JPH0688717B2 - Sheet transfer device - Google Patents

Description

The present invention relates to a sheet conveying device in an image forming apparatus such as a copying machine and a printing machine, and more specifically, to separating sheets on a drum or a sheet conveying direction. The present invention relates to a sheet conveying device having a guide member that is displaced when switching between the sheet and the sheet.

(B) Conventional Technology Conventionally, in a sheet conveying apparatus having a guide member, for example, in a color copying machine, in a sheet conveying apparatus having a separation claw (guide member) for separating a sheet held on a drum, a sheet feeding apparatus is used. The sheet conveyed from the unit is brought into close contact with the surface of the transfer drum and integrally rotated a number of times, and the images of the respective colors developed on the photosensitive drum are transferred to the sheet on the transfer drum in multiple transfer. Then, the separation claw normally arranged at the standby position that does not contact the transfer drum moves to a guide position for separating the sheet on the transfer drum, separates the sheet from the transfer drum, and separates the sheet. Transport along.
At that time, the sheet may be jammed (jam) in the conveyance. However, if the conveyance device of the copying machine is continuously operated in the state where the conveyance jam occurs, not only the sheet is not conveyed accurately, It also induces breakdown. Therefore, a sheet detecting means including a light source (light emitting diode) and a light receiving element (phototransistor) is arranged across the sheet conveying path passing through the separation claw, and when the sheet passes through the position, the sheet detecting means is provided. When the passage of the sheet on the separation claw is detected by the light being blocked, and when the passage of the sheet is not detected at a predetermined time, the copying operation is stopped because the conveyance jam occurs, and the sheet conveyance and conveyance device is inaccurate. Prevent the failure of.

(C) Problems to be solved by the invention By the way, the separation claw is switched from the standby position to the guide position to separate and convey the sheet on the transfer drum. When developing an image, toner is scattered near the transfer device of a copying machine, especially an electrophotographic copying machine, and the toner is sufficiently deposited on the solenoid and the drive transmission unit that are the drive source that moves the separation claw from the standby position to the guide position. If a sufficient driving force is not obtained and the separation claw is not moved to the guide position, the sheet on the transfer drum reaches the separation position, deviates from the predetermined sequence, and the sheet detection is not performed by the sheet detection unit, and the copying operation is performed. It may stop. Further, the malfunction of the separation claw may cause the conveyed sheet to collide with the separation claw, and a load may be applied to the separation claw to impair the separation / conveyance function. But,
The above-mentioned sheet detecting means cannot detect the malfunction of the separating claw, and cannot detect the trouble due to the malfunction of the separating claw.

(D) Means for Solving the Problem The present invention is intended to solve the above problems, and is configured such that a guide member such as a separating claw can be switched between a standby position and a guide position. At the guide position of the guide member, the sheet is conveyed along the guide member, and the passage of the sheet on the guide member due to the conveyance is detected by a detecting unit including a wave transmitting element such as a light source element and a wave receiving element. In the sheet conveying device, a vertical hole is formed on a surface of the guide member that conveys and guides the sheet, and the detection unit prevents the wave from the wave transmitting element from being blocked by the vertical hole at the standby position of the guide member. Is not received by the wave receiving element, and is arranged so that the wave from the wave transmitting element is received by the wave receiving element through the vertical hole at the guide position, In the sheet conveying apparatus, the passage of the sheet can be detected and the switching position of the guide member can also be detected.

(E) Action Based on the above-mentioned means, when the guide member is switched to a position other than the guide position, the wave receiving element does not receive the wave from the wave transmitting element because the wave receiving element is blocked by the vertical hole and the guide member moves to the guide position. It detects that it has not been switched to. When the guide member is switched to the guide position, the wave receiving element receives the wave from the wave transmitting element guided through the vertical hole and detects that the wave is switched to the guide position. Then, the sheet is conveyed along the guide member switched to the guide position, and the passage of the sheet by the conveyance on the guide member is detected by the detecting means.

(F) Embodiments Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 and 2, a transfer drum 1 is rotatably arranged in the main body of the color copying machine, and a plurality of grippers 2 are swingably arranged on the transfer drum 1. Then, the edge of the sheet S that is in close contact with the surface of the transfer drum 1 is held. A separation claw 3 is swingably arranged on a shaft 5 in the main body of the apparatus so as to face the transfer drum 1. The separation claw 3 is connected via a swing arm 6 connected to the end side surface of the separation claw 3. It is interlocked with the solenoid 7 and is urged upward by a spring 9. Further, a pin 10 is arranged on the main body of the device below the separating claw 3, and
The downward swinging position of the separation claw 3 is regulated by 10.
Normally, the separation claw 3 is rotated to the standby position A in the upward direction by the urging force of the spring 9, and when the transfer drum 1 rotates a predetermined amount and receives the separation signal, the transfer drum 1
The solenoid 7 is excited in synchronism with the predetermined rotation position of the
The sheet S is brought into contact with the sheet 10, and the sheet S on the transfer drum 1 is switched and held at a guide position B where the sheet S is separated and conveyed.

A cylindrical vertical hole 11 having a predetermined depth is provided at the center of the upper surface of the separation claw 3, and a light receiving element 12 such as a phototransistor is provided at the bottom of the vertical hole 11. Further, when the separation claw 3 is stopped and held at the guide position B, a light source 13 such as a light emitting diode is arranged in the device main body facing the light receiving element 12, and the separation claw 3 is guided to the guide position B. Light from the light source 13 only when the
Is received by. Then, as shown in FIG. 3, when the light from the light source 13 is received by the light receiving element 12, the light receiving signal H is output from the light receiving element 12 to a control unit (not shown), and the light source 13
The cutoff signal L is output in the state where the light from is not received by the light receiving element 12.

Since the present embodiment is configured as described above, the sheet S conveyed from the sheet feeding section (not shown) is held by the gripper 2 at its end, and is brought into close contact with the surface of the transfer drum 1 to be integrated. The sheet S is rotated several times, and the sheet S on the transfer drum 1 is rotated.
Then, the images separated into respective colors (not shown) and developed on the photoconductor drum are transferred in multiple. At that time, the separation claw 3 is rotated to the standby position A by the urging force of the spring 9,
The light from the light source 13 is not guided to the vertical hole 11 of the separation claw 3, the light receiving element 12 does not receive the light, and the light receiving element 12 outputs the cutoff signal L to the control unit (not shown) ( Third
Figure (b) b). Further, when the transfer drum 1 is rotated a predetermined number of times and the gripper 2 holding the sheet S comes to the front of the separation position where the sheet S is separated / conveyed on the transfer drum 1, the solenoid 7 is excited synchronously. , Rotate the separation claw 3 downward and switch to the guide position B where it abuts the pin 10.
Hold. Then, at the guide position B, the light from the light source 13 is guided to the vertical hole 11 of the separation claw 3, the light is received by the light receiving element 12, and the light receiving signal H is output from the light receiving element 12 to the control unit ( (B) of FIG. 3 (b). Then, the gripper 2 is opened along with the rotation of the separation claw 3 to the guide position B, and the sheet S on the transfer drum 1 is separated from the transfer drum 1 by the separation claw 3 and along the separation claw 3. When the leading edge of the sheet S passes over the vertical hole 11 and the light from the light source 13 is cut off, the light receiving element 12 outputs a cutoff signal L to the control section (see FIG. 3B). ). Further, when the sheet S is conveyed and passes over the vertical hole 11, the light from the light source 13 is again received by the light receiving element 12, and the light receiving signal H is output to the control section (see FIG. 3 (b)). ). Then, when the control section receives the predetermined sequence signal consisting of a, b, and c, the excitation of the solenoid 7 is released, and the separation claw 3 is returned to the standby position A by the biasing force of the spring 9. Thereby, the light of the light source 13 is
Similarly to the above, the light-receiving element 12 does not receive light, and the light-receiving element 12 outputs the interruption signal L to the control section again (e in FIG. 3 (b)), and the sheet conveying apparatus is operating normally. Is detected and the next sequence of copiers is continued. In addition, when the movement of the separation claw 3 to the guide position B is detected from the detection means including the light receiving element 12 and the light source 13 (b), but the passage signal (c) of the sheet S is not detected at a predetermined time,
The copying operation is stopped because the conveyance jam occurs.

In addition, the transfer drum 1 to which the sheet S is closely attached is
When the separation claw 3 is not rotated to the guide position B due to some trouble, even if the separation claw is rotated to the separation position and the separation claw start signal is transmitted, the light of the light source 13 is received by the light receiving element 12.
The light-receiving element 12 continues to output the cutoff signal L without receiving light. In this case, according to a command from the control unit, the gripper 2 holding the sheet S is not opened, the transfer drum 1 is rotated once again, and the activation signal of the separation claw 3 is transmitted again during the rotation. As a result, when the separation claw 3 is rotated and switched to and held at the guide position B, the light of the light source 13 is received by the light receiving element 12 and the light reception signal H is output to the control unit, and the transfer is performed as described above. The sheet S on the drum 1 is separated and conveyed. Even if the restart is repeated a predetermined number of times, if the separation claw 3 is not rotated to the guide position B, the light-receiving element 12 still outputs the interruption signal L to the control unit.
The copying operation of the copying machine is stopped.

In the above-described embodiment, the light receiving element 12 is arranged at the bottom of the vertical hole 11 provided in the separation claw 3, but as shown in FIG. When the light receiving element 12 is arranged in the main body of the apparatus facing the light source 13 through the vertical hole 11 'with the claw 3 stopped at the guide position B, the vertical width of the separation claw 3 serves as an optical path for the light from the light source 13. It is possible to detect the switching position of the separation claw 3 with higher accuracy.

Next, an embodiment in which the detecting means according to the present invention is applied to a branch piece for sorting the sheet S conveyed in the copying machine in each conveying direction will be described with reference to FIGS. 5 and 6.

A branch piece 3'is swingably arranged by a shaft 5 at a branch portion of the transfer device of the copying machine, and the branch piece 3'is provided with a pin 18 on the main body via a pin 14 arranged on the end side surface thereof. It abuts on the swing arm 6 which is pivotally supported by. Further, the other end of the swing arm 6 is interlocked with a solenoid 7, and a spring 9 is stretched over the pin 14 to urge the branch piece 3'upward. Further, an inversion path 15 is formed in front of the branch piece 3 ', and further in the rear thereof, an introduction path 16 and a branch piece 16 which are communicated with the inversion path 15 by switching the branch piece 3'to the standby position A. A discharge path 17 communicating with the path 15 is formed by switching 3'to the guide position B. Then, normally, the branch piece 3'is rotated upward by the biasing force of the spring 9 and comes into contact with the end of the path 17 to wait position A.
When the solenoid 7 is excited, the branch piece 3 ′ is rotated downward and comes into contact with the end of the path 16 to be switched to and held at the guide position B.

In addition, a vertical hole 11 on the cylinder with a predetermined depth is formed on the upper surface of the branch piece 3 '.
a is provided, and the upper surface light receiving element is provided at the bottom of the vertical hole 11a.
12a is provided, and a cylindrical vertical hole 11b having a predetermined depth is provided on the lower surface of the branch piece 3 ', and a lower surface light receiving element 12b is provided at the bottom of the vertical hole 11b. When the branch piece 3'is switched to the standby position A, the lower surface light source 13b is arranged in the main body of the apparatus facing the lower surface light receiving element 12b on the lower surface of the branch piece 3 ', and the branch piece 3'is guided. When switched to the position B, the upper light source 13a is arranged in the apparatus main body facing the upper light receiving element 12a on the upper surface of the branch piece 3 '.

Since this embodiment has the above-described structure, the branch piece 3 '
Is switched to the standby position A by the urging force of the spring 9, the light of the upper surface light source 13a is blocked by the vertical hole 11a and does not reach the light receiving element 12a, and the light receiving element 12a outputs the cutoff signal L. At the same time, the light from the lower surface light source 13b is received by the lower surface light receiving element 12b, and the light receiving signal H is output from the light receiving element 11b. Then, the sheet S is conveyed from the direction of the path 16 and the leading edge of the sheet S faces the lower surface light receiving element 12b.
When the light of the lower surface light source 13b is cut off after passing over 6, the cutoff signal L is output from the light receiving element 12b. Further, the sheet S
When the light has been conveyed and has finished passing over the lower surface light receiving element 12b, the light from the lower surface light source 13b is again received by the light receiving element 12b, and the light receiving signal H
Is output. As a result, the passage of the sheet S is detected, and it is determined that the sheet S is guided to the branch piece 3 ′ and conveyed to the reversing path 15. Then, the sheet S is the reversing path.
When it is reversed at 15, the solenoid 7 is excited in synchronization with this, and the branch piece 3 ′ is rotated to the guide position B against the biasing force of the spring 9. Then, the light of the upper surface light source 13a, which has not reached the vertical hole 11a until now, is received by the upper surface light receiving element 12a, the light receiving signal H is output from the light receiving element 11a, and the branch piece 3'is switched to the guide position B. Is detected. Then, the sheet S conveyed from the reverse path 15 direction
Is guided by the branch piece 3'at the guide position B, and the discharge path
The sheet S is conveyed to 17, and similarly to the above, the sheet S passes through the upper surface light receiving element 11a, the light from the upper surface light source 13a is blocked, the light blocking element L is output from the light receiving element 11a, and the sheet S finishes passing. Accordingly, the light receiving signal H is output again from the light receiving element 11a. As a result, the switching position of the branch piece 3'and the passage of the sheet S are detected, and when an abnormality occurs, the copying operation of the copying machine is stopped by a command from the control unit.

In the above description, the upper light source 13a and the light receiving element 12a detect the switching positions A and B of the branch piece 3 ', but at the same time, the lower light source 13b and the light receiving element 12b detect the switching position of the branch piece 3'. Further accuracy may be ensured. That is,
When the branch piece 3'is in the standby position A, the upper surface light receiving element 12a
Emits a cutoff signal L and the lower surface light receiving element 12b receives the light receiving signal H.
When the branch piece 3'is in the guide position B, the upper surface light receiving element 12a emits the light receiving signal H and the lower surface light receiving element 12b emits the cutoff signal L.

Further, in the above two embodiments, the separation claw 3 and the branch piece 3 '.
Although the guide member that operates by the swinging motion is used, it goes without saying that a guide member that operates by parallel movement or the like may be used.

Further, although the detecting means utilizing light such as the light source 13 and the light receiving element 12 is used, it goes without saying that the detecting means utilizing ultrasonic waves or the like may be used.

(G) Effect of the Invention As described above, according to the present invention, the wave transmission element 13
And the wave receiving element 12, the detection means, the guide member 3,
At the waiting position A of 3 ', the wave receiving element 12 does not receive the wave from the wave transmitting element 13 because it is obstructed by the vertical holes 11, 11', 11a, 11b, and at the guide position B, the wave receiving element passes through the vertical hole. The element 12 is arranged so as to receive the wave from the wave transmitting element 13, detects the passage of the sheet S, and guides the guide member 3,
Since it is configured to detect the switching position of 3 ',
Conventionally, the switching position of the guide members 3, 3'is also detected by the detecting means which is used only for detecting the passage of the sheet S,
It is possible to detect malfunctions of the guide members 3 and 3 ', and use the middle stage of unnecessary copying operation to provide delayed motion of the guide members 3 and 3'.
In addition, it is possible to prevent the sheet S from colliding with the guide members 3 and 3 ', and to smoothly convey the sheet S.

[Brief description of drawings]

FIG. 1 is a side view showing an embodiment in which the present invention is applied to a separating claw of a transfer drum, FIG. 2 is a perspective view thereof, and FIG. 3 shows a relationship between a wave transmitting element and a wave receiving element applicable to the present invention. In the figure, (a) is a rotation diagram thereof, (b) is a diagram showing an output signal transmitted from the wave receiving element, and FIG. 4 is a side view showing an embodiment obtained by partially modifying the embodiment of FIG. FIG. 5 is a perspective view showing an embodiment in which the present invention is applied to a branch piece of a conveying device, and FIG. 6 is a side view thereof. 1 ... Transfer drum, 3, 3 '... Guide member, (3 ... Separation claw,
3 '... branch piece), 11, 11', 11a, 11b ... vertical holes, 12, 12a, 12b
... Wave receiving element (light receiving element, phototransistor), 1
3,13a, 13b ... Wave transmission element (light source, light emitting diode)

Claims (1)

[Claims] 1. A guide member configured to switch between a standby position and a guide position, conveys a sheet along the guide member at the guide position of the guide member, and guides the sheet by the conveyance. In a sheet conveying device for detecting an upper passage by a detecting means composed of a wave transmitting element and a wave receiving element, a vertical hole is formed on a surface of the guide member for conveying and guiding the sheet, and the detecting means is used for the guide member. In the standby position, the wave from the wave transmitting element is blocked by the vertical hole and is not received by the wave receiving element, and in the guide position, the wave from the wave transmitting element passes through the vertical hole to receive the wave. It is arranged so as to be received by an element, and the detection means is configured to detect the passage of the sheet and also the switching position of the guide member. Sheet transport device.