JP5445249B2 - Automatic document feeder, image reading apparatus, and image forming apparatus - Google Patents

Description

  The present invention relates to an automatic document feeder provided with an open / close cover, an image reading device provided with the automatic document feeder, and an image forming apparatus.

  An automatic document feeder, an image forming apparatus, and the like are provided with an open / close cover, a door, and the like (hereinafter collectively referred to as an open / close cover) for jam processing and maintenance. In general, a lock mechanism is provided that detects a switch or sensor provided on the apparatus main body side when the open / close cover is closed.

  However, in the conventional apparatus, when the opening / closing cover is closed, a state in which the opening / closing cover is not completely closed, that is, a so-called single lock may occur. There is a measure to detect a single lock by attaching sensors to the front and back (front and back) of the opening / closing cover, but new costs are incurred. Although it is possible to prevent a single lock by a mechanical mechanism, there are problems that the number of parts constituting the opening / closing cover increases, the opening / closing cover becomes larger and heavier.

  Japanese Patent Laying-Open No. 2009-198708 (Patent Document 1) discloses an image forming apparatus that uses a cover opening / closing sensor and an interlock switch to improve the detection accuracy of one lock.

  However, conventionally, a technique that combines a cover open / close sensor and an interlock switch has been adopted, and separating the cover open / close sensor and the interlock switch as described in Patent Document 1 (provided separately) This is the same as adding a new sensor for detecting one lock, and the problems of an increase in the number of parts and cost are not solved.

  The present invention solves the above-described problems in an automatic document feeder provided with an open / close cover, and can improve the accuracy of one-lock detection without increasing the number of parts and cost, an image reading device, and image formation It is an object to provide an apparatus.

  According to the present invention, there is provided an automatic document feeder that feeds documents one by one from a bundle of documents set in a document setting section and conveys them to a predetermined reading position according to the present invention. An open / close detecting means for detecting an open / closed state of the open / close cover; and an original set detecting means for detecting an original set on the original setting portion, wherein the open / close detecting means and the original set detecting means And a control unit which is disposed on each side of the opening / closing axis of the opening / closing cover and determines the opening / closing state of the opening / closing cover based on a detection output of the opening / closing detection unit and a detection output of the document set detection unit. It is solved by.

Further, it is preferable that the opening / closing detection means and the document set detection means are respectively disposed in an area where displacement is greatest when the opening / closing cover is twisted.
The open / close detection unit and the document set detection unit each include a detection sensor and a detected member. At least the detected member is provided on the open / close cover, and the detected member of the open / close detection unit and the document Of the detected members of the set detecting means, it is preferable to arrange the detected member having the higher strength on the front side of the apparatus.

Further, it is preferable that the opening / closing detection means is disposed on the back side of the apparatus.
Further, it is preferable that the control means detects the open / close detection means after the output of the document set detection means is turned on.

  In addition, a notification unit that notifies the user of information or warning is provided, and the control unit is configured to detect whether the opening / closing cover is open or not and the jam document based on the detection output of the opening / closing detection unit and the detection output of the document set detection unit. It is preferable to notify the presence or absence of this.

In addition, according to the present invention, the above problem is solved by an image reading apparatus including the automatic document feeder according to any one of claims 1 to 6.
Further, according to the present invention, the above-described problem is solved by an image forming apparatus that includes an image reading device and includes the automatic document feeder according to any one of claims 1 to 6.

  According to the automatic document feeder, the image reading device, and the image forming apparatus of the present invention, it is possible to detect with high accuracy the presence or absence of a single lock of the open / close cover and a jammed document. In addition, the highly accurate detection can be realized without an additional part such as a sensor without increasing the cost.

According to the configuration of the second aspect, high-precision detection can be performed using the twist of the opening / closing cover.
According to the configuration of the third aspect, by disposing the detected member having higher strength on the front side of the apparatus, it is possible to suppress damage to the detected member on the front side where the user frequently pushes in.

  According to the configuration of the fourth aspect, the upper cover is often locked by pushing the user side (the front side of the apparatus), and the lock member far from the user is not engaged and often becomes a single lock. On the other hand, it is possible to reliably detect a single lock by disposing an open / close detection means on the back side of the apparatus that can specify a single lock position.

According to the configuration of the fifth aspect, the power consumption of the entire system can be reduced by limiting the detection timing of the open / close detection means.
According to the configuration of the sixth aspect, the open / close state of the open / close cover and the presence / absence of the jammed document can be notified to the user. In addition, the possibility of machine failure can be reduced.

1 is a cross-sectional configuration diagram illustrating an example of an automatic document feeder according to the present invention. FIG. 6 is a partial perspective view showing a state in which the upper cover of the automatic document feeder is opened. FIG. 3 is a view showing an upper cover without a document in a fully closed state as viewed from the direction A in FIG. 2. It is a figure which shows the one side lock | rock of the upper cover in the apparatus front side seen from the A direction of FIG. It is an enlarged view of the lock part of the apparatus front side. It is a figure which shows the one-side lock | rock of the upper cover in the apparatus back | inner side seen from the A direction of FIG. It is an enlarged view of the lock | rock part of an apparatus back side. FIG. 3 is a diagram illustrating a state when a document is set as viewed from the direction A in FIG. 2. It is an enlarged view when it sees from the B direction of FIG. It is a flowchart which shows the flow from jam generation to a normal use possible state. It is a block diagram which shows the structure of a single-lock detection part. It is a flowchart which shows control of a single lock | rock detection part. 1 is a cross-sectional view illustrating a configuration of a copying apparatus that is an example of an image forming apparatus according to the present invention. It is a schematic diagram explaining the area | region with the largest displacement when an upper cover is twisted.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to the configuration of the present embodiment.
FIG. 1 is a sectional view showing an example of an automatic document feeder according to the present invention. In this figure, an automatic document feeder 1 is attached to an upper part of an image reading device 2 such as a scanner so as to be opened and closed. The image reading device 2 is provided with a slit glass (reading position) 3 on its upper surface, and the automatic document feeder 1 transports the document and passes the document over the slit glass 3 to read the document.

  In the automatic document feeder 1, a single-side mode and a duplex mode can be selected by an instruction from an operation unit (not shown), and the operation of the automatic document feeder 1 is controlled by the set mode. The document 6 is set on the document stacking table 5 in page order with the image surface facing up. The pickup roller 7 is normally on standby with a predetermined interval from the document stacking table 5, and it is detected by the document set detection filler 8 that a document has been set on the document stacking table 5, and on an operation unit (not shown). When the start of reading is instructed, it is controlled so as to descend from the standby position and move to a position in contact with the upper surface of the document 6.

  Next, the feed roller 9 and the reverse roller 10 separate the documents one by one from the top. A separation pad may be used instead of the reverse roller 10. The conveyance path (A) is formed between the guides 11 and 11 a and is a path for conveying the document separated and conveyed by the feed roller of the separation unit onto the slit glass 3. The guide 11 is formed by an upper cover 29, and the upper cover 29 can rotate around the upper cover rotating shaft 33. A conveyance path (b) is formed between the guides 12 and 12 a and is a path for moving the document conveyed through the slit glass to the paper discharge port 13. Reference numeral 14 denotes a paper discharge tray for stacking the documents discharged from the document discharge port 13. The switchback conveying path (c) is formed between the guides 16 and 16a, 16a provided at the lower part of the document stacking table 5 and above the document tray 14, and the branching claw, and the sheet discharge port. The document ejected from 13 is switched back and guided again from the rear end of the document to the transport path (A).

  The branching claw 17 is provided above the document tray 14, and by switching to the dotted line position, the document ejected from the ejection port 13 is guided to the switchback path (c), and the document is introduced into the switchback path (c). Then, by switching to the solid line position, the document switched back in the switchback conveyance path (c) is guided from the rear end to the conveyance path (d). The conveyance path (d) is formed between the guides 18 and 18a, is joined with the conveyance path (a), and is a path for conveying the switched-back document to the reading position again.

  The reversing rollers 26 and 26a have means for switching between normal rotation and reverse rotation independently, and the document conveyed to the switchback conveyance path (c) is introduced into the switchback path (c) and then reversely rotated. Then, the document is conveyed to the conveyance path (d). A sensor 28 is arranged between the reading roller and the reading roller to match the leading edge of the document conveyed by the reading roller with the timing of reading start. Each roller is driven by a single drive source (one motor).

The operation of the automatic document feeder 1 configured as described above will be described.
[Single-sided mode]
When a document is set on the document table 5, the document set detection filler is rotated by the document to switch ON / OFF of a transmission sensor (not shown). Whether or not a document is set on the document stacking table 5 by the ON / OFF signal of the document set detection sensor described above when a start key provided on an operation unit (not shown) is pressed in a state where the single-sided mode is set. Is checked. When the document set is detected, the motor rotates forward, the pickup roller 7 descends and is pressed against the document, and the pickup roller 7 rotates clockwise in the drawing to feed the document. The documents fed by the pickup roller are separated one by one by the feed roller 9 and the reverse roller 10 (or separation pad).

  Next, when the leading edge of the document 6 is detected by the sensor 28, a reading start timing is taken, and reading is started in accordance with the leading edge of the document. Further, when the trailing edge of the document is detected by the sensor 28, the reading end timing is taken, and the reading is ended in accordance with the trailing edge of the document. In the single-sided mode, the branching claw is always at the position of the solid line in the figure, so after reading, the paper is discharged from the paper discharge outlet 13 to the paper discharge tray 14 and stacked on the image side. Although the motor is always driven, the sheet interval is formed by setting the linear velocity of the conveying roller 19 faster than the linear velocity of the feed roller 9. When all the originals have been read, the motor reverses and the pickup roller 7 is raised and moved to the standby position.

[Double-sided mode]
When a start key provided on an operation unit (not shown) is pressed in a state where the duplex mode is set, whether or not a document is set on the document stacking table 5 is checked by turning on / off a document set detection sensor. The When the document set is detected, the motor rotates forward, the pickup roller 7 descends and is pressed against the document, and the pickup roller 7 rotates clockwise in the drawing to feed the document. The documents fed by the pickup roller are separated one by one by the feed roller 9 and the reverse roller 10 (or separation pad). Next, when the leading edge of the document 6 is detected by the sensor 28, a reading start timing is taken, and reading is started in accordance with the leading edge of the document. When the tip is detected by the sensor 28, the branching claw is moved to the dotted line position in the figure, and the reverse roller 26 is rotated in the normal rotation direction (clockwise direction in the figure). Further, when the leading edge of the document 6 is detected by the sensor 28, the driving of the feed roller 9 and the pickup roller 7 is released by a clutch or the like, and the next document is kept on standby without being fed. When the trailing edge of the document is detected by the sensor 28, the reading end timing is taken, and the reading is ended in accordance with the trailing edge of the document. Thereafter, the original is conveyed from the paper discharge outlet 13 to the switchback path (C).

  After a certain time T from the sensor 28 (after a time sufficient for the trailing edge of the document to completely pass through the paper discharge port 13), the branching claw is switched to the solid line position in the figure, and the rotation direction of the reverse roller 26 is reversed. (Counterclockwise in the figure), and the document is guided to the conveyance path (d). Next, the document that has entered the conveyance path (d) is sent to the conveyance path (b). When the leading edge of the document is detected by the sensor 28, the reading operation of the back surface of the document 6 is performed in the same manner as the front surface. When the tip is detected by the sensor 28, the branching claw 17 is moved again to the dotted line position in the figure, and the reverse roller 26 is rotated in the forward rotation direction. At this time, the pre-reading roller 20 and the reverse roller 26 rotate in opposite directions, but a torque limiter is provided on the reverse roller shaft so as to follow the pre-reading roller.

  When the reading operation on the back surface is completed, it is switched back again and sent to the transport path (A). At this time, the reading operation is not performed. Even if the leading edge of the document is detected by the sensor 28, the document is discharged onto the discharge tray 14 with the surface facing down by setting the branching claw to the solid line position. When the document passing sensor 8 detects the original at the time when the third passage of the rear end of the original is detected by the sensor 28, the next original feeding operation is performed. Thereafter, the above-described operation is repeated until the document set detection sensor no longer detects the document, whereby the double-sided document processing for the document on the document stacking table 5 is completed.

FIG. 2 is a partial perspective view showing a state in which the upper cover 29 forming the guide 11 of the automatic document feeder 1 is opened.
The upper cover 29 is assembled to the side plate 34 a and the side plate 34 b so as to be rotatable about the upper cover rotating shaft 33. The upper cover 29 is opened when a jam occurs in the transport path (A), and is closed after the jam processing is completed. When closed, the lock portions 31a and 31b provided on the upper cover 29 are engaged with the locked portions 32a and 32b, respectively, and the upper cover 29 is locked.

  At this time, even if a pair of locking members are engaged, the other pair of locking members may not be engaged. This state is the direction lock. The single lock occurs when the torsional strength of the upper cover 29 is weak with respect to the force required to engage the lock member. In the conventional apparatus, when the user does not notice the single lock on the upper cover, the document feeder cannot detect the single lock, and the user operates the automatic document feeder, the roller pressure is applied by the upper cover. When managing, skew or jam may occur. Similarly, skew and jam occur when the automatic document feeder operates when a jam document remains.

On the other hand, the present invention increases the accuracy of detecting the presence or absence of the single lock and jammed document described above without any additional components.
Specifically, an upper cover opening / closing detection sensor 30 serving as an opening / closing detection unit is provided on one side in the direction of the upper cover rotation axis, and a document set detection sensor 38 serving as a document set detection unit is provided on the other side. Detected portions (fillers) 30a and 38a that are detected by respective sensors are provided at both end portions of the tip, and by detecting the ON / OFF state of the sensors 30 and 38, the state of the upper cover in the rotation axis direction, that is, It can be detected with high accuracy whether the lock portions 31a and 31b are engaged with the locked portions 32a and 32b, respectively. The detected portion 38 a is provided at the end of the rotation shaft of the document set detection filler 8 and rotates together with the document set detection filler 8. The sensor 30 and the sensor 38 both use photo interrupters in this example.

  In the above configuration, the positions of the upper cover open / close detection sensor 30 and the document set detection sensor 38 are not limited. However, it is desirable that the upper cover 29 is installed in a region having the largest displacement when the upper cover 29 is twisted, that is, at the end portion in the direction of the rotation axis farthest from the upper cover rotation shaft 33. In addition, it is desirable to install the detected portion 38a and the detected portion 30a (upper cover opening / closing filler) having higher strength on the user side (front side of the apparatus).

  Here, the region having the largest displacement when the upper cover 29 is twisted will be described with reference to FIG. In FIG. 14, the outer shape of the cover when the upper cover 29 is closed is indicated by a rectangle (thick solid line). Since the cover rotation shaft 33 is provided at the base portion of the cover, the rotation shaft direction is a direction as indicated by a one-dot chain line. On the other hand, the upper cover open / close detection sensor 30 and the document set detection sensor 38 are arranged in the vicinity of each square side end (end in the direction of the rotation axis) away from the rotation shaft 33, respectively. 38 is positioned at the corner of the square away from the rotation shaft 33, and the rotation shaft 33 on the left side of the figure and the document set detection sensor 38 are arranged on the diagonal of the rectangle, and the rotation shaft 33 on the right side and the upper cover open / close detection The sensors 30 are arranged on another diagonal line of the quadrangle, and each sensor is installed in a region where the displacement is greatest when the upper cover 29 is twisted. Thereby, highly accurate detection is possible using the twist of the upper cover 29. Even when the cover is not square, it may be arranged in a region where the displacement is greatest when twisted.

  FIG. 3 is a view showing the upper cover 29 without a document in the fully closed state as viewed from the direction A in FIG. The lock portions 31a and 31b are engaged with the locked portion, the detected portion 30a shields the upper cover opening / closing sensor 30, and the detected portion 38a shields the original set detection sensor 38.

  4 is a view showing a single lock when the lock portion 31a on the upper cover opening / closing sensor 30 side is not engaged, as viewed from the direction A in FIG. 2, and FIG. 5 is an enlarged view of the lock portion 31a. As can be seen from FIG. 5, in the one-lock state in which the lock portion 31a is not completely engaged with the locked portion 32a, the detected portion 30a of the upper cover cannot shield the upper cover open / close sensor 30 from light. It is possible to detect that it is locked.

  6 is a view showing a single lock when the lock portion 31b on the side of the document set detection sensor 38 is not engaged, as seen from the direction A in FIG. 2, and FIG. 7 is an enlarged view of the lock portion 31b. As can be seen from FIG. 7, in the one-lock state in which the lock portion 31b is not completely engaged with the locked portion 32b, the detected portion 38a does not shield the document set detection sensor 38 from light. Therefore, it can be detected that either a document set or a single lock has occurred.

  FIG. 8 is a diagram showing a state when the document is set as viewed from the A direction in FIG. 2, and FIG. 9 is an enlarged view when viewed from the B direction (described in FIG. 8). When the document 6 is set, the document set detection filler 8 rotates, and the detected portion 38a also rotates to transmit the document set detection sensor 38 (sensor OFF).

FIG. 10 is a flowchart showing the relationship between the user operation from the occurrence of a jam to the normal usable state and the document set detection sensor 38 and the upper cover open / close detection sensor 30.
In the flowchart of FIG. 10, first, a jam occurs (S1), the user opens the upper cover 29 (S2), and the jammed document is removed (S3). At this time, both the document set detection sensor 38 and the upper cover open / close detection sensor 30 are OFF. After the jam original is removed, the upper cover is locked (S4). Thereafter, first, it is detected whether the document set detection sensor 38 changes from OFF to ON (S5). When the sensor 38 changes from OFF to ON, the jammed document is removed and the front lock member of the upper cover 29 is engaged. However, if the change of the document detection sensor 38 from OFF to ON is not detected, the jammed document remains or the upper cover 29 is open, so the process returns from S6 to S3, and the user starts again after removing the jammed document. . Next, it is detected whether or not the upper cover open / close detection sensor 30 has been turned ON after the document set detection sensor 38 has been turned ON (S7). When the upper cover open / close detection sensor 30 is turned ON, the jammed document is removed and the upper cover 29 is also completely closed. Therefore, the process proceeds from S8 to S9, and the original can be used normally by setting the document again. is there. However, when the upper cover open / close detection sensor 30 remains OFF, the lock member on the rear side of the upper cover 29 is not engaged (S10). Therefore, the process returns to S4, and the user uses the automatic document feeder after opening and closing the upper cover 29 again.

FIG. 11 is a block diagram illustrating a configuration of a single lock detection unit in the automatic document feeder 1 of the present embodiment.
As shown in this figure, the operation panel 51 is connected to the control unit 50, and operation signals and data for display are transmitted to and received from the control unit 50. The control unit 50 also outputs a control signal to the drive unit 51 of the automatic document feeder. The sensor outputs of the document set detection sensor 38 and the upper cover open / close detection sensor 30 are sent to the control unit 50. The control unit 50 controls the drive unit 52 based on ON / OFF of the document set detection sensor 38 and the upper cover open / close detection sensor 30 and information input by the user through the operation panel 51. During jam processing, the controller 50 does not always detect whether the document set detection sensor 38 and the upper cover open / close detection sensor 30 are ON / OFF, but the document set detection sensor 38 is ON as described with reference to the flowchart of FIG. After the change is detected, the upper cover open / close detection sensor 30 is turned ON / OFF. In this way, by limiting the timing for detecting ON / OFF of the upper cover open / close detection sensor 30, the power consumption of the entire system can be reduced.

FIG. 12 is a flowchart showing the control of the single lock detector when detecting a single lock as described in FIGS.
As shown in FIG. 12, the process starts from the state where the upper cover is opened, that is, the document set detection sensor 38 and the upper cover opening / closing sensor 30 are both OFF (transmitted) (S11). First, ON / OFF determination of the document set detection sensor 38 is performed (S12). In the case of OFF, an error message is output to the operation panel 51 so as to open the upper cover 29 again and remove the jammed document (S13), thereby indicating the next operation to be performed to the user. After notifying the error message, the original set detection sensor 38 is again turned ON / OFF (S12). If it is ON, the upper cover opening / closing sensor 30 is turned ON / OFF (S14).

  When the upper cover opening / closing sensor 30 is OFF, since the upper cover locking portion 31a (the locking portion on the upper cover opening / closing sensor 30 side) is not completely locked, the upper cover is one-side locked. Therefore, an error message is issued on the operation panel so as to open and close the upper cover again (S15). Alternatively, since it is clear that the lock portion 31a is incompletely locked, an error message that pushes around the lock portion 31a may be used.

  In many cases, the upper cover is locked by pushing the user side (the front side of the apparatus). For this reason, a lock member far from the user is not engaged and the upper cover is often single-locked. For this reason, it is desirable to provide the upper cover opening / closing sensor 30 and the detected portion 30a that can specify the one-lock position on the side away from the user (the back side of the apparatus).

  When the upper cover open / close detection sensor 30 is ON, the upper cover is in a completely closed state, and the operation panel 51 informs the user that the automatic document feeder can be used (S16). Then, after the document is reset, the automatic document feeder can be used normally (S17).

  Table 1 below is a table showing the upper cover state according to the combination of sensor outputs of the document set detection sensor 38 and the upper cover open / close detection sensor 30, and the presence or absence of a jammed document in the separation unit. In this table, the sensor “ON” means that the sensor output is at a high level output voltage, that is, the sensor is shielded from light. Further, the document set detection sensor 38 side is the front side of the automatic document feeder.

  In Table 1, no. As shown in FIG. 1, when both the upper cover open / close detection sensor 30 and the document set detection sensor 38 are turned on, the upper cover 29 is closed and there is no jammed document. Therefore, after that, the user can set the document on the sheet feeding unit and use it normally.

  On the other hand, no. 2-No. 7, the combination of ON / OFF of the upper cover open / close detection sensor 30 and the document set detection sensor 38 determines the state of the upper cover 29 and the presence / absence of a jammed document. Cannot be distinguished. However, since either one of them causes a malfunction of the automatic document feeder, it is meaningful for the user to be able to detect the presence or absence of a single lock and the presence or absence of a JAM document.

  When an operation panel is provided in the automatic document feeder or the image forming apparatus, a warning can be given to the user through an error message or the like. When there is no operation panel (or there is no display means such as a monitor on the operation panel), a warning method such as turning on a warning lamp or generating a warning sound from a speaker is also possible. Here, a display unit such as a monitor, a warning lamp, a speaker, and the like are notification units that notify the user of information and warnings. Then, according to the flowchart of FIG. 10, by warning (notifying) so that the user can work, the machine can be operated in the one-lock state without adding a part and adding a lock mechanism or adding a sensor. Prevention, improving user safety and reducing the possibility of machine failure.

Finally, an example of an image forming apparatus to which the present invention is applied will be described.
FIG. 13 is a cross-sectional view showing a configuration of a copying apparatus which is an example of an image forming apparatus according to the present invention. The copying apparatus shown in FIG. 1 includes an image forming unit 110, a paper feeding unit 120, an image reading unit 130, and an automatic document feeder 140. An in-body paper discharge unit 150 is provided between the image forming unit 110 and the image reading unit 130.

  The image forming unit 110 employs a tandem method and can form a full-color image, and four image forming units 101 (a, b, c, d) are arranged in a substantially central part. Each of the image forming units 101 (a, b, c, d) is a unit for forming an image with each color toner of yellow, magenta, cyan, and black, and is arranged in parallel along the lower side running side of the intermediate transfer belt 107. Has been. The intermediate transfer belt 107 wound around the support rollers 108a and 108b is driven to run counterclockwise in the drawing. A cleaning unit 109 for cleaning the intermediate transfer belt 107 is disposed outside the left support roller 108a. Above the intermediate transfer belt 107, toner bottles 113 (a, b, c, d) containing respective color toners supplied to the developing device of the image forming unit are arranged.

  Each image forming unit 101 (a, b, c, d) has the same configuration except for the color of the toner to be handled. In the following description, the suffixes a, b, c, d are omitted. The image forming unit 101 includes a photosensitive drum 102 as an image carrier. Around the photosensitive drum 102, a charging unit 103, a developing device 104, a cleaning unit 105, and the like are arranged. Further, a transfer as a primary transfer unit is provided inside the intermediate transfer belt 107 so as to face each photosensitive drum 102. A roller 106 is provided. Each image forming unit 101 is attachable to and detachable from the apparatus main body as a process cartridge.

  Below the four image forming units 101, an optical writing device 100 is provided. The optical writing device 100 irradiates the surface of the photosensitive drum 102 of each color image forming unit with laser light as scanning light.

  A lower part of the image forming unit 110 is a paper feeding unit 120, and a paper feeding tray 121 on which paper is stacked is provided. A paper feed roller 122 is provided on the right side of the paper feed tray 121 and feeds the sheets stacked on the paper feed tray one by one.

  A transport roller pair 123 and a registration roller 124 are provided on the downstream side of the paper feed roller 122 in the paper transport direction. Further, a transfer roller 111 as a secondary transfer unit is provided above the registration roller 124 so as to be opposed to the belt support roller 108b which is a transfer counter roller, thereby forming a secondary transfer portion.

  A fixing device 112 is provided above the secondary transfer unit. The fixing device 112 fixes the sheet on which the unfixed toner image is transferred in the secondary transfer unit by heating and pressurizing the sheet. A paper discharge roller 114 is provided above the fixing device 112, and discharges the fixed paper onto the paper discharge tray 115 of the in-body paper discharge unit 150.

  A reading unit 130 is provided above the image forming unit 110 with the in-body sheet discharge unit 150 interposed therebetween. The reading unit 130 reads and scans a document (not shown) placed on the contact glass 131, a first traveling body 132 including a document illumination light source and a first mirror, a second mirror, and a first mirror. A second traveling body 133 having three mirrors is provided. The image information of the original scanned by the first traveling body 132 and the second traveling body 133 is read as an image signal into the CCD 135 installed behind the lens 134, and the read image signal is digitized. Image processing is performed. Based on the image-processed signal, the light source of the optical scanning device 100 emits irradiation light, and the irradiation light scans the surface of the photoconductor 102, thereby forming a latent image on the surface of the photoconductor 102.

  An automatic document feeder (ADF) 140 is mounted on the reading unit 130. The ADF 140 feeds the documents set on the document tray one by one, scans the first traveling body 132 and the second traveling body 133 stopped at predetermined positions in the reading unit 130 while conveying the documents, The original image is read. The basic configuration of the automatic document feeder 140 is the same as that of the automatic document feeder 1 described above, and includes an upper cover 29. The detection of the one-lock on the upper cover is the same as that described with reference to the automatic document feeder 1, and the description thereof is omitted because it is redundant.

An image forming operation in the copying apparatus configured as described above will be briefly described.
The photosensitive drum 102 of the image forming unit 101 is rotated in the clockwise direction in the drawing by a driving unit (not shown), and the surface of the photosensitive drum 102 is uniformly charged to a predetermined polarity by the charging unit 103. The charged photoconductor surface is irradiated with laser light from the writing device 100, whereby an electrostatic latent image is formed on the photoconductor drum 102 surface. In the case of a color image, the image information exposed to each photosensitive drum 102 is single-color image information obtained by separating a desired full-color image into yellow, magenta, cyan, and black color information. Each color toner is applied from the developing device 104 to the electrostatic latent image formed in this way, and visualized as a toner image.

  Further, the intermediate transfer belt 107 is driven to run counterclockwise in the figure, and in each image forming unit 101, the toner images of each color are sequentially transferred from the photosensitive drum 102 to the intermediate transfer belt 107 by the action of the primary transfer roller 106. The In this way, the intermediate transfer belt 107 carries a full-color toner image on its surface.

  Note that any one of the image forming units 101 can be used to form a single-color image or a two-color or three-color image. In the case of monochrome printing, image formation is performed using the rightmost Bk unit (101d) of the four process cartridges.

  The residual toner adhering to the surface of the photosensitive drum after the toner image is transferred is removed from the surface of the photosensitive drum by the cleaning unit 105, and then the surface is subjected to the action of the static eliminator to initialize the surface potential. Prepare for the next image formation.

  On the other hand, paper is fed from the paper feed tray 121 and is sent toward the secondary transfer position by the registration roller pair 124 in timing with the toner image carried on the intermediate transfer belt 107. The toner image on the surface of the intermediate transfer belt is collectively transferred onto the sheet by the action of the secondary transfer roller 111. When the sheet on which the toner image has been transferred passes through the fixing device 112, the toner image is fused and fixed to the sheet by heat and pressure. The fixed sheet is discharged to the discharge tray 115 by the discharge roller 114.

Note that the image formation is not limited to the image formation based on the image information of the document read by the reading unit 130, and the image formation can be performed based on the image information from an external device such as a personal computer.
As mentioned above, although this invention was demonstrated by the example of illustration, this invention is not limited to this. For example, a sensor having an appropriate configuration and system can be used as a sensor that detects the open / closed state of the cover. The automatic document feeder can also adopt an appropriate configuration within the scope of the present invention. The configuration of the image reading apparatus is arbitrary.

  The configuration of the image forming apparatus is also arbitrary, and the arrangement order of the color image forming units in the tandem system is arbitrary. Further, not only the intermediate transfer method but also a direct transfer method may be used. Furthermore, it is not limited to the tandem type. Further, a full color machine using three color toners, a multicolor machine using two color toners, or a monochrome apparatus may be used. Of course, the image forming apparatus is not limited to a copying apparatus, but may be a printer, a facsimile machine, or a multifunction machine having a plurality of functions.

1,140 Automatic document feeder 2,130 Image reading device 5 Document stacking table 6 Document 8 Document set detection filler 29 Upper cover 30 Upper cover open / close detection sensor (open / close detection means)
30a Detected part (filler)
31a, 31b Lock portion 32a, 32b Locked portion 38 Document set detection sensor (document set detection means)
38a Detected part (filler)
50 Control unit 51 Operation panel 110 Image forming unit 120 Paper feed unit 150 In-body paper discharge unit

JP 2009-198708 A

Claims (8)

In an automatic document feeder that feeds documents one by one from a bundle of documents set in a document setting section and conveys them to a predetermined reading position,
An open / close cover provided in the apparatus main body, an open / close detecting means for detecting an open / closed state of the open / close cover, and an original set detecting means for detecting an original set on the original setting unit,
The opening / closing detection means and the document set detection means are arranged on each side of the opening / closing cover in the rotational axis direction,
An automatic document feeder having control means for determining an open / close state of the opening / closing cover based on a detection output of the opening / closing detection means and a detection output of the document set detection means.   2. The automatic document feeder according to claim 1, wherein the opening / closing detection unit and the document set detection unit are respectively disposed in an area where displacement is greatest when the opening / closing cover is twisted. 3. The open / close detection means and the document set detection means each include a detection sensor and a detected member, and at least the detected member is provided on the open / close cover,
3. The detection member according to claim 1, wherein the detection member having a higher strength among the detection member of the opening / closing detection unit and the detection member of the document set detection unit is arranged on the front side of the apparatus. Automatic document feeder.   The automatic document feeder according to any one of claims 1 to 3, wherein the open / close detection means is arranged on the back side of the apparatus.   2. The automatic document feeder according to claim 1, wherein the control unit detects the open / close detection unit after the output of the document set detection unit is turned on.   Informing means for informing the user of information and warning, the control means is based on the detection output of the opening / closing detection means and the detection output of the document set detection means, the opening / closing state of the opening / closing cover and the presence or absence of jammed documents The automatic document feeder according to claim 1, wherein the automatic document feeder is notified.   An image reading apparatus comprising the automatic document feeder according to claim 1. An image forming apparatus comprising an image reading device, wherein the image reading device includes the automatic document feeder according to claim 1.

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