JP2014223962A - Sheet transfer device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sheet transfer device which prevents a sheet loading table from excessively moving up and thereby eliminates the possibility of damages of sheets and the sheet transfer device.SOLUTION: A sheet transfer device includes: a sheet loading table 3 where a sheet to be transferred is loaded; a movable mechanism for moving up or down a part of or an entire part of the sheet loading table 3 to a proper position; and a driving source 105 which drives the movable mechanism. The sheet transfer device includes: a sensor part 500 which detects abnormal rise of the sheet transfer table 3; and an interlock switch 502 which is connected with a point between the driving source 105 and a power source and is operated by a detection signal from the sensor part 500 to stop the power supply to the driving source 105.

Description

  The present invention relates to a sheet conveying apparatus.

  As an apparatus that stacks one or more original sheets and feeds them one by one sequentially, there is an automatic document feeder (Auto Document Feeder: ADF) mounted on a copying machine, for example. In ADF, a movable sheet stacking table mechanism in which a part (bottom plate) of a sheet stacking table for stacking documents is moved up and down is already known. In this sheet stacking table mechanism, the sheet stacking table is adjusted to a proper height position for separating and feeding sheets by the vertical movement of the sheet stacking table.

  However, in the conventional movable sheet stacking table mechanism, there is a possibility that the sheet stacking table is excessively raised because the exact height position of the document is unknown. Alternatively, there is a case where software control fails while the sheet stacking table is rising, and there is no way to execute processing for stopping the sheet stacking table from rising. In such a case, a force is continuously applied in the direction of raising the sheet stacking table, and there is a possibility that the upper surface of the sheet feeding unit of the sheet feeding device or the sheet stacking table is damaged.

  Patent Document 1 discloses a mechanism in which a plurality of sensors for detecting the position are installed in the middle of the vertical movement area of the sheet stacking table for the purpose of precise control of the vertical movement of the bottom plate.

  However, with this mechanism, since the exact height position of the top surface of the sheet is unknown, there is a possibility that the sheet stacking table may be raised too much, and when the software control is abnormal, the sheet stacking The problem that there is no way to stop the table rise has not been solved.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet conveying apparatus that can eliminate the possibility of damage to a sheet and the sheet conveying apparatus by preventing the sheet stacking table from being raised too much.

In order to solve the above-described problem, the invention according to claim 1
A sheet transport having a sheet stacking table for stacking sheets to be transported, a movable mechanism for moving a part or all of the sheet stacking table up and down to an appropriate position, and a drive source for driving the movable mechanism. In the device
A sensor unit for detecting an abnormal rise of the sheet stacking table;
An interlock switch connected between the drive source and a power source, and operated by a detection signal from the sensor unit to stop the power supply to the drive source;
It is provided with.

  According to the present invention, it is possible to prevent the sheet and the sheet conveying apparatus from being damaged due to excessive lifting of the sheet stacking table.

1 is a schematic cross-sectional view of a sheet-through ADF in a copying machine using a sheet conveying apparatus according to an embodiment of the present invention. FIG. 3 is a control block diagram in a copying machine using a sheet conveying apparatus according to an embodiment of the present invention. It is explanatory drawing which shows the principal part in the sheet conveying apparatus which concerns on one embodiment of this invention. It is a perspective view which shows the principal part in the sheet conveying apparatus which concerns on one embodiment of this invention. FIG. 3 is a circuit diagram illustrating a main part of the sheet conveying apparatus according to the embodiment of the present invention. It is explanatory drawing which shows the principal part in the sheet conveying apparatus which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, a case where the sheet conveying apparatus according to an embodiment of the present invention is applied to a sheet-through automatic document feeder (ADF) will be described. An ADF is an apparatus that scans an image while conveying a document to be read to a fixed reading device unit at a predetermined speed in a copying machine, which is an electrophotographic image forming apparatus, such as an image reading unit or a scanner machine. Used in the reading unit of the image reading apparatus.

  FIG. 1 is a schematic sectional view of a sheet-through ADF in a copying machine using a sheet conveying apparatus according to an embodiment of the present invention, and FIG. 2 uses the sheet conveying apparatus according to an embodiment of the present invention. FIG. 3 is a control block diagram in a conventional copying machine.

  As shown in FIG. 1, the ADF includes a document setting unit A, a separation feeding unit B, a registration unit C, a turn unit D, a first reading conveyance unit E, a second reading conveyance unit F, and a stack unit H. Yes. The document setting portion A is a portion where a read document bundle is set. The separation feeding unit B is a part that separates and feeds originals one by one from the original bundle set in the original setting unit A. The registration unit C is a part that performs a primary abutting alignment of the document fed from the separation feeding unit B and a function of pulling out and transporting the document after alignment. The turn portion D is a portion that turns the original conveyed from the resist portion C and conveys the original surface toward the reading side (downward). The first reading / conveying unit E is a part for reading the surface image of the document conveyed from the turn unit D from below the contact glass. The second reading / conveying unit F is a part that reads the back side image of the document after being read by the first reading / conveying unit E. The paper discharge unit G is a portion that discharges the original, which has been read on both sides by the first reading conveyance unit E and the second reading conveyance unit F, to the outside of the apparatus. The stack part H is a part for stacking and holding the originals after the reading from the paper discharge part G is completed.

  As shown in FIG. 2, the ADF further includes various sensors, a drive unit that drives the conveyance operation, and a controller 100 that controls a series of operations of the ADF including the drive unit. . Various sensors include a document set sensor 5, a bottom plate home position sensor 6, a table proper position sensor 8, a butting sensor 11, a document width sensor 13, a reading entrance sensor 15, a registration sensor 17, a paper discharge sensor, and separation sensors S1 to S3. Become. The driving unit includes a pickup lifting / lowering motor 101, a paper feeding motor 102, a reading motor 103, a paper discharging motor 104, a bottom plate raising motor 105, a pull-out motor 113, a reading inlet motor 114, and an intermediate conveyance motor 115. The controller 100 is connected to the main body control unit 111 of the copying machine via the I / F 107. An operation unit 108 for performing various input operations and operation instructions is connected to the main body control unit 111 through the I / F 106 and image data read by the second reading unit 25 of the second reading unit F is supplied. Is done.

  In the document setting unit A, a document bundle 1 to be read is set on a document table 2 including a movable document table 3 as a sheet stacking table with a document surface facing upward. Further, with respect to the width direction of the document bundle 1, positioning in a direction perpendicular to the conveyance direction is performed by a side guide (not shown). The set position of the document is detected by the set filler 4 and the set sensor 5, and a detection signal is transmitted to the main body control unit 111 via the I / F 107. Further, an outline of the length in the document transport direction is determined by the document length detection sensor 30 or 31 provided on the surface of the document table 2. As the document length detection sensor 30 or 31, a reflection type sensor or an actuator type sensor that can detect even one document is used. Here, it is necessary to arrange a sensor that can determine at least whether the document size is vertical or horizontal.

  The movable document table 3 is configured to be movable up and down in the a direction or the b direction shown in FIG. 1 by using a base plate raising motor 105 and a movable mechanism (not shown) as a fulcrum. When it is detected by the set filler 4 and the set sensor 5 that the original is set, the bottom plate raising motor 105 is rotated forward by the control of the controller 100 so that the uppermost surface of the original bundle comes into contact with the pickup roller 7. The document table 3 is raised.

  The pickup roller 7 operates to move up and down in the c direction or the d direction shown in FIG. The pick-up roller 7 is pushed by the upper surface of the document on the movable document table 3 when the movable document table 3 is lifted and moves in the c direction, and measures the timing for stopping the normal rotation of the bottom plate raising motor 105 by the table proper position sensor 8. ing. When a print key (not shown) is pressed on the operation unit 108, a document feed signal is transmitted from the main body control unit 111 to the controller 100 via the I / F 107. As a result, the pick-up roller 7 rotates the roller by the normal rotation of the paper feed motor 102 and picks up several (ideally one) originals on the original table 2. The rotation direction is a direction in which the uppermost document is conveyed to the sheet feeding port.

  The paper feeding belt 9 is driven in the paper feeding direction by the normal rotation of the paper feeding motor 102, and the reverse roller 10 is driven to rotate in the reverse direction to the paper feeding by the normal rotation of the paper feeding motor 102, and the uppermost document and its uppermost document. The lower document is separated and only the uppermost document can be fed. More specifically, the reverse roller 10 is in contact with the paper feed belt 9 at a predetermined pressure, and rotates in the state of the paper feed belt 9 when it is in direct contact with the paper feed belt 9 or through a single document. Turned counterclockwise. However, the reverse roller 10 is set so that its rotating force is lower than the torque of the torque limiter. For this reason, if two or more originals enter between the paper feeding belt 9 and the reverse roller 10, the reverse roller 10 rotates in the clockwise direction, which is the original driving direction, and pushes back the extra originals. Double feed is prevented.

  The original separated by the action of the paper feeding belt 9 and the reverse roller 10 is further fed by the paper feeding belt 9, and the leading edge is detected by the abutting sensor 11 and further advances to the pull-out roller 12 which stops. bump into. Thereafter, the document is fed a predetermined amount from the detection of the abutting sensor 11 described above. As a result, the paper feed motor 102 is stopped while being pressed against the pull-out roller 12 with a predetermined amount of deflection, whereby the drive of the paper feed belt 9 is stopped. At this time, the pickup raising / lowering motor 101 is rotated to retract the pickup roller 7 from the upper surface of the document, and the document is fed only by the conveying force of the paper feed belt 9. As a result, the leading edge of the document enters the nip between the pair of upper and lower rollers of the pull-out roller 12, and the leading edge is aligned (skew correction).

  The pull-out roller 12 has a skew correction function and is a roller for conveying the skew-corrected document after separation to the intermediate roller 14, and is driven by reverse rotation of the paper feed motor 102. At this time (when the paper feed motor 102 is reversely rotated), the pull-out roller 12 and the intermediate roller 14 are driven, but the pickup roller 7 and the paper feed belt 9 are not driven. A plurality of document width sensors 13 are arranged in the depth direction and detect the size in the width direction perpendicular to the transport direction of the document transported by the pull-out roller 12. The length of the document in the conveyance direction can be detected from the motor pulse by reading the leading edge and the trailing edge of the document with the butting sensor 11.

  When the document is transported from the resist section C to the turn section D by driving the pull-out roller 12 and the intermediate roller 14, the transport speed at the resist section C is set higher than the transport speed at the first reading transport section E. Thus, the processing time for sending the document to the first reading conveyance unit E is shortened.

  When the leading edge of the document is detected by the reading inlet sensor 15, before the leading edge of the document enters the nip between the upper and lower roller pairs of the reading inlet roller 16, deceleration for making the document conveying speed the same as the reading conveying speed is started. The At the same time, the reading motor 103 is driven to rotate forward, and the reading inlet roller 16, the reading outlet roller 23, and the CIS outlet roller 27 are driven. When the leading edge of the document is detected by the registration sensor 17, the document is decelerated over a predetermined conveyance distance, temporarily stopped before the reading position 20, and registered with the main body control unit 111 via the I / F 107. A stop signal is sent. Subsequently, when a reading start signal is received from the main body control unit 111, the document whose registration has been stopped is accelerated and conveyed so as to rise to a predetermined conveying speed until the leading edge of the document reaches the reading position. The At the timing when the leading edge of the document detected by the pulse count of the reading motor 103 reaches the first scanning conveyance unit E, the gate signal indicating the effective image area in the sub-scanning direction on the first surface is sent to the main body control unit 111 after the document. Sent until the end passes through the first reading and conveying unit E.

  In the case of single-sided document reading, the document that has passed through the first reading conveyance unit E is conveyed to the paper discharge unit G through the second reading conveyance unit F. At this time, when the leading edge of the document is detected by the paper discharge sensor 24, the paper discharge motor 104 is driven to rotate forward, and the paper discharge roller 28 rotates counterclockwise. In addition, the discharge motor drive speed is reduced immediately before the trailing edge of the document comes out of the nip between the upper and lower roller pairs of the discharge roller 28 by the discharge motor pulse count from the detection of the leading edge of the document by the discharge sensor 24. Control is performed so that the document discharged onto the paper tray 29 does not jump out.

  In the case of double-sided document reading, the second image reading unit 25 is detected at the timing when the document leading edge reaches the second image reading unit 25 by the pulse count of the reading motor 103 after the paper discharge sensor 24 detects the document leading end. On the other hand, a gate signal is transmitted. This gate signal is a signal indicating an effective image area in the sub-scanning direction from the controller 100 and is transmitted until the trailing edge of the document passes through the second reading conveyance unit F. The second reading roller 26 serves as a reference white part for obtaining shading data in the second image reading unit 25 as well as suppressing the floating of the document in the second image reading unit 25.

  FIG. 3 is a schematic side view of the separation feeding unit B of FIG. 1, and FIG. 4 is a schematic perspective view of the separation feeding unit B. Here, in the separation unit 51 of the separation feeding unit B, a support arm member 52 that pivotally supports the pickup roller 7, a paper feed guide 53, and a light shielding plate 52 a are respectively rotatable about a shaft 54. Is attached. The paper feed guide 53 is urged by an urging spring 53a in a direction in which the original on the movable original table 3 is pressed. The pickup roller 7 attached to the support arm member 52, the paper feed guide 53, and the light shielding plate 52 a are in contact with the original on the movable original table 3 and rotate according to the vertical movement of the movable original table 3. . The light shielding plate 52 a operates the table proper position sensor 8 so as to be turned on or off by blocking the detection light of the table proper position sensor 8 when moving upward together with the pickup roller 7. Thereby, the table appropriate position sensor 8 detects the appropriate position (paper feeding position) of the movable document table 3.

  The movable original table 3 and the light shielding plate 52a are raised by the driving of the bottom plate raising motor 105 under the control of the controller 100, and the position is detected by the table proper position sensor 8 by the light shielding plate 52a. The bottom plate raising motor 105 is stopped by the detection signal from the table proper position sensor 8 that has detected the position. Thereby, the position of the movable document table 3 is adjusted to an appropriate position (paper feeding position).

  Further, when the movable document table 3 is in an abnormal state that continues to rise without stopping at the appropriate position (feeding position) due to an abnormality of the controller 100 or the like, an interface disposed at a position above the table appropriate position sensor 8 is used. The sensor unit 500 of the lock switch mechanism is operated. The sensor unit 500 is, for example, a micro switch having a leaf spring type actuator. When the movable document table 3 continues to rise, the sensor unit 500 is turned on when the actuator is pushed by the raised light shielding plate 52a, and detects an abnormal position above the proper position due to the rise of the sheet stacking table. To do.

  As shown in FIG. 5, the bottom plate raising motor 105 is, for example, a DC motor, and is connected to the drive power source E via a relay contact 502a of a relay switch 502 as an interlock switch of the interlock switch mechanism. The drive coil 502b of the relay switch 502 and the micro switch of the sensor unit 500 are connected in series to the drive power source E.

  In FIG. 5, when the sensor unit 500 is off (open), no current flows through the drive coil 502b of the relay switch 502, so the relay contact 502a is on (closed), and the bottom plate raising motor 105 is It is rotated by power supply from the drive power source E.

  On the other hand, when the sensor unit 500 is turned on (closed), a drive current flows from the drive power source E to the drive coil 502b, so that the relay contact 502a of the relay switch 502 is turned off (open), and the bottom plate raising motor 105 stops. . Accordingly, the abnormal rise of the movable document table 3 is stopped, and the possibility of damage to the document and the separation feeding unit can be eliminated.

  As shown in FIG. 6, the sensor unit 500 of the interlock switch mechanism may be installed above the appropriate position sensor 8 and directly contact the upper surface of the document for detection. Further, a guide unit 501 for guiding the document without turning on the sensor unit 500 when the user sets the document may be provided.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to this, A various deformation | transformation and application are possible. Of course, such modifications and applications are included in the scope of the present invention as long as the configuration of the present invention is provided.

  For example, in the above embodiment, the drive coil 502b of the relay switch 502 of the interlock switch mechanism is connected to the drive power source E of the bottom plate raising motor 105, but may be connected to another power source.

  The sensor unit 500 may be operated by directly contacting the sheet stacking table or the uppermost surface of the sheet on the sheet stacking table.

  In the above-described embodiment, the bottom plate raising motor 105 moves only the movable document table 3 up and down. However, the present invention is not limited to this, and the bottom plate raising motor 105 may be configured to move all the movable document table 3 and the document table 2 up and down. .

2 Document table (sheet stacking table)
3 Movable document table (sheet stacking table)
8 Table proper position sensor 105 Bottom plate raising motor (drive source)
500 Sensor part (micro switch)
501 Guide unit 502 Relay switch (interlock switch)

Japanese Patent Laid-Open No. 11-352608

Claims (5)

A sheet transport having a sheet stacking table for stacking sheets to be transported, a movable mechanism for moving a part or all of the sheet stacking table up and down to an appropriate position, and a drive source for driving the movable mechanism. In the device
A sensor unit for detecting an abnormal rise of the sheet stacking table;
An interlock switch connected between the drive source and a power source, and operated by a detection signal from the sensor unit to stop the power supply to the drive source;
A sheet conveying apparatus comprising: A table proper position sensor for detecting a proper position of the sheet stacking table;
The sheet conveying apparatus according to claim 1, wherein the sensor unit detects an abnormal position above an appropriate position of the sheet stacking table.   3. The sheet conveying apparatus according to claim 1, wherein the driving source is a DC motor. 4. The sheet conveying apparatus according to claim 1, wherein the sensor unit operates by directly contacting the sheet stacking table or an uppermost surface of the sheet on the sheet stacking table. 5. . 5. The guide unit according to claim 1, further comprising: a guide unit that guides the sheet onto the sheet stacking table so that the sheet does not contact the sensor unit when the sheet is stacked on the sheet stacking table. The sheet conveying apparatus according to claim 1.

Images