JPH11208924A - Sheet like member carrier device and image forming device having this carrier device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry a sheet like member in a stable state and eliminate generation of vibration and sudden sound, even when carrier speed or carrier load is changed, by providing a load means applying load to a rotation transmission means and changing this load by prescribed timing. SOLUTION: A load device is provided with an elastic member 38 on a supporting member 39, a friction member 37 which is pressed on a flat side surface 26d of a rotary disc body 26b by this elastic body 38 via a plane plate 40 and an actuator 35 operating a bar-shaped abutting member 35a which is abutted on the plane plate 40. When an instruction is given from a control part 36a to a driving part 36 by a detection signal, the actuator 35 projects the abutting member 35a in an (x) direction and abuts the abutting member 35a on the plane plate 40. By displacement of this plane plate 40, the friction member 37 and a plane part 38b of the elastic member 38 move in a direction that the member 37 and the part 38b separate from the flat side surface 26d. Thus, frictional force is reduced and load on a belt mechanism 26 can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like member conveying device for conveying a sheet-like member in an image forming apparatus such as a copier or a printer.

[0002]

2. Description of the Related Art A transport device for transporting recording paper from a paper feed tray section to a photosensitive drama in a conventional electrophotographic image forming apparatus will be described with reference to FIGS. The transfer device shown in FIG. 16 includes a recording sheet s from a lower feed tray (not shown) to an upper photosensitive drum (not shown).
Is transported through the transport guide unit 100. A first roller pair 131 including a first driving roller 101 and a first driven roller 102 is provided in the middle of the conveyance guide portion 100,
A second pair of rollers 132 including a second driving roller 111 and a second driven roller 112;
A third roller pair 133 including a first roller and a third driven roller 122 is provided, and conveys the recording paper s in the direction of arrow v in the figure. Each drive roller 101, 111, 121
Is driven to rotate by a drive mechanism (not shown) including a motor, a gear mechanism, a belt mechanism, and the like, and the rotation causes the driven rollers 102, 112, and 122 to be driven to rotate.

A problem in the transport operation of the conventional transport device as described above will be described with reference to FIG. FIG.
The change (a) of the load applied to the drive mechanism of the second drive roller 111 during the conveyance of the recording paper, the change (b) of the conveyance speed of the recording paper, and the change (c) of the sound pressure level by noise measurement are shown. . When the recording paper s conveyed from the first roller pair 131 enters the second roller pair 132 at time t1, the load applied to the drive mechanism increases as shown in FIG. At the same time, power transmission to the first drive roller 101 is interrupted, and the first roller pair 131 idles. Then, in order to increase the transport speed of the recording paper s at time t2, the second drive roller 111 is rotated at a higher speed, and the transport speed of the recording paper is increased as shown in FIG. At this time, the conveyance of the recording paper becomes unstable due to the speed fluctuation, so that the recording paper s collides with the conveyance guide unit 100 as shown in FIG. 16 and vibrations and sudden sounds are generated as shown in FIG. 17C. . When the recording paper s is further conveyed in the v direction and the leading end of the recording paper s enters the third roller pair 133 at time t3 and the rear end passes the first roller pair 131 at time t4, the second driving roller The load of the drive mechanism 111 changes, and at the same time, the transport speed of the recording paper also fluctuates rapidly. Therefore, the transport of the recording paper s becomes unstable, and the recording paper s collides with the transport guide portion 100 as shown by a broken line in FIG. . As a result, a sudden sound is generated as shown in FIG. Such sudden sound causes noise during the use of an image forming apparatus such as a copier or a printer, and is not preferable while further silencing is desired in offices and the like.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to transfer a sheet-like member such as a recording sheet in an image forming apparatus or the like even when the conveying speed or the conveying load changes. An object of the present invention is to provide a transport device that transports in a stable state and does not generate vibration or sudden sound.

[0005]

In order to achieve the above object, a sheet-like member conveying apparatus according to the present invention comprises: a rotary drive source;
A pair of roller members that convey the sheet-shaped member in between, a rotation transmitting unit that transmits rotation from the rotation drive source to the roller member, a load unit that applies a load to the rotation transmission unit, and the load unit Load changing means for changing the load at a predetermined timing.

According to the present invention, the sheet-like member is sandwiched between the pair of roller members in a state where the load is applied to the rotation transmitting means for transmitting the rotation from the rotary drive source to the pair of roller members by the load means. When the sheet is conveyed, for example, when the conveyance speed or the conveyance load increases, the load of the load unit can be changed, so that the roller member can be rotationally driven in a more braked state, and the sheet member can be stably conveyed. . Thus, it is possible to prevent the occurrence of vibrations and sudden sounds when the transport speed or the transport load is changed.

[0007] Further, it is possible to further comprise a detecting means for detecting the predetermined timing. Thereby, the load of the load means can be changed at a predetermined timing.

[0008] The detecting means may include a sensor for detecting that the sheet-shaped member has reached a predetermined position. Such a sensor can be composed of, for example, a reflection-type or transmission-type photointerrupter. By arranging the sensor near the upstream side or the downstream side of the first roller pair, the sheet-like member is moved immediately before the sheet member enters the roller member. Alternatively, it is possible to take a timing at the time of changing the load of the load means immediately after coming out of the apparatus, and it is possible to change the transport load with good timing. Further, the detection means can be arranged near the upstream or downstream side of the second roller pair, and can detect the rear end of the conveyed sheet member. This makes it possible to take the timing of changing the load of the load means.

The detecting means may be configured to detect a change in the load of the rotary drive source. This allows
When the input current of the rotary drive source changes due to a change in the transfer load, it is possible to take a timing when the load of the load unit is changed in accordance with the change in the transfer load, and to change the transfer load with good timing. Can be.

[0010] Further, the load by the load means can be configured to decrease for a predetermined period from the predetermined timing. Thus, during the period in which the transport load rises and fluctuates during the transport of the sheet member, the increased transport load can be kept constant, so that the transport of the sheet member can be stabilized.

Further, the rotation transmitting means has a rotation shaft,
The load means may be configured to apply a load to the rotating shaft.

[0012] The rotation transmitting means may include a gear, and the load means may apply a load to the gear.

[0013] The rotation transmitting means may include a winding transmission mechanism comprising a rotating body and a rotating belt, and the load means may apply a load to the rotating body.

Further, in addition to the above-mentioned load device, a tension control means for changing the tension of the rotating belt in the winding transmission mechanism can be provided. By changing the tension of the rotating belt by the tension control means, the braking state of the roller member by the load means can be further enhanced, and the conveyance of the sheet-like member can be further stabilized, thereby preventing the occurrence of vibration and sudden sound. The effect can be further improved.

Further, the load means may be configured to press a friction member against the rotating body, the side surface of the gear, or the rotating shaft. According to this configuration, the load of the load means can be applied to the rotating body or the rotating shaft by a frictional force generated between the friction member and the rotating body, the side surface of the gear, or the rotating shaft during rotation. In addition, the load can be changed by changing the frictional force.

In this case, the load means may include a drive means for operating the friction member and changing the pressing thereof at a predetermined timing. Thus, the load of the load means can be changed.

Further, the driving means may include a cam member, and the load means may be operated at the predetermined timing by the rotation of the cam member by the driving means.
Further, if the actuation source of the load means is a rotary drive source, this drive means can be omitted, and the predetermined timing can be adjusted by, for example, changing the cam surface shape of the cam member.

The pair of roller members can be driven to rotate at a high speed after receiving the conveyed sheet member. Such high-speed rotation of the sheet-like member by high-speed rotation is necessary to increase the line speed and increase productivity. However, when a load is applied at the time of high-speed transfer, particularly at the time of high-speed transfer, the transfer of the sheet-like member is not sufficient. As described above, according to the transport device of the present invention, the transport of the sheet-shaped member can be stabilized even at high speed rotation, so that the noise can be reduced without reducing productivity in an image forming apparatus or the like. Can be planned.

[0019] In this case, the second side is located upstream of the roller member.
A pair of roller members, a third pair of roller members on the downstream side, respectively, the second roller member idles when the roller member rotates at a high speed, and the third roller member rotates the sheet-shaped member. After receiving, the rear end of the sheet-like member can be configured to pass through the second roller member. In such an operation, the conveyance of the sheet-shaped member is likely to be unstable, but according to the conveyance device of the present invention as described above, the conveyance of the sheet-shaped member can be stabilized.

Since an image forming apparatus such as a printer or a copier has the above-mentioned sheet-like member conveying device, sudden sound and vibration in the image forming apparatus can be reduced, so that a more silent image forming apparatus can be realized.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view schematically showing a transport device according to the present embodiment. In order to transfer and form a toner image on a sheet-like member on the photosensitive drum 18, this transport device transfers a sheet-like member S such as recording paper from a lower paper feed unit (not shown) in the figure to an upper photosensitive member. Drum 18
It is configured to be transported.

The transfer device shown in FIG.
And a first driven roller 12, and a second driving roller 21 and a second driven roller 22 disposed upstream of the first conveying roller pair 1. A second transport roller pair 2, a third transport roller pair 3 including a third drive roller 31 and a third driven roller 32 disposed downstream of the first transport roller pair 1, A sheet-like member S is provided between these transport roller pairs 2, 1, and 3.
The transport guide paths 14 and 15 are formed, respectively, which pass when the paper is guided upward while being guided. The transport guide paths 14 and 15 are formed between guide members 91 and 92 and 93 and 94, respectively, which are arranged to oppose each other. The sheet-shaped member S is sandwiched between the driving roller and the driven roller, and is conveyed while rotating the driven roller by the rotation of the driving roller.

The sheet-like member S is fed from the paper feed section to the second roller pair 2 through the guide section 13 by the rollers 10. The sheet-like member from the third roller pair 3 passes through the conveyance guide path 16, the rollers 41 and 42, and the conveyance path 17, and rotates in the direction of arrow r.
Is transported in the direction of the arrow h and sent to the lower portion of the photosensitive drum 18 while taking the timing with the rotation of. In the case of manual paper feed, the sheet-like member is provided by the manual feed guide 16.
a to the conveyance guide path 16.

Each of the drive rollers 11 and 12 of the transport device of FIG.
A driving mechanism for driving the motors 1 and 31 will be described with reference to FIG. In the drive mechanism of FIG. 2, the rotation from the motor 23 drives each drive roller via each of the gear mechanisms 24, 25, 27, the belt mechanism 26, and the like. The rotation of the motor 23 is transmitted to the rotating shaft c via a rotating shaft a (the center line is shown in FIG. 2, the same applies hereinafter), a pair of gear mechanisms 24, a rotating shaft b and a pair of gear mechanisms 25.

As shown in FIG. 2, a third drive roller 31 is connected to the rotation shaft c, and is driven to rotate by rotation of the rotation shaft c. Belt mechanism 26 as winding transmission mechanism
Is a pair of rotating discs 26 spaced apart from each other.
b, 26c, and a belt 26a wound between the rotating disks 26b, 26c so as to be wound around the side peripheral surface thereof.

In the belt mechanism 26, when the rotating disk 26c is rotated by the rotation of the rotating shaft c, the other rotating disk 26b is rotated by the belt 26a. The first drive roller 11 is connected to the center axis d of the rotating disk 26b, and is driven to rotate by the rotation of the rotating axis d.
In addition, the rotation of the center axis d rotates the rotation axis e via the gear mechanism 27 including a plurality of gears. The rotating shaft e is connected to a rotating shaft f via a clutch mechanism 28.
The second drive roller 21 is connected to the rotation shaft f. When the rotation shafts e and f are connected by the operation of the clutch mechanism 28, the rotation of the rotation shaft e causes the second drive roller 21 to rotate.
Rotates. As described above, when the motor 23 rotates, each of the drive rollers 11, 21, 31 is rotationally driven.

Next, a first example of a load device provided in the above-described transport device will be described with reference to FIG. FIG.
FIG. 3 is a perspective view showing a load device for applying a pressing force to a rotating disk body 26b of the belt mechanism 26 in FIG. 3 includes a support member 39 fixed to a main body (not shown).
An elastic member 38 supported above, a friction member 37 pressed against the flat side surface 26d of the rotating disk 26b by the elastic body 38 via the flat plate 40, and a friction member 3
And an actuator 35 that operates a rod-shaped contact member 35a that contacts the flat plate 40 so as to separate the 7 from the flat side surface 26d.

The elastic member 38 is formed of a flat spring-shaped member, and has a curved portion 38a having an arc shape and a flat portion 38b protruding from the tip of the curved portion 38a and provided so as to oppose the flat side surface 26d of the rotating disk 26b. And Flat part 38
The friction member 37 is stuck to b.

The operation of the load device shown in FIG. 3 will be described. In the state shown in FIG. 3, the friction member 37 is pressed against the flat side surface 26d of the rotating disk 26b by the elastic force of the curved portion 38a of the elastic member 38. When the belt mechanism 26 operates in this state, a frictional force is generated between the friction member 37 and the flat side surface 26d during the rotation of the rotating disk 26b, and a load is applied to the belt mechanism 26 by the frictional force.

Next, the operation of changing the load by the friction member 37 will be described. When an instruction signal is sent from the control unit 36a to the drive unit 36 according to a detection signal from a detection unit described later, the drive unit 36 operates the actuator 35. The actuator 35 displaces the plane plate 40 by protruding the contact member 35 a in the x direction and abutting the contact member (plane plate) 40. This flat plate 40
, The friction member 37 and the flat portion 38b resist the elastic force directed toward the flat side surface 26b of the curved portion 38a.
Move in the direction away from 6d. Thereby, the frictional force can be reduced, and the load on the belt mechanism 26 by the frictional member 37 can be reduced.

Therefore, the load can be changed by controlling the amount of protrusion of the contact member 35a from the actuator 35. Further, the friction member 37 is connected to the flat side surface 2.
When it is completely separated from 6d, the load is released and a no-load state is set. The actuator 35 can be constituted by a linear control actuator or an electromagnetic clutch and a return spring. When the contact member 35a is in contact with the contact portion 40 and the load is reduced or no load is applied, the contact member 35a may be retracted by the actuator 35 in a direction opposite to the x direction by another detection signal. it can. Thus, the load state can be restored. Further, the load device of FIG. 3 may be provided on the rotating disk body 26c side of FIG. 2, or may be provided on the gear mechanisms 25 and 27 and the rotating shafts c and d.

Next, a second example of the load device is shown in FIG.
This will be described below. FIG. 4 is a perspective view showing a load device that applies a load to the rotating shaft 43 connected to the rotating disk 26b of the belt mechanism 26 in FIG. The load device of FIG.
A load part 45 is attached to a fixing plate 44 fixed to a main body (not shown), and a rotary shaft 43 is inserted into a through part formed at the center of the load part 45. In the load state, the rotating shaft 43 rotates while receiving a load in the through portion of the load portion 45. As a method of applying such a load, there are a known electromagnetic method, a friction method, a powder method, and a hysteresis method which are operated by external driving.

The operation of the load device shown in FIG. 4 will be described.
When the control unit 46a receives the detection signal in the load state, it sends an instruction signal to the drive unit 46, and the drive unit 46 changes the load on the load unit 45 and reduces the load on the rotating shaft 43. Thus, during the rotation of the rotating disk 26b, for example, in the case of the friction type, the peripheral surface 43a of the rotating shaft 43 and the load portion 45
The frictional force generated between the inner peripheral surface and the inner peripheral surface of the belt mechanism is reduced, and the load applied to the belt mechanism 26 is reduced. Note that the load unit 45 can be operated again by another detection signal to return to the load state. Further, the load device of FIG. 4 may be provided on the rotating shaft c of FIG.

Next, a description will be given, with reference to FIG. 5, of a detection apparatus which detects the timing of a load and generates and sends a detection signal to the load apparatus as shown in FIGS. The detector of FIG. 5 includes a photo-interrupter-type sensor disposed downstream of the first roller pair 1 shown in FIG.
This detects the leading end of the sheet-like member immediately after the sheet-like member exits. The detecting device shown in FIG. 5 includes a light emitting element 19 disposed downstream of the first driving roller 11 and a light emitting element 19 near the first driven roller 12 so as to oppose the light emitting element 19 with the conveyance guide path 15 therebetween. It includes a light receiving element 20 arranged on the downstream side, and a detection unit 33 that generates a detection signal based on a signal from the light receiving element 20 and controls the light emitting element 19.

The detection operation of the detection device shown in FIG. 5 will be described. In the transport device of FIG.
The sheet-like member S conveyed from the conveyance guide path 14 in the direction of the arrow V1 enters the first roller pair 1, and the leading end ST of the sheet-like member moves to the first roller pair 1 as shown by the dashed line in FIG. As soon as it exits, it is located between the light-emitting element 19 and the light-receiving element 20, so that light from the light-emitting element 19 is blocked. As a result, the signal from the light receiving element 20 changes, and this change is detected by the detection unit 33 to generate a detection signal.

As described above, the detection signal generated at the timing immediately after the leading end ST of the sheet-like member comes out of the first roller pair 1 is determined by the control unit 36a or 46 shown in FIG.
a, the load applied by the load device is changed, and the load applied to the belt mechanism can be reduced.

In FIG. 5, the transmission type photo-interrupter type is used as the position detection sensor, but the same detection is performed by detecting the reflected light from the leading end ST of the sheet member using the reflection type photo-interrupter type sensor. A signal can be generated. Further, this position detection sensor may be arranged near the upstream side. In addition, the same detection means is used in the second
May be arranged upstream or downstream of the roller pair 2.

Next, the operation of the transfer device having the above-described load device shown in FIG. 3 or 4 and the detection device shown in FIG. 5 will be described with reference to FIG. FIG. 6 shows a change in the transport load over time when the load is not applied by the load device (a), a change in the load applied by the load device over time (b), and a load by the load device during the transport of the sheet-like member. FIG. 3 schematically shows the time-varying state (c) of the transport load in the case of FIG. Therefore, FIG. 6 (a) corresponds to FIG.
And times t1, t2 and t4 in both figures represent the same time. The scale of the vertical axis is different in each figure.

In the transport state, the load device normally applies a load to a rotating body such as the rotating disk 26b of the belt mechanism and its rotating shaft 43 as shown in the substantially flat portion on the left in FIG. 6B. Now, immediately after the sheet-like member S conveyed from the second roller pair 2 through the conveyance guide path 14 in FIG. 2 enters the first roller pair 1 at time t1 and exits,
When the tip ST is detected as shown in FIG. 5, the load device operates. As a result, the load device becomes as shown in FIG.
The load is reduced in a relatively short time until time t2. As a result, as shown in FIG. 6 (a) in the conventional case, the transfer load which is high and changes considerably is shown in FIG. 6 (c).
And the fluctuation of the transport load can be reduced. At the same time, at time t1, the clutch mechanism 28 of FIG. 2 is simultaneously operated to interrupt the power transmission to the second drive roller 21, and the second roller pair 2 idles, but the belt mechanism 26 is in a state of being well braked. , The fluctuation of the transport load is suppressed, and the transport of the sheet-shaped member S is stabilized.

In order to increase the conveying speed of the sheet-shaped member S, the first drive roller 1 is driven after a predetermined time has passed since the detection signal was issued from the position detection sensor in FIG.
1 is rotated at a higher speed, and the transport speed of the sheet-like member increases. At this time, the transport of the sheet-like member tends to be unstable due to the speed fluctuation in the conventional apparatus, but in the present transport apparatus, the transport is performed as described above. Since the state is stable, the sheet-like member does not collide with the guide member and does not generate vibration or sudden sound unlike the related art.

When the sheet-like member S is further conveyed in the V direction and the leading end of the sheet-like member S enters the third roller pair 3 at time t3, and the rear end passes through the second roller pair 2 at time t4, Since the load on the first drive roller 11 changes and at the same time the conveyance speed of the sheet-like member also fluctuates rapidly, the conveyance of the sheet-like member tends to be unstable in the conventional apparatus, but in the present conveyance apparatus, as described above, Since the conveyance state is stable, the sheet-like member does not collide with the guide member and does not generate vibration or sudden sound unlike the related art.

It is necessary to rotate the first drive roller 11 at high speed to increase the conveying speed of the sheet-like member in order to increase the line conveying speed and to increase the productivity. While the conveyance of the members is likely to be unstable, according to the present conveyance device as described above, the conveyance of the sheet-like member can be stabilized even at the time of high-speed conveyance, so that the productivity is not reduced in an image forming apparatus or the like. Noise can be reduced. As described above, in an image forming apparatus such as a copier or a printer in which the present transport apparatus is incorporated, it is possible to prevent the occurrence of vibration or sudden sound that causes noise, and to contribute to a reduction in noise in an office or the like used in OA equipment. .

Next, another detecting device will be described with reference to FIG. In the detection device shown in FIG. 6, when the transport load changes as shown in FIG. 6A, for example, the current flowing through the motor 23 in FIG.
As shown in (a), the detection signal is generated when it increases and reaches a predetermined level. This detection device includes a current level detection unit 34 for detecting the level of the input current of the motor 23 as shown in FIG. 7B, and when the input current increases and reaches the level TL of FIG. Occurs. When the load current of the motor 23 decreases below the level TL 'as shown in FIG. 7C, another detection signal is generated. The detection signal is sent to each control unit of the load device as described above. For example, the level TL of the input current can be set to reach near time t1 in FIG. 6, and the level TL ′ can be set to a time tx between times t4 and t5 in FIG.
Can be set to reach. Thereby, the load change timing in the load device of FIG. 3 or FIG. 4 can be detected as in the case of FIG.

Next, a tension control device for changing the tension of the belt of the belt mechanism in the load device as shown in FIGS. 3 and 4 to further improve the effect of the load will be described with reference to FIG. FIG. 8 shows the belt mechanism 26 of FIG.
3A and 3B are a side view and a perspective view of a tension control device added in FIG. The tension control device of FIG. 8 changes the belt tension by pressing the roller 46 against the belt 26a of the belt mechanism 26.

The tension control device shown in FIG. 8 includes a large-diameter roller 46 provided at the tip of a shaft 47, a slide member 45 having the shaft 47 connected at one end, and a slide member fixed to a main body (not shown). The guide member 48 includes a guide member 48 for guiding the slide member 45, and an elastic member 49 such as a spring provided between a protrusion 45 b protruding from the other end of the slide member 45 and the protrusion 48 b of the guide member 48. The elastic member 49 urges the slide member 45 in the direction of arrow y. Further, the slide member 45 can slide in both the k and y directions in a state where the slide part 45a protruding downward in the drawing and bent is penetrated and engaged with the elongated guide hole 48a formed in the guide member 48.

The operation of the tension control device shown in FIG. 8 will be described. When the slide member 45 is moved in the y direction from a state in which the slide member 45 is moved in the direction of arrow k against the urging force of the elastic member 49 by a driving mechanism (not shown), the roller is moved together with the shaft 47. 47 contacts the belt 26a of the belt mechanism 26 to increase the tension of the belt 26a. When the slide member 45 moves in the direction k opposite to y, the tension of the belt 26a decreases.
Move away from a. Thus, the tension of the belt 26a can be changed according to the amount of movement of the guide member 45. The slide portion 45a of the slide member penetrates the elongated guide hole 48a of the guide member 48, and the movement is restricted at both ends of the guide hole 48a of the guide member 48 during movement. The timing of the tension change is
For example, similarly to the load device, the time can be from time t1 to t4 or t5 in FIG.

Next, another tension control device will be described with reference to FIG. FIG. 9 is a side view (a) and a perspective view (b) of the tension control device added to the belt mechanism 26 of FIG. The tension controller of FIG. 9 changes the belt tension by pressing the roller 46 against the belt 26a of the belt mechanism 26. Since the basic configuration is the same as that of FIG. The description is omitted.
In the tension control device of FIG. 9, the elastic member 49 such as a spring is configured such that the protrusion 45 c on the shaft 47 side of the slide member 45 and the guide member 4.
8 are provided between the projections 48c. For this reason,
The elastic member 49 urges the slide member 45 in the direction of arrow k. Except for this, the apparatus is the same as the apparatus in FIG. 8 and performs the same operation.

Next, the effect of reducing vibration and sudden sound in the case of the load device as shown in FIG. 3 and in the case where a tension control device as shown in FIG. 8 or FIG. 9 is added to this load device is shown in FIG.
This will be described below. A mechanism A shown in FIG. 10B schematically shows the load device of FIG. 3, and a mechanism B shown in FIG. 10C schematically shows a mechanism obtained by adding the tension control device of FIG. 8 or 9 to the mechanism A. To FIG. 10A shows the change over time of the sound pressure level in each of the mechanisms A and B. In the mechanism A, as in the case of the curve A, the sudden sound and the like can be considerably reduced at the peak time as compared with the conventional curve C. Further, in the mechanism B, the sudden sound and the like can be further reduced at the peak time as shown by the curve B. Thus, it can be seen that the effect of reducing the sudden sound is increased by adding the tension control device as shown in FIG. 8 or 9 to the load device.

Next, a method of arranging the photointerrupters 81 and 82 at a position different from that of the detecting means in FIG. 5 and controlling the transport load by a sequence different from that described in FIG. 6 will be described with reference to FIG. FIG. 11 is a side view schematically showing a transport device similar to that of FIG. 1, and the same portions are denoted by the same reference characters and description thereof is omitted. As shown in the figure, a photo interrupter 81 is arranged near the upstream side of the first conveying roller pair 1, and another photo interrupter 82 is arranged near the upstream side of the second conveying roller pair 2. Photo interrupter 8
The transmission type 1 and 82 are the same as the transmission type shown in FIG. 5, but may be the reflection type.

The operation of the example of the arrangement of the position detection sensors shown in FIG. 11 will be described. The sheet-like member S is transported along the transport guide path 14 by the second roller pair 2 and the first roller pair 1
, The photo-interrupter 81 detects the tip ST, and after a lapse of a predetermined time, the load device of FIG. 3 or FIG. 4 operates to reduce the load. The predetermined time may be a time immediately before the leading end of the sheet-shaped member passes through the first roller pair 1. At the same time, the tension control device
Reduce the tension of 6a. Next, the clutch mechanism 2 shown in FIG.
8, the transmission of rotational power to the second roller pair 2 is interrupted, and the second roller pair 2 idles,
The first roller pair 1 is rotated at a high speed, and the transport speed of the sheet member S is increased.

Next, when the photo interrupter 82 detects the trailing end of the sheet-like member S, the load device operates after a lapse of a predetermined time to increase the load again, and the tension control device again increases the tension of the belt 26a. Let it. The predetermined time can be a time immediately before the rear end of the sheet-shaped member S passes through the second roller pair 2. By controlling in this way, the same effect as in FIG. 6 can be obtained.

It should be noted that the timing signal for the disconnection is obtained from the clutch mechanism 28 in FIG. 2, and the load by the load device can be reduced after a lapse of a predetermined time from the timing. Also, if you know the size of the sheet-like member,
The load by the load device can be increased after a lapse of a predetermined time from the time when the clutch mechanism 28 is operated or the time when the photo interrupter 81 is detected. In this case, the photo interrupter 82 in FIG. 11 may be omitted.

Next, FIG. 12 shows a third example of the load device.
This will be described below. The load device of FIG. 12A applies a load by pressing a friction member 55 against a peripheral side surface 50a of a rotating cylindrical portion 50 protrudingly provided on a flat side surface 26d of a rotating disk body 26b of the belt mechanism 26 of FIG. Is added. The load device includes a rotating member 52 having first to third extending portions 52a, 52b, and 52c that rotate about the rotation shaft 51 and extend radially from the rotation shaft 51 at substantially equal distances. The rotating column portion 5 is attached to the mounting portion 52d at the tip of the extension portion 52a.
The rotation member 52 is attached between the tip of the second extending portion 52b and the main body side 90 in the rotation direction of the arrow n, with the friction member 55 stuck to oppose the peripheral side surface 50a. An elastic member 54 such as a biasing spring and an actuator 53 such as an electromagnetic solenoid or a linear control actuator attached to the tip of the third extension 52c via a drive shaft 53a are provided.

In the state shown in FIG. 12A, the drive shaft 53a of the actuator 53 is displaced in the direction opposite to the arrow m, and the rotating member 53 is rotated in the direction opposite to the arrow n against the urging force of the elastic member 54. , The friction member is pressed against the peripheral side surface 50a of the rotating cylindrical portion 50, and a load is applied to the belt mechanism 26 by the frictional force generated between the peripheral side surface 50a and the friction member 55. Here, when the actuator 53 operates based on the detection signal from the detection device as shown in FIG. 5 or FIG.
As a result, the friction member 55 moves in a direction away from the peripheral side surface 50a, and the frictional force therebetween decreases. According to the load device of FIG. 12A, the same effect as that of the load device of FIG. 3 can be obtained. The load can be changed by controlling the amount of protrusion of the drive shaft 53a from the actuator 53. The friction member 55 is connected to the cylindrical portion 5.
It may be configured to be pressed against the flat side surface of zero.

The actuator 5 of the load device as described above
FIG. 12 (b) shows a control method of the electromagnetic solenoid of FIG.
This will be described with reference to (c). By performing pulse width modulation (PWM) on the voltage applied to the electromagnetic solenoid as shown in FIG. 12 (c), the load from the load device is controlled so as to increase as shown in FIG. 12 (b). In addition, it can be controlled so as to be inclined when the load amount is reduced. By such control, for example, a load is not suddenly applied to the belt mechanism 26, so that it is possible to contribute to stable conveyance of the sheet-shaped member.

Next, a fourth example of the load device will be described with reference to FIG. The example of FIG. 13 has substantially the same configuration as that of FIG. 12, except that an elastic member 58 such as a leaf spring is arranged between the rotating member and the friction member. The same parts as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

The rotating member 57 of the load device shown in FIG. 13 rotates about a rotating shaft 59 and is formed in a substantially isosceles triangular shape.
The extending portion 57a of the acute angle portion is connected to the elastic member 60, and the extending portion 57b of the other acute angle portion is connected to the drive shaft 53a of the actuator 53. An elastic member 58 is attached to the obtuse angle portion 57c, and a friction member 55 is attached to the other end of the elastic member 58. The load device of FIG. 13 operates similarly to the device of FIG.
As a result, the friction member 55 and the peripheral side surface 50a of the rotating column portion 50 are formed.
And the frictional force between the load device and the load device can be changed smoothly.
It contributes to stable conveyance of the sheet member.

Next, a fifth example of the load device will be described with reference to FIG. The example of FIG. 14A has almost the same configuration as that of FIG. 12, but uses a motor 65 as an actuator.
The variation of the load is performed by a cam mechanism. The same parts as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted.

The third extending portion 52 of the rotating member 52 shown in FIG.
A rotating member 63 is rotatably provided at the end of the portion c. The rotation of the motor 65 causes the cam member 63 to rotate around the rotating shaft 61a via a speed reduction mechanism (not shown). By the cam mechanism constituted by the rotating member 63 and the cam member 61, the rotating member 52 can be rotated in a direction in which the friction member 55 contacts the peripheral side surface 50a and in a direction in which the friction member 55 separates. The cycle of applying a load can be controlled by the shape of the cam member 61, the rotation speed of the rotating shaft 61a, and the like, and the amount of load can be adjusted by the shape of the cam member 61.

For example, by rotating the cam member 61 as shown in FIG. 12B, the load by the load device shown in FIG. 12A can be varied as shown in FIG. Thereby, similarly to FIG.
The frictional force between the rotating member 50 and the peripheral side surface 50a of the rotating cylindrical portion 50 can be changed gradually, and the load from the load device can be changed smoothly, thereby contributing to stable conveyance of the sheet-shaped member. . In this load device, the elastic member 54 is used.
May be omitted. Further, in this example, the actuator can be the drive mechanism of FIG.

Next, a sixth example of the load device will be described with reference to FIG. The example of FIG. 15 has substantially the same configuration as that of FIG. 12, except that when the rotation angle of the cam member 61 is small, the cam member is moved by the actuator so that the variation range of the load amount can be increased. The same parts as those in FIG. 12 are denoted by the same reference numerals, and description thereof will be omitted. FIG.
The load device of No. 3 connects the cam member 61 to a rod member 62 protruding from an actuator 64 such as an electromagnetic solenoid or a linear control actuator.
The cam member 61 is moved by the displacement in both directions indicated by the arrows in FIG. By this movement, the friction member 55 is moved to the peripheral side surface 50a.
The rotating member 52 can be rotated in a direction in which the rotating member 52 comes into contact with and away from the cam member 61, and at the same time, the amount of the rotating member 52 can be increased.

[0062]

According to the present invention, when a sheet-like member is conveyed in an image forming apparatus or the like, the sheet-like member is conveyed in a stable state when the conveying speed is changed or when the conveying load is changed. It is possible to provide a transport device that does not generate sudden sound. This makes it possible to provide a more silent image forming apparatus.

[Brief description of the drawings]

FIG. 1 is a side view schematically showing a transfer device according to an embodiment.

FIG. 2 is a perspective view showing a driving mechanism for driving each driving roller shown in FIG.

FIG. 3 is a perspective view showing a first example of a load device that can be configured in the transfer device of FIG. 1;

FIG. 4 is a perspective view showing a second example of a load device that can be configured in the transfer device of FIG. 1;

FIG. 5 is a side view similar to FIG. 1, showing a first example of a detecting device that can be configured in the transport device of FIG. 1;

6A and 6B are diagrams illustrating an operation of applying a load by a load device in the transfer device of FIG. 1; FIG. 6A is a diagram illustrating a time change of a transfer load when no load is applied by the load device; Time change diagram of the load applied to the body (b),
FIG. 7C is a time change diagram (c) of the transport load when there is a load by the load device.

FIGS. 7A and 7B are diagrams showing a second example of the detection device which can be configured in the transport device of FIG. 1, and show diagrams (a) and (c) showing a time change of an input current of a motor and a block diagram (b). ).

8 is a side view (a) and a perspective view (b) of a belt tension control device that can be configured in the belt mechanism of the drive mechanism in FIG.

9 is a side view (a) and a perspective view (b) of another belt tension control device that can be configured in the belt mechanism of the drive mechanism in FIG. 2;

10 is a diagram illustrating the sudden sound / vibration when the load device of FIG. 3 is configured in the transfer device of FIG. 1 (mechanism A) and when the tension control device of FIG. 8 or 9 is added to the mechanism A (mechanism B). It is a figure for demonstrating the reduction effect, The time change (a) of the sound pressure level about mechanism A, B and a conventional example, the side view (b) which shows the outline of mechanism A, and the side which shows the outline of mechanism B. Figure (c)
It is.

11 is a side view showing an example in which a photo-interrupter as a detection unit is arranged at a position different from that in FIG. 5 in the transporting device of FIG.

12A is a side view showing a third example of a load device that can be configured in the transfer device of FIG. 1, FIG. 12B is a diagram showing a change in load amount of the load device with time, and FIG. FIG. 7C is a diagram illustrating an example of a voltage waveform.

FIG. 13 is a side view showing a fourth example of a load device that can be configured in the transfer device of FIG. 1;

14A is a side view showing a fifth example of a load device that can be configured in the transfer device of FIG. 1, FIG. 14B is a diagram showing a change over time of a rotation angle of a cam member of the load device, and FIG. FIG. 7C is a time change diagram of the load amount due to a change in the rotation angle of FIG.

FIG. 15 is a side view showing a sixth example of the load device that can be configured in the transfer device of FIG. 1;

FIG. 16 is a side view of a conventional transport device.

17A and 17B are diagrams for explaining the problems of the conventional transfer device of FIG. 16; FIG. 17A is a time change of a transfer load, FIG. 17B is a time change of a transfer speed, and FIG. ).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st roller pair 2 2nd roller pair 3 3rd roller pair 11,21,31 1st, 2nd and 3rd drive roller 12,22,32 1st, 2nd and 3rd driven roller 14, 15 conveyance guide path 18 photoreceptor drum 19 light emitting element (detecting means) 20 light receiving element (detecting means) 23 motor 26 belt mechanism (wrapping transmission mechanism) 26a rotating belt 26b, 26c rotating disk 26d flat rotating disk Side surface 28 Clutch mechanism 33 Detecting unit (detecting unit) 34 Current level detecting unit (detecting unit) 35 Actuator (driving unit) 37, 55 Friction member 38 Elastic member 43 Rotating shaft of rotating disk 45 Load unit 47 Round of tension control device Rod 50 Rotating cylindrical portion 50a Peripheral side surface of rotating cylindrical portion 52, 57 Rotating member 53, 64 Actuator 58 Elastic member 61 Cam member 81, 82 Photointerrupters (detection means) 91, 92 Guide members a to f Rotation axis S Sheet-shaped member ST Tip of sheet-shaped member

──────────────────────────────────────────────────続 き Continuing on the front page (51) Int.Cl. ⁶ Identification code FI G03G 15/00 518 G03G 15/00 518 (72) Inventor Jun Atsushi 2970 Ishikawacho, Hachioji-shi, Tokyo Konica Corporation ( 72) Inventor Hirofumi Sasaki 2970 Ishikawacho, Hachioji City, Tokyo Inside Konica Corporation

Claims (15)

[Claims] A rotation driving source; a pair of roller members for conveying the sheet-like member in between; a rotation transmission unit for transmitting rotation from the rotation driving source to the roller member; A sheet-like member transport device comprising: a load unit that applies a load; and a load changing unit that changes a load of the load unit at a predetermined timing. 2. The sheet-like member conveying device according to claim 1, further comprising a detection unit that detects the predetermined timing. 3. The sheet-like member conveying device according to claim 2, wherein said detecting means includes a sensor for detecting that the sheet-like member has reached a predetermined position. 4. The sheet-like member conveying device according to claim 2, wherein said detecting means detects a change in load of said rotary drive source. 5. The sheet-like member conveying apparatus according to claim 1, wherein the load by said load means is reduced for a predetermined period from said predetermined timing. 6. The rotation transmitting means includes a rotating shaft, and the load means applies a load to the rotating shaft.
The sheet-like member conveying device according to any one of the above. 7. The sheet-like member conveying apparatus according to claim 1, wherein said rotation transmitting means includes a gear, and said load means applies a load to said gear. 8. The sheet-like member conveyance according to claim 1, wherein said rotation transmitting means includes a winding transmission mechanism comprising a rotating body and a rotating belt, and said load means applies a load to said rotating body. apparatus. 9. The sheet conveying apparatus according to claim 8, further comprising a tension control unit for changing a tension of the rotating belt. 10. The sheet-like member conveying device according to claim 6, wherein said load means is configured to press a friction member against said rotating shaft, said gear or said rotating body. 11. The sheet-like member conveying apparatus according to claim 10, wherein said load means includes a drive means for operating said friction member and changing its pressing at a predetermined timing. 12. The sheet conveying device according to claim 11, wherein said driving means includes a cam member, and said load means operates at said predetermined timing by rotation of said cam member by said driving means. 13. The sheet-like member conveying apparatus according to claim 1, wherein the pair of roller members are driven to rotate at a high speed after receiving the conveyed sheet-like member. 14. A second pair of roller members are provided on the upstream side of the roller member and a third pair of roller members are provided on the downstream side thereof, and the second roller member is idle when the roller member rotates at a high speed. 14. The sheet-like member conveying device according to claim 13, wherein a rear end of the sheet-like member passes through the second roller member after the third roller member receives the sheet-like member. 15. An image forming apparatus comprising the sheet-like member conveying device according to claim 1.