper output tray 36 with the front side facing down, all the originals can be discharged while maintaining the page order.

  When the operator gives an instruction to start reading from an operation unit (not shown), first, a motor (not shown) rotates and the pickup arm 16 rotates downward, whereby the document stopper 6 is pushed down. Thereafter, the pickup roller 10 comes into contact with the uppermost document S stacked on the document table 2 and sends out the uppermost document S.

  Next, the uppermost document S passes through the upper end surface of the depressed document stopper 9, is separated from other documents by the separation roller 5 and the separation pad 15, and is fed into the U-turn path 14. Further, the document S sent into the U-turn path 14 in this way is read by the CIS 13 on the surface of the document S in the image reading unit 1c by the rollers 7a to 7d facing the conveying roller 7. It is conveyed toward the reading position.

  Meanwhile, when the leading edge of the document S is detected by the first document edge sensor 8, the pickup roller 16 rotates upward, the power of the separation roller 5 is cut off, and the paper feeding operation is stopped. When a predetermined amount is conveyed from the position, the document reaches the document reading unit 1c, and reading of image information by the CIS 13 is started. Thereafter, when the rear end portion of the document S is detected by the first document edge sensor 8, the reading of the image information by the CIS 13 is finished when the predetermined amount is conveyed from the position.

  Next, details of an example paper feed drive system will be described using the configuration shown in FIGS.

  Reference numeral 101 denotes a document separation drive unit, 102 denotes a main drive unit including a single motor 117 to a speed reduction connecting part 117a such as a reduction gear, and 103 denotes a reverse drive unit.

  The document separation drive unit 101 has the following configuration.

  110 is a gear corresponding to the first gear set forth in the claims, 111 is a gear corresponding to the second gear, and is always in mesh with the gear 110. Reference numeral 112 denotes a gear corresponding to the third gear. A swing arm 114 shares the fulcrum 114 a with the center of the gear 110 and shares the fulcrum 114 b with the gear 111. The swing arm 114 is rotatable around a fulcrum 114a. A claw 114c extended further from the vicinity of the fulcrum 114b is provided. 114c is made of an elastic material.

  Reference numeral 115 denotes a latch ring provided coaxially with the gear 112. When the gear 111 approaches the gear 112 in accordance with the rotation of the swing arm 114, the claw 114 c rotates the latch ring 115.

  Further, when the gear 111 is separated from the gear 112, the claw 114 c is elastically deformed and moves while being separated from the latch ring 115.

  Reference numeral 116 denotes a control ring having convex portions 116a and concave portions 116b alternately on the circumference. As shown in FIG. 20 of a detailed view showing a part thereof enlarged, the convex portion 116a is formed with respect to an angle θ formed by the concave portion 116b. The angle between and is 2θ. The latch ring 115 is configured so that the angle at which the claw 114c provided on the swing arm 114 rotates the latch ring 115 by one swing is θ.

  A protrusion 114d protruding in the direction of the control ring 116 is provided in the vicinity of the fulcrum 114b of the swing arm 114. When the protrusion 114d engages with the recess 116b of the control ring 116, the second gear 111 and the third gear 112 are provided. Are engaged, and the power of the first gear 110 is transmitted to the third gear 112.

  Further, when the protrusion 114d contacts the convex portion 116a of the control ring 116, the first gear 110 and the third gear 112 have a long inter-axis distance, so that the gear does not mesh and the power of the first gear 110 is It is not transmitted to the third gear 112.

  Next, the operation will be described with reference to FIGS.

  Since the gear 110 is on a drive train such as a reduction gear mechanism connected to the motor 117, the swing direction of the swing arm 114 is synchronized with the rotation direction of the motor 117. That is, when the motor 117 rotates in the A direction in FIG. 15, the swing arm 114 moves in the A ′ direction, and when the motor 117 rotates in the B direction in FIG. Move in the ′ direction.

  When the swing arm 114 moves in the A ′ direction, as shown in FIG. 17, the claw 114 c rotates the control ring 116 by an angle θ, and switches the phase of the convex portion 116 a and the concave portion 116 b with respect to the protruding portion 114 d.

  A slight brake is applied to the control ring 116 by an elastic member 125 for preventing reverse rotation, and when the swing arm 114 moves in the C ′ direction, the control ring 116 does not rotate and maintains its phase.

  The latch ring 115 and the control ring 116 are integrally formed, and are coaxial with the gear 112 but independent of rotation.

  The pickup arm 16 is connected to the tip of the gear 112 via a clutch spring 118.

  When the motor 117 rotates in the direction B and the recess 116b of the control ring 116 is in a phase that engages with the projection 114d, the gear 111 and the gear 112 are engaged with each other, and the pickup arm 16 rotates downward to feed the document. I do.

  In FIG. 16, reference numeral 119 denotes a lever provided on the document conveying path 14, which rotates when the leading edge of the document S collides, operates the link 120 and pushes the swing arm 114 in the C 'direction.

  At this time, the engagement of the second gear 111 and the third gear 112 is disengaged, the drive transmission to the pickup roller 10 is stopped, and the spring 119 is picked up while the pucker roller 10 is rotated according to the original by the clutch spring 118. The arm 16 is rotated upward, and the pickup roller 10 is separated from the surface of the document S.

  In FIG. 17, in this state, the conveyance roller 7 remains rotating in the D direction, and after the document S passes the lever 119, the link 120 is returned to the initial position by the spring 121. Since the motor 117 continues to rotate in the A direction, the swing arm 114 receives the rotation of the motor 117 in the A direction and rotates the control ring 116 by an angle θ. However, at this time, since the convex portion 116a of the control ring 116 has a size of 2θ, the protruding portion 114d contacts the convex portion 116a, and the state in which the paper feeding operation of the pickup arm 16 is stopped is continued.

  In FIG. 18, after the document reading operation is completed, when the motor 114 starts to reverse to reverse the document S (direction B), the swing arm 114 rotates in the C ′ direction away from the third gear 112. .

  Since the second gear 111 and the third gear 112 do not mesh with each other, the pick-up roller 10 stops rotating, and the pickup arm 16 is pulled by the spring 119 to stop the document feeding operation.

  Even if the swing arm 114 moves in the C ′ direction, the control ring 116 remains stopped due to the engagement of the elastic member 125 for preventing reverse rotation and the latch ring 115.

  In FIG. 19, when the document S is turned upside down by the reversing roller 23 and the motor 117 rotates forward (direction A) again, the swing arm 114 moves the second gear 111 in the third gear 112 direction. Since the claw 114c operates the latch ring 115 to rotate the control ring 116 by an angle θ, the projection 116a with respect to the projection 114d and the projection 116a of the control ring 116 come into contact with each other, and the driving force of the motor 117 is driven by the pickup roller 10. Not transmitted to.

  In FIG. 14, the reversing unit 103 is detachable between a gear 126 rotated by a belt 128 and a gear 126a via a small pulley 127 interlocked with the speed reduction connecting unit 117a. The second paper discharge roller 35 a is controlled by a motor 117.

  The gear 122 is also engaged with the one-way gear 124 via the idler gear 129 and the gear 123 having a clutch action in a direction different from that of the idler gear. One-way state can be maintained.

  In FIG. 14, reference numerals 130, 140, and 141 denote belts stretched around the conveying roller 7, the double-sided discharge roller 35a, and the reversing roller 23, respectively. The attachment / detachment separation position with 1b is shown.

  Next, a series of operations for double-sided image reading according to the present invention will be described below with reference to the timing chart of FIG.

  (S1.) Document presence sensor 6 detects the presence of document S.

Detailed view: Fig. 5
(S2.) After pressing the start key (not shown), the motor 117 rotates, and the pickup arm 16 contacts the document S in the direction of the arrow shown while the pickup roller 10 rotates. The separation roller 5 also rotates in the direction of the arrow shown in the figure, and is separated and conveyed one by one. The transport roller 7, the discharge roller pair 11a and 11b, the reverse roller 23, and the double-sided discharge roller pair 35a and 35b simultaneously start to rotate in the directions of the arrows shown in the drawing.

Detailed view: FIGS. 6 and 15
(S3.) The conveyance roller 7 conveys the document S in the direction of the first document edge sensor 8. When the leading edge of the original is applied to the lever 119 on the way, the pickup roller 16 is released by the action of the control ring 116, and the paper feeding operation is stopped.

Detailed view: FIG. 7, FIG. 16, FIG.
(S4.) After the first document edge sensor 8 detects the leading edge of the document, after a predetermined time has elapsed, the CIS 13 starts scanning the document, and the link 120 is restored when the trailing edge of the document exits the lever 119. The swing arm 114 moves in the direction of the third gear 112, but the control ring 116 rotates θ and the projection 114 d and the projection 116 a are joined, and the power of the first gear 111 is transferred to the third gear 112. I don't get it.

  (S5.) The document S is nipped between the pair of discharge rollers 11a and 11b, the leading edge of the document S is detected by the reverse sensor 22, and the trailing edge of the document S passes through the first document edge sensor 8 and is turned off. The scanning of the CIS 13 is finished after the elapse of a predetermined time (end of scanning of the original S surface).

  (S6.) The reversing sensor 22 is turned off after passing the trailing edge of the document S, and after a predetermined time has elapsed, the motor 117 is stopped and all driving is stopped.

Detailed view: FIG. 8, FIG.
(S7.) The motor 117 rotates in the reverse direction, and the conveying roller 7, the discharge roller pair 11a, 11b, and the double-sided discharge roller pair 35a, 35b simultaneously start to rotate in the directions indicated by the arrows. The reverse roller 23 starts to rotate without changing the direction of rotation by the gear trains 122 to 124 having a plurality of one-way clutches.

  As the motor 114 rotates backward (rotation in direction B), the swing arm 114 is displaced to a position away from the control ring 116 (FIG. 18). The document S travels in the direction of the reverse path 32, makes a U-turn, and enters again from the opening below the backup roller 23b toward the image reading unit. At this time, the paper discharge flapper 37 moves in the direction of the arrow shown in the figure, and controls the paper path of the document S.

  When the rear end of the document S is moved between the reading glass 12 and the transport roller 7, the document to be image-read is transported while passing by the document itself below the transport roller 7.

In the present embodiment, the following numerical formula is satisfied.
(Length of document S) <(opposite roller 7d to paper path 32 to reversing roller 23 to second document edge sensor 29)
By doing so, all the originals are accommodated in the reversing path and are not discharged outside the apparatus.

  In addition, as will be described in detail next in S8, it is possible to configure a single drive source for the reversing roller 23 and the conveying roller 7.

Detailed view: FIGS.
(S8.) Before the second document edge sensor 29 detects the leading edge of the document, the motor switches to normal rotation, and the transport roller 7, the single-sided paper discharge roller 11a, and the double-sided paper discharge roller 35a rotate in the directions indicated by the arrows. Begin. Further, the back side information of the document S is scanned by the CIS 13.

Detailed view: Fig. 11
(S9.) After the second document edge sensor 29 detects the passage of the trailing edge of the document S, the scanning of the document S is finished after a predetermined time has elapsed (the reading of the back surface of the document S is completed).

  (S10.) After the trailing edge of the document passes through the reversing sensor 22 and the sensor is turned off, the sheet discharge flapper 37 moves in the direction of the arrow shown in the figure, and the document S is moved to the second document discharge path 33. Control the paper path. The motor starts to reverse again, and the conveyance roller 7, the discharge roller pair 11a, 11b, and the double-sided discharge roller pair 35a, 35b rotate in the directions indicated by the arrows, respectively.

Detailed view: FIG.
(S11.) The document S is sandwiched between the pair of double-sided paper discharge rollers 35a and 35b and is discharged onto the double-sided paper discharge tray 36 with the surface of the document facing downward.

Detailed view: FIGS. 14 and 15
(S12.) The trailing edge of the document S passes through the reversal sensor 22, and after the predetermined time has elapsed after the sensor is turned off, the document S is discharged and the motor rotates forward again. The conveyance roller 7, the discharge roller pair 11a, 11b, and the double-sided discharge roller pair 35a, 35b rotate forward, and the pickup roller 10 rotates downward to convey the next document S (that is, the same situation as S1). ).

  As described above, the rotation direction of the motor 117 is switched four times in order to read both sides of one sheet of paper. However, since the feeding operation can be performed only once, it is necessary to use a plurality of motors and electromagnetic clutches. Therefore, it is possible to provide a double-sided document feeder.

In addition, the ratio of the angle formed by the convex part 116a and the concave part 116b of the control ring 116 is 2θ: θ is 2: 1 (= K: 1), and the number of switching of the motor rotation direction is N (= 4). ,
N / 2 ≧ K, that is, 4/2 ≧ 2, is a condition for establishing this configuration.

1 is a perspective view of a double-sided image reading apparatus according to the present invention. Sectional view of the double-sided image reading apparatus of the present invention 2 is a perspective view of the double-sided image reading apparatus of the present invention. Double-sided reading operation sequence diagram of the double-sided image reading apparatus of the present invention Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Detailed operation diagram supplementing FIG. Figure showing a conventional example Figure showing a conventional example Figure showing a conventional example

Explanation of symbols

1 Document feeder (equivalent to document feeder)
1a Document feeder main body 1b Document reversing unit (equivalent to document reversing and conveying means)
1c Image reading unit 2 Document placement table 3 Document discharge table 4a, 4b Slider 5 Separation roller (corresponding to document separation means)
6 Document presence sensor 7 Transport roller 8 Document edge sensor 9 Document stopper 10 Pickup roller (corresponding to document separation means)
11, 11b Discharge roller pair 12 Reading glass (corresponding to document reading means)
13 Contact image sensor (equivalent to document reading means)
15 Separation pad 16 Pickup arm (equivalent to document separation means)
21 Lower guide frame 22 Reversing sensor 23 Reversing roller (corresponding to document reversing and conveying means)
26, 27 Inner / outer periphery guide 29 Second document edge sensor 35a, 35b Double-sided discharge roller pair (corresponding to document discharge means)
36 Paper discharge tray 101 Document separation drive unit (corresponding to document separation means)
110 First gear 111 Second gear 112 Third gear 114 Swing arm 114d Protrusion 115 Latch ring 116 Control ring 116a Convex 116b Concave 117 Motor 118 Clutch spring 119 Lever 120 Link 121 Return spring S Original

Claims (5)

In a double-sided image reading apparatus comprising: an original conveying mechanism comprising a sheet-like original conveying means and an original discharging means; an original reversing and conveying mechanism comprising a reverse conveying means for reversing a sheet-like original for double-sided reading; and a reading means. And
The document conveying mechanism and the document reversing and conveying mechanism are connected to a single motor, and the document separating means is provided in the document conveying mechanism. A double-sided image reading apparatus characterized by performing a document separation operation. There is rocking means for pivotally connecting the center axis of the second gear with the center of the first gear for operating the document separating means as a fulcrum, and the power of the first gear via the second gear. Is a drive train that transmits to the third gear, the swinging means can stop at two positions according to the rotation direction of the first gear,
When the first gear rotates in the first direction, the swinging means moves to the first position and the second gear moves away from the third gear;
When the first gear rotates in the direction opposite to the first direction, the swinging means moves to the second position, and the second gear and the third gear can be connected at the second position. The double-sided image reading apparatus according to claim 1, further comprising a gear separation unit that can set two states in an incapable state.   The connecting / separating means for the second gear and the third gear includes a convex portion that keeps the distance between the shafts of the second gear and the third gear so that the gears do not mesh with each other, and the second gear and the third gear. Latch means that alternately has recesses on the circumference that maintain the distance between the gears and the gears in mesh with each other, and that rotates in one direction and stops at a predetermined angle, and does not rotate in the reverse direction. The double-sided image reading apparatus according to claim 1, further comprising: When the ratio of the angle formed by one convex portion and one concave portion provided on the ring is K: 1,
N / 2 ≧ K between N and N for the number of rotations of the motor that switches once every N times (even number of N ≧ 4)
The double-sided image reading apparatus according to claim 1, wherein the relationship is established.   The double-sided image reading apparatus according to claim 1, wherein the motor switching number N is four.

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