JPH08113388A - Sheet jam detection device - Google Patents

Abstract

PURPOSE: To provide the jamming detection device for which the number of sensors can be reduced or simplifying the constitution inside a copying machine or the like, and in which the sensor installation freedom degree can be improved. CONSTITUTION: The jamming detection device for sheets detects sheets P at plural positions from an upstream part to a downstream part in a carrier passage L for the sheets P. Driving members 27a,... are disposed to cross the carrier passage at the plural positions of the carrier passage, so the driving members 27a,... are pushed by tip edges of the sheets P being carried to be moved. Otherwise, the drive members 27a,... are supported on a holder 21, so a position of the holder 21 is displaced by move of the drive members 27a,..., and the displacement of the position of the holder 21 is detected by a sensor 33.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jam detecting device for detecting stagnation of a sheet in an apparatus having a sheet conveying mechanism such as a printing machine such as a copying machine or a printer.

[0002]

2. Description of the Related Art An apparatus for forming an image on a sheet such as a printing machine or a copying machine is provided with a sheet feeding mechanism for conveying the sheet. For example, in a copier or the like, a paper feed cassette filled with paper is loaded into the copier, and the paper is taken out one by one from the paper feed cassette, passes through a transfer device and a fixing device, and reaches a paper ejection tray. Conventionally, in order to normally operate a copying machine or the like, when a paper jam occurs at any place in the paper conveyance path, this is detected. Then, the paper feeding mechanism such as rollers arranged on the conveying path is stopped to prevent secondary damage to the copying machine. In order to detect such a paper jam, conventionally, sensors that detect the paper are arranged at a plurality of positions in the paper conveyance path.

[0003]

However, in the above-described detecting device, the sensors must be arranged at a plurality of positions in the sheet conveying path, which complicates the internal structure of the copying machine and the like. There is a problem that the location of the sensor is also limited due to the space limitation.

The present invention has been made in order to solve the above-mentioned problems, and the number of sensors can be reduced. Therefore, the internal structure of a copying machine or the like can be simplified and the sensors can be installed. It is an object of the present invention to provide a jam detection device capable of increasing the degree of freedom of the above.

[0005]

In order to achieve the above object, the present invention is directed to detecting a jam of a sheet-like article by detecting the sheet-like article at a plurality of locations from an upstream portion to a downstream portion of a sheet-like article conveying path. An apparatus, which is arranged at a plurality of positions of the above-mentioned transfer path so as to intersect with the same transfer path, and is driven by the leading edge of the sheet-shaped article being transferred, and a drive member, and the movement of the drive member. It is characterized in that it is provided with a holder whose position can be displaced by a vertical movement and a sensor which detects the displacement of the position of the holder.

[0006]

In the jam detecting device for sheet-like articles having the above-mentioned structure, the sheet-like articles conveyed from the upstream portion to the downstream portion of the conveying path are brought into contact with the driving member one after another and moved, Displace the position of the holder. Since the displacement of the position of the holder is detected by the sensor, it is possible to know that a jam has occurred at a position before the drive member by detecting that the drive member does not move at the timing of displacement. .

[0007]

【Example】

A. First Embodiment (1) Configuration of First Embodiment A first embodiment of the present invention will be described below with reference to FIGS. 1 to 4. In FIG. 1, reference numeral 1 is a main body of an electrophotographic printer in which this embodiment is used. First,
Explaining the schematic configuration of the printer, the sheets (sheet-like articles) P filled in the sheet feeding cassette 2 are sent out one by one by a feed roller 3, and are supplied to an image forming unit 5 via a registration roller 4. The image forming unit 5 is composed of a photosensitive drum 6 and a developing device 7 which are integrally formed. The image forming unit 5 is detachably attached to the main body 1 and is new when the toner filled in the developing device 7 is consumed. It is supposed to be replaced.

A transfer charger 8 is disposed above the photoconductor drum 6 so that it can be brought into contact with and separated from the photoconductor drum 6. The transfer charger 8 is charged with a charge having a polarity opposite to that of the toner of the toner image formed on the surface of the photosensitive drum 6,
The toner image is transferred onto a sheet inserted between the transfer charger 8 and the photoconductor drum 6. Then, the paper P on which the toner image is transferred is supplied to the fixing device 9 and the toner image is fixed. Next, the sheet P exiting the fixing device 9 is turned upward by approximately 180 degrees by the guide 10 and then ejected to the sheet ejection tray 12 by the sheet ejection roller 11.

The above is the basic configuration of the printer of the embodiment, and this printer is provided with the jam detecting device A having the following configuration. Jam detection device A of the embodiment
As shown in FIG. 1, a position F in front of the fixing device 9 in the conveyance path L of the paper P (hereinafter, this position is referred to as “forward path position (outgoing path portion)”) and above the forward path position F. In addition, the rotary sensor 20 having an impeller shape is provided at an intermediate portion between a position before the paper discharge roller 11 (hereinafter, this position is referred to as a "return path position (return path portion)").

In FIG. 2, reference numeral 21 is a hub (holder) forming the base of the rotary sensor 20. Hub 2
Reference numeral 1 denotes a disc, and is rotatably supported by a shaft 22 (see FIG. 3). On the outer peripheral surface of the hub 21, three blades (driving members) 27a, 2 projecting outward in the radial direction thereof.
7b and 27c are formed at equal intervals in the circumferential direction. The blades 27a, ... Are made of thin plates, and the side portions thereof facing the direction opposite to the rotation direction extend substantially linearly along the radial direction.

Now, assuming that the blade 27a is arranged at the forward path position F, the blade 27a is rotated by 60 ° by the paper sheet P as the paper sheet P passes through the forward path position F.
As a result, the adjacent blade 27b is arranged so as to cross the return path position R. Then, when the paper P reaches the return path position R via the fixing device 9, the blade 27b is moved to 60 by the paper P this time.
The blade 27c is rotated by an angle of .degree. In this way, the rotary sensor 20
Is 6 every time the paper P passes through the forward path position F and the backward path position R.
The blades 27a, ... Are rotated by 0 ° so that any one of the blades 27a, ... Is alternately arranged at the forward path position F and the backward path position R. The rotary sensor 20 is arranged at a position outside the image area of the paper P so as not to disturb the toner image formed on the surface of the paper P.

The rotation of the rotary sensor 20 as described above is detected by the sensor unit 30 shown in FIGS. In the figure, reference numeral 31 is a casing.
The casing 31 is formed integrally with the hub 21 and has a cylindrical shape. On the outer circumference of the casing 31, twelve detectors 32, ... Which project outward in the radial direction are formed at equal intervals in the circumferential direction. Of the detectors 32, ..., The three are arranged at 120 ° around the center of the casing 31 and are arranged so that their centers coincide with the substantially linear side portions of the blades 27a ,. .

On the other hand, below the casing 31, a sensor 33 supported by a frame (not shown) is arranged. An optical sensor such as a photo interrupter is used as the sensor 33. The sensor 33 is provided with a light emitting portion 33a and a light receiving portion 33b, which have a common optical axis, facing each other. The sensor 33 has a detector 32 passing between the light emitting portion 33a and the light receiving portion 33b. Light receiving section 33b
When is shielded from light, a detection signal is supplied to a controller (not shown). As the sensor 33, a magnetic sensor such as a proximity switch or a mechanical sensor such as a limit switch may be used. With this configuration, each time the rotary sensor 20 rotates by 30 °, the detector 32 shields the light receiving portion 33b of the sensor 33 from light, and the detection signal is supplied to the controller.

Next, as shown in FIG.
As shown in, a plurality of teeth 34 are formed. Tooth 34
One surface is formed along the radial direction of the casing 31, and the other surface is formed so as to form an acute angle with this surface. On the other hand, a spring pedestal 35 is attached to the shaft 22, and one end of a coil spring 36 is attached to the spring pedestal 35. At the other end of the coil spring 36, a stopper 37 is attached which is slidably supported in the radial direction by a guide (not shown). The tip portion of the stopper 37 is obliquely cut off and engages with the groove of the tooth 34 in a disengageable manner. Thus, when the casing 31 tries to rotate in the direction of the arrow in the figure, the stopper 37 is retracted to allow the rotation, and when trying to rotate in the opposite direction, the stopper 37 engages with the teeth 34 and It is designed to prevent rotation.

(2) Operation of the First Embodiment Next, the operation of the jam detecting device having the above construction will be described. When the signal for instructing the start of the printer operation is supplied, the paper P is sent out from the paper feed cassette 2 by the feed roller 3, and is supplied to the image forming unit 5 via the registration roller 4. The paper P on the surface of which the toner image is formed in the image forming unit 5 is conveyed toward the fixing device 9. At that time, the paper P reaches the outward position F and the blade 27
When it comes into contact with a, the blade 27a rotates as the paper P advances. Then, when the blade 27a rotates by 60 °, the blade 27a separates from the sheet P and does not rotate any more.

When the sheet P passes the forward path position F, the adjacent blade 27b is rotated to the backward path position R as shown by the broken line in FIG. Here, in FIG. 2 and FIG.
The portion of the blade 27a indicated by the solid line that is substantially linear is orthogonal to the sheet P, but this is a state in the middle of rotation, and in the actual stationary state, the blade 27a is shown in FIG. It is located backward from the position by the angle θ in rotation direction,
Detecting element 32 located on the linear side of the blade 27a
Is at a position displaced from the sensor 33. Therefore, while the rotary sensor 20 rotates and the blade 27a rotates by 60 °, the light receiving portion 33b of the sensor 33 keeps the blade 2a.
The detector 32 aligned with the linear portion of 7a, and the detector 3
The light is shielded from light twice by one detector 32 following 2 in total.

The sheet P that has passed the forward path position F is subjected to the fixing action of the toner image by the fixing device 9 and is guided by the guide 10.
After that, the sheet is conveyed toward the discharge roller 11. At that time, when the sheet P reaches the return path position R and comes into contact with the blade 27b, the blade 27b rotates as the sheet P advances. Then, when the blade 27b rotates by 60 °, the blade 27b separates from the sheet P and does not rotate any more. Further, while the rotary sensor 20 rotates by 60 °, the light receiving portion 33b of the sensor 33 is shielded from light by the detectors 32, 32 twice.

When a paper jam occurs on the upstream side of the forward path F in the transport path L for the paper P, the sensor 33 supplies a detection signal to the controller at the timing when the paper P passes the forward path F. do not do. In this case, the controller stops the operation of the printer, displays a notification on the switch panel (not shown) arranged on the main body 1 that there is a paper jam, and indicates the approximate location of the paper jam (for example, the registration roller 4). (Near) is displayed.

When the leading edge of the paper P slightly rotates the blades 27a, ... Of the rotary sensor 20, the paper P
However, the image forming unit 5 may be clogged and stopped. In this case, since the light receiving portion 33b of the sensor 33 is shielded only once at the timing when the paper P passes the forward path position F, the operation of the printer is stopped based on one detection signal supplied from the sensor 33. Along with
It is possible to perform control so as to perform a display notifying that effect on the switch panel and a display indicating an approximate location where the paper jam has occurred (for example, near the image forming unit 5).

Similarly, when the fixing device 9 causes a paper jam after the sheet P passes the forward path position F, the sensor 33 does not supply a detection signal to the controller at the timing when the sheet P passes the backward path position F. In this case, the controller stops the operation of the printer, and displays a message indicating that a paper jam has occurred on the switch panel and a display indicating an approximate location where the paper jam has occurred (for example, near the fixing device 9). .

In the same manner as described above, it is conceivable that the paper P may be jammed and stopped by, for example, the fixing device 9 when the leading end of the paper P slightly rotates the blades 27b, .... In this case, since the light receiving portion 33b of the sensor 33 is shielded only once at the timing when the paper P passes the forward path position F, the operation of the printer is stopped based on one detection signal supplied from the sensor 33. At the same time, it is possible to perform control so as to display a notification to that effect on the switch panel and a display indicating a rough place where the paper jam has occurred (for example, near the guide 10).

In the jam detecting device A having the above structure,
The sheets P transported from the upstream side to the downstream side of the transport path L successively come into contact with the blades 27a, ...
The rotation of the rotary sensor 20 causes the rotation of the sensor 3
3 detected. In this way, the single rotary sensor 20 and the sensor 33 have a simple configuration in which the blades 27a, ...
It is possible to detect the paper P at a plurality of points on the transport path L. Therefore, as described above, the jam detecting device A
The configuration is simplified, and more space is saved as compared with the conventional configuration in which, for example, optical sensors are arranged at a plurality of positions on the transport path L. Particularly, in the above-described embodiment, since the rotary sensor 20 is arranged in the middle of the forward path position F and the backward path position R, the rotary sensor 2 is used.
0 functions extremely efficiently, and the configuration can be further simplified.

B. Second Embodiment Next, a second embodiment of the present invention will be described with reference to FIGS. In the second embodiment, the same constituent elements as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. In the jam detecting device B of the second embodiment, in the conveyance path L of the paper P, the first forward path position F1 intermediate between the registration roller 4 and the image forming unit 5 and the intermediate forward position F1 between the image forming unit 5 and the fixing device 9. The sheet P is configured to be detected at the second forward position F2 (the same as the forward position F in the first embodiment) and the backward position R.

As shown in the figure, the first and second outward position F
1, F2 and the return path position R, a slider (holder) 40 whose longitudinal direction is substantially parallel to the horizontal conveyance direction of the paper P.
Is arranged. The slider 40 is slidably supported in its longitudinal direction by a guide (not shown). Further, the slider 40 is pulled to the left side in the figure by a coil spring 41 attached to the frame 1a of the main body 1, and its left end portion is brought into contact with the stopper 42 to be positioned at the initial position. In addition, the slider 40
A claw 43 protruding laterally is fixed to the. Nail 43
Has a right-angled triangular shape in plan view.

On the other hand, in the main body 1, a pair of levers (driving members) 45, 45 are arranged apart from each other in the longitudinal direction of the slider 40. Each lever 45 is rotatably supported by a shaft 46 in the direction along the paper surface of FIG. The lower end portions of the levers 45, 45 have first and second outward path positions F.
It is arranged so as to traverse 1, F2. Further, the upper end portion of the lever 45 is cut at one of its corners to form a circular arc portion 45a, and a flat side portion opposite to the circular arc portion 45a is engaged with the claw 43. Further, the lever 45 has a shaft 46.
It is possible to swing about a predetermined angle in a direction orthogonal to the paper surface in FIG. Such a lever 45 is held in an upright posture by the weight of its lower end.

A lever 47 is arranged on the main body 1 so as to be located at the left end of the slider 40. The upper end of the lever 47 is arranged so as to cross the return path position R,
Further, the lower end portion is supported by the shaft 48 so as to be rotatable in the direction along the paper surface of FIG. Further, the lever 47 is provided on the shaft 4
It is possible to swing about 8 at a predetermined angle in a direction orthogonal to the paper surface of FIG. The lever 47 is in contact with a guide 50, which will be described later, by its upper end being biased toward the slider 40 by a spring (not shown). Further, the lever 47 is biased in a counterclockwise direction in the figure by a spring or the like (not shown), and is held in an upright state by abutting against the stopper 49. On the other hand, on the side of the upper end of the lever 47, the guide 50
Is arranged. The guide 50, as shown in FIG.
It has an arcuate shape in a plan view and is arranged so as to be separated from the slider 40 toward the right side in the drawing.

Further, in the main body 1, a sensor 60 such as a photo interrupter is arranged with the light emitting portion 60a and the light receiving portion 60b thereof being vertically separated from each other. On the other hand, a detector 61 protruding laterally is fixed to the slider 40. The detector 61 shields the light receiving portion 60b from the light when the slider 40 is at the initial position, and slides the slider 40 to the right side in the figure to bring the light receiving portion 60b into the light receiving state.

(2) Operation of Second Embodiment Next, the operation of the jam detecting device B having the above configuration will be described. When a signal instructing to start the operation of the printer is supplied, the paper P is sent out from the paper feed cassette 2 by the feed roller 3, and is conveyed toward the image forming unit 5 via the registration roller 4. At this time, when the sheet P reaches the first forward path position F1 and contacts the lever 45, the lever 4
The sheet 5 is rotated according to the progress of the sheet P. Lever 45
When is rotated, the upper end of the lever 45 slides the slider 40 to the right in the figure via the claw 43. As a result, the light receiving portion 60b of the sensor 60 changes from the light blocking state to the light receiving state, and the detection signal is supplied from the sensor 60 to the controller.

Then, when the lever 45 reaches its pivoting end, the engagement with the claw 43 is released, and the slider 40 returns to the initial position by the elastic force of the coil spring 41. As a result, the light receiving portion 60b of the sensor 60 changes from the light receiving state to the light blocking state. Then, when the sheet P passes through the first outward path position F1 or the second outward path position F2 and the lower end portion of the lever 45 becomes free, the lever 45 tries to return to the original vertical position by its own weight. . At that time, the arc portion 45a of the lever 45 slides on the inclined surface 43a of the claw 43, whereby the upper end portion of the lever 45 slightly swings in the direction orthogonal to the paper surface of FIG. As a result, the upper end of the lever 45 rides over the top of the claw 43 and returns to the original state in which the lever 45 and the claw 43 are engaged.

The sheet P that has passed the first forward path position F1 is
The toner image is conveyed to the image forming unit 5, where a toner image is formed on the surface. Next, the sheet P is conveyed toward the fixing device 9, and at that time, the sheet P passes through the second forward path position F2, and the sheet P is detected in the same manner as above. Second outbound position F
The sheet P having passed through 2 is subjected to the fixing action of the toner image by the fixing device 9, and is conveyed toward the sheet discharge roller 11 via the guide 10. At that time, when the paper P reaches the return path position R and contacts the lever 47, the lever 47 rotates as the paper P advances. When the lever 47 rotates, the intermediate portion of the lever 47 slides the slider 40 to the right in the figure via the claw 43. As a result, the light receiving section 60b of the sensor 60 changes from the light blocking state to the light receiving state, and the sensor 60 supplies a detection signal to the controller.

Here, since the lever 47 rotates along the guide 50, the lever 47 is swung so as to be separated from the claw 43 as the lever 47 rotates. Then, when the lever 47 reaches the turning end, the engagement state with the claw 43 is released. As a result, the slider 40 returns to the initial position by the elastic force of the coil spring 41. Next, when the sheet P passes through the backward path position R and the upper end portion of the lever 47 becomes free, the lever 47 tries to return to the upright position by the elastic force of the spring or the like. At that time, the side portion of the lever 45 slides on the inclined surface 43a of the claw 43, whereby the lever 45 slightly swings in the direction orthogonal to the paper surface of FIG. As a result, the lever 47 moves the claw 4
The top of No. 3 is overcome and the original state where the lever 47 and the claw 43 are engaged is restored.

In this embodiment, when a paper jam occurs on the upstream side of the first forward path position F1 in the conveyance path L of the paper P, the timing at which the paper P passes the first forward path position F1. Moreover, the sensor 60 does not supply a detection signal to the controller. In this case, the controller stops the operation of the printer, displays an indication on the switch panel (not shown) arranged on the main body 1 that there is a paper jam, and displays the approximate location of the paper jam (for example, a paper feed cassette). (Near Exit 2)
Is displayed.

Further, when a paper jam occurs in the image forming unit 5 after the paper P has passed the first forward path position F1, the sensor 60 detects to the controller at the timing when the paper P passes the second forward path position F2. No signal is supplied. In this case, the controller stops the operation of the printer, and displays on the switch panel a message indicating that a paper jam has occurred and a display indicating a rough place where the paper jam has occurred (for example, the image forming unit 5).

Further, if the transfer device 9 causes a paper jam after the paper P passes the second forward position F2, the sensor 60 does not supply a detection signal to the controller at the timing when the paper P passes the backward position R2. . In this case, the controller stops the operation of the printer, and displays on the switch panel a message indicating that a paper jam has occurred and a display indicating an approximate location where the paper jam has occurred (for example, the transfer device 9).

When the front end of the paper P rotates the lever 45 slightly, the paper P may be jammed and stopped by the registration roller 4, for example, and the light receiving portion 60b of the sensor 60 may remain in the light receiving state. Conceivable. In this case, since the detection signal output from the sensor 60 remains on, it is possible to perform control so as to display, for example, the vicinity of the registration roller 4. Also, the second outward position F2
Also, when the paper P is stagnated at the return path position R and a similar phenomenon occurs, the second forward path position F2 and the return path position R can be controlled to be displayed as the location where the paper jam occurs.

In the jam detecting device B having the above structure,
With a very simple configuration in which the levers 45 and 47 are arranged on the conveyance path L of the paper P, the single sensor 60 can detect the paper P at a plurality of points on the conveyance path L. Therefore, the configuration of the jam detection device is simplified and space is saved. In particular, in the above-described embodiment, since the slider 40 is slid by the levers 45 and 47, the lever 45 can be arranged at an arbitrary position along the slider 40 to detect the paper P, and the design is free. The degree is increased.

C. Modification Example In the first embodiment, the rotary sensor 20 is provided with the three blades 27a, ..., But the number is arbitrary. For example, the number of blades may be two, and a weight may be attached to the lower blade so that the two blades are arranged at the forward path position F and the backward path position R by the gravity. In the first embodiment, the sensor 32 provided on the outer circumference of the casing 31 is configured to be detected by the sensor 33.
The blades 27a, ... May be detected by a sensor. In the second embodiment, the lever 45 is configured to return to its original position by its own weight, but it may be configured to be returned by an elastic member such as a spring.

[0038]

As described above, according to the jam detecting device of the present invention, the driving member is arranged at a plurality of locations on the conveyance path L so as to intersect with each other. It is possible to detect a sheet-like article, and therefore the configuration is simplified and space is saved (Claim 1). By arranging the holder in the middle of the forward path portion and the backward path portion, the jam detecting device functions efficiently (Claim 2), and further, the holder is rotatable and the driving member is alternately arranged in the forward path portion and the backward path portion. The configuration can be further simplified by adopting the configuration of arranging in (4). By supporting the holder slidably in the carrying direction and moving it by the lever that intersects the carrying path, it is possible to detect the sheet-like article at more places of the carrying path, and moreover, The detection position can also be arbitrarily selected (claim 3).

[Brief description of drawings]

FIG. 1 is a side sectional view showing an outline of a printer in which a jam detecting device according to a first embodiment of the present invention is used.

FIG. 2 is a plan view showing a rotary sensor.

FIG. 3 is a view of the rotary sensor shown in FIG. 2 viewed from the back side.

FIG. 4 is a view on arrow IV in FIG.

FIG. 5 is a side sectional view showing the outline of a printer in which the jam detecting device according to the second embodiment of the present invention is used.

FIG. 6 is a side view showing details of the jam detection device according to the second embodiment.

FIG. 7 is a view on arrow VII of FIG.

[Explanation of symbols]

20 ... Rotary sensor, 21 ... Hub (holder), 2
7 ... Blade (driving member), 33 ... Sensor, 40 ... Slider (holder), 45, 47 ... Lever (driving member), F ...
Forward path position (forward path portion), L ... Transport path, R ... Return path position (return path portion).

Claims (4)

[Claims] 1. A jam detecting device for a sheet-shaped article, which detects the sheet-shaped article at a plurality of locations from an upstream portion to a downstream portion of the sheet-shaped article transportation path, wherein the transportation path is provided at a plurality of locations of the transportation path. A drive member that is arranged so as to intersect with the sheet-like article that is conveyed and is moved by being pushed by the leading edge of the sheet-like article, a holder that can be displaced in position as the drive member moves, and displacement of the position of this holder. A jam detecting device for a sheet-shaped article, comprising: 2. The transport path has a forward path portion that advances in a predetermined direction and a return path portion that advances by passing through the forward path portion in a direction of about 180 ° and advances the holder to the forward path portion and the backward path portion. 2. The jam detecting device for the sheet-like article according to claim 1, wherein the driving member is provided in the middle of the sheet, and the driving member is arranged so as to intersect the forward path portion and the backward path portion. 3. The holder is slidably provided along the direction of the transport path, the drive member is rotatably supported at an intermediate portion thereof, and one end of the drive member intersects with the transport path. The jam detecting device for sheet-like articles according to claim 1, wherein the other end is configured by a lever engaged with the holder. 4. The holder is rotatably provided, and the drive member is arranged so as to project from the outer periphery of the holder to the outer peripheral side in the radial direction and to intersect the forward path portion or the return path portion. By moving the drive member arranged in one of the forward path portion and the return path portion by the sheet-like article, another drive member is arranged in the other of the forward path portion and the return path portion. The jam detection device for a sheet-shaped article according to claim 2, wherein the jam detection device is arranged in a line.