JP2012025550A - Conveyance device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying device in which crashing sound produced as the leading end of a recording medium bumps into resist rollers is reduced without decreasing the print productivity, and to provide an image forming apparatus.SOLUTION: The conveyance device includes resist rollers 17, 18 which stop rotating to cause the tip end of a recording medium to bump into the resist rollers, and start rotating after a certain timing to convey the recording medium P toward an image forming unit 7. The conveyance device also includes a braking member 31 disposed upstream of the conveyance direction of the recording medium P relative to the resist rollers 17, 18, and which is configured to, before the tip end of the recording medium P bumps into the resist rollers 17, 18, move to abut on the recording medium P to thereby brake the speed of the recording medium P.

Description

  The present invention relates to a conveyance device that conveys a recording medium toward an image forming unit, and an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine including the same.

  Conventionally, in an image forming apparatus such as a copying machine or a printer, an image carried on an image carrier such as a photosensitive drum or an intermediate transfer belt is accurately transferred to a desired position on a recording medium by an image forming unit. Further, after correcting the skew (skew) of the recording medium by abutting the leading edge of the recording medium against the registration roller (registration roller pair) in the rotation stopped state, the recording medium is directed to the image forming unit by the rotating registration roller. There is known a technique for transporting in a timely manner (for example, see Patent Document 1).

In such an image forming apparatus, there is a known problem that an irritating impact sound is generated when the leading edge of a recording medium hits a registration roller.
In order to solve such a problem, Patent Document 1 and the like disclose a technique for reducing the conveyance speed of a recording medium when the recording medium collides with a registration roller.

Since the technology disclosed in Patent Document 1 described above reduces the conveyance speed of the recording medium when the recording medium collides with the registration roller, the generation of impact sound when the leading edge of the recording medium hits the registration roller is reduced. Can be expected. However, since this technique reduces the conveyance speed of the recording medium, it reduces print productivity in the image forming apparatus.
Such a problem cannot be ignored particularly in a high-speed image forming apparatus in which a recording medium is conveyed at a high speed.

  The present invention has been made to solve the above-described problems, and can reduce the generation of impact sound when the leading edge of a recording medium hits a registration roller without reducing print productivity. And providing an image forming apparatus.

  According to a first aspect of the present invention, there is provided a transport apparatus for transporting a recording medium toward an image forming section for forming an image on the recording medium, the recording medium being connected to the image forming section. The rotation drive is stopped and the front end of the recording medium is abutted, and then the rotation drive is started at a predetermined timing to convey the recording medium toward the image forming unit. The registration roller is disposed upstream of the registration roller in the conveyance direction of the recording medium, and moves so that the front end of the recording medium comes into contact with the recording medium before contacting the registration roller. And a braking member that brakes the speed.

  According to a second aspect of the present invention, in the conveying device according to the first aspect, the braking member is separated to a position where the braking member does not contact the recording medium when the leading end of the recording medium passes through the position. Then, before the leading edge of the recording medium comes into contact with the registration roller, it moves so as to contact the recording medium, and after a predetermined time has elapsed, before the rotation of the registration roller is started, It is separated to a position where it does not contact the recording medium.

  A conveying device according to a third aspect of the present invention is the conveying device according to the first or second aspect, further comprising a guide member for guiding a recording medium conveyed toward the position of the registration roller, The braking member is a plate-like member or roller member disposed at a position facing the guide member, and moves so as to sandwich the recording medium between the guide member and brakes the speed of the recording medium. Is.

  According to a fourth aspect of the present invention, there is provided the conveying device according to the first or second aspect, wherein the braking member is two roller members facing each other. At least one roller member moves so as to sandwich the recording medium therebetween, and brakes the speed of the recording medium.

  According to a fifth aspect of the present invention, in the conveying device according to the first to fourth aspects of the present invention, the contact surface of the braking member that contacts the recording medium is formed of an elastic material. It is a thing.

  According to a sixth aspect of the present invention, an image forming apparatus includes the conveyance device according to any one of the first to fifth aspects.

  In the present invention, since the braking member that moves so as to contact the recording medium immediately before the leading edge of the recording medium hits the registration roller is provided, the leading edge of the recording medium hits the registration roller without reducing print productivity. It is possible to provide a transport device and an image forming apparatus that can reduce the occurrence of impact noise.

1 is an overall configuration diagram illustrating an image forming apparatus according to Embodiment 1 of the present invention. FIG. 2 is a configuration diagram illustrating a conveyance device installed in the image forming apparatus of FIG. 1. FIG. 3 is a diagram illustrating a state in which a brake plate sandwiches a recording medium in the transport device of FIG. 2. It is a block diagram which shows the conveying apparatus in Embodiment 2 of this invention. FIG. 5 is a diagram illustrating a state in which the brake roller sandwiches the recording medium in the transport device of FIG. 4. It is a block diagram which shows the conveying apparatus in Embodiment 3 of this invention. FIG. 7 is a diagram illustrating a state in which a braking roller sandwiches a recording medium in the transport device of FIG. 6.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

Embodiment 1 FIG.
A first embodiment of the present invention will be described in detail with reference to FIGS.
First, the configuration and operation of the entire image forming apparatus will be described with reference to FIG.
In FIG. 1, reference numeral 1 denotes an apparatus main body of a copying machine as an image forming apparatus, 2 an original reading unit that optically reads image information of an original D, and 3 an exposure light L based on image information read by the original reading unit 2. Is exposed to the photosensitive drum 5, 4 is an image forming unit for forming a toner image (image) on the photosensitive drum 5, and 7 is a toner image formed on the photosensitive drum 5 on the recording medium P. A transfer section (image forming section) for transferring, 10 a document transport section for transporting a set document D to the document reading section 2, 12 to 14 a paper feed section for storing a recording medium P such as transfer paper, 17, Reference numeral 18 denotes a registration roller (registration roller pair) that conveys the recording medium P toward the transfer unit 7, 20 denotes a fixing device that fixes an unfixed image on the recording medium P, and 21 denotes a fixing roller installed in the fixing device 20. 22 is a pressure roller installed in the fixing device 20; It is.

With reference to FIG. 1, an operation during normal image formation in the image forming apparatus will be described.
First, the document D is conveyed from the document table in the direction of the arrow in the drawing by the conveyance roller of the document conveyance unit 10 and passes over the document reading unit 2. At this time, the document reading unit 2 optically reads the image information of the document D passing above.
Then, the optical image information read by the document reading unit 2 is converted into an electric signal and then transmitted to the exposure unit 3 (writing unit). Then, exposure light L such as laser light based on the image information of the electrical signal is emitted from the exposure unit 3 toward the photosensitive drum 5 of the image forming unit 4.

On the other hand, in the image forming unit 4, the photosensitive drum 5 is rotated in the clockwise direction in the drawing, and image information is transferred onto the photosensitive drum 5 through a predetermined image forming process (charging process, exposure process, development process). An image (toner image) corresponding to is formed.
Thereafter, the image formed on the photosensitive drum 5 is transferred onto the recording medium P conveyed by the registration rollers 17 and 18 in the transfer unit 7 as an image forming unit.

On the other hand, the recording medium P conveyed to the transfer unit 7 (image forming unit) operates as follows.
First, one of the plurality of paper feeding units 12, 13, and 14 of the image forming apparatus main body 1 is automatically or manually selected (for example, the uppermost paper feeding unit 12 is selected). To do.)
Then, the uppermost sheet of the recording medium P stored in the paper feeding unit 12 is transported toward the position of the transport path K.

  Thereafter, the recording medium P passes through a conveyance path K in which a plurality of conveyance rollers are arranged, and reaches the position of the registration rollers 17 and 18. Then, the recording medium P that has reached the positions of the registration rollers 17 and 18 is directed to the transfer unit 7 (image forming unit) at the same timing in order to align with the image formed on the photosensitive drum 5. Be transported.

After the transfer process, the recording medium P passes through the position of the transfer unit 7 and then reaches the fixing device 20 through the conveyance path. The recording medium P that has reached the fixing device 20 is fed between the fixing roller 21 and the pressure roller 22, and the image is fixed by the heat received from the fixing roller 21 and the pressure received from both members 21 and 22. The The recording medium P on which the image has been fixed is delivered from between the fixing roller 21 and the pressure roller 22 (a nip portion) and then discharged from the image forming apparatus main body 1.
Thus, a series of image forming processes is completed.

Next, with reference to FIG. 2 and FIG. 3, the conveyance device 30 that is characteristic in the first embodiment will be described in detail.
2 and 3, the transport device 30 includes transport rollers 15 and 16 (a pair of transport rollers), a guide member 19, a braking plate 31 as a braking member, and a photo along the transport path of the recording medium P. A sensor 40, registration rollers 17, 18 (registration roller pair), and the like are disposed.
The recording medium P is conveyed by the conveying device 30 toward the transfer unit 7 (the position where the photosensitive drum 5 and the transfer roller are opposed to each other) as an image forming unit that forms an image on the recording medium P. become.

  Specifically, the recording medium P that has reached the position of the transport rollers 15 and 16 from the paper feed unit via the transport path K is further transported to the positions of the registration rollers 17 and 18 while being guided by the guide member 19 (guide plate). The The recording medium P conveyed to the position of the registration rollers 17 and 18 has its leading end abutted against the registration rollers 17 and 18 whose rotation drive has been stopped, thereby correcting skew (skew correction) and vertical registration correction (conveyance). Then, the image is conveyed toward the transfer unit 7 (image forming unit) in time with the image on the photosensitive drum 5. Thus, a desired image is transferred onto the recording medium P.

  More specifically, the registration rollers 17 and 18 are a pair of rollers disposed on the downstream side in the conveyance direction of the recording medium P with respect to the transfer unit 7 (image forming unit). The registration rollers 17 and 18 are configured to be rotationally driven and stopped independently of the conveying rollers 15 and 16 by a motor (not shown). Then, by the on / off operation of the motor, as described above, after the leading end of the recording medium P hits the registration rollers 17 and 18 in a state where the rotational driving is stopped and the skew correction / longitudinal registration correction is performed, a predetermined value is obtained. The recording medium P is conveyed toward the transfer unit 7 (image forming unit) by the registration rollers 17 and 18 that have started to rotate at the timing.

Here, in the transport device 30 according to the first embodiment, a brake plate 31 as a brake member is disposed at a position upstream of the registration rollers 17 and 18 in the transport direction of the recording medium P. The braking plate 31 (braking member) moves so as to contact the recording medium P before the leading end of the recording medium P hits the registration rollers 17 and 18 (at the timing immediately before), and the recording medium This is for braking the speed of P.
Specifically, referring to FIG. 2, the braking plate 31 (braking member) is a plate-like member disposed at a position facing the guide member 19, and is moved relative to the guide member 19 by the moving mechanisms 32 to 34. It is comprised so that it may adjoin / separate. As shown in FIG. 3, immediately before the leading edge of the recording medium P hits the registration rollers 17 and 18, the braking plate 31 moves so as to sandwich the recording medium P with the guide member 19, whereby the registration roller The speed of the recording medium P that strikes 17 and 18 is braked.

More specifically, both ends of the braking plate 31 (braking member) are held by the side plates of the transport device 30 so as to be movable in the vertical direction. Further, springs (not shown) for urging the brake plate 31 upward are installed at both ends of the brake plate 31.
The moving mechanism swings in a direction away from the guide member 19, a swing plate 32 that engages the brake plate 31, a cam 33 that acts on the swing plate 32 and biases the brake plate 31 toward the guide member 19. A tension spring 34 that biases the plate 32, a drive motor 45 (stepping motor) that rotationally drives the cam 33, a position sensor (not shown) that detects the posture of the cam 33 in the rotational direction, and the like. . The swing plate 32 is held on the side plate of the transport device 30 so as to be rotatable about a support shaft 32a.
When the cam 33 is rotationally driven to the state shown in FIG. 2 by the drive motor 45 controlled by the control unit 46, the swing plate 32 urges the urging force of the tension spring 34 and the brake plate 31 upward. The braking plate 31 moves away from the recording medium P passing through the position of the braking plate 31 by moving upward to resist its own weight by the biasing force of a spring (not shown). (It is the state of FIG. 2).
On the other hand, when the cam 33 is rotationally driven to the state shown in FIG. 3 by the drive motor 45 controlled by the control unit 46, the swing plate 32 moves the urging force of the tension spring 34 and the brake plate 31 upward. The brake plate 31 is pressed against the recording medium P that is pushed downward by the cam 33 and passes the position of the brake plate 31 so as to resist the biasing force of a spring (not shown) that biases. (The state shown in FIG. 3). That is, the recording medium P is sandwiched between the brake plate 31 and the guide member 19 and the speed of the recording medium P is braked.

Hereinafter, the operation of the braking plate 31 (braking member) in the transport device 30 configured as described above will be described in detail.
First, as shown in FIG. 2, when the tip of the recording medium P passes through the position of the brake plate 31, the brake plate 31 is separated to a position where it does not contact the recording medium P.
Thereafter, immediately before the leading edge of the recording medium P hits the registration rollers 17 and 18, the brake plate 31 moves so as to contact the recording medium P. Specifically, when the front end of the recording medium P is optically detected by the photo sensor 40 disposed between the brake plate 31 and the registration rollers 17 and 18, the detection information is sent to the control unit 46. The drive motor 45 is controlled by the control unit 46, and the cam 33 is rotationally driven to the position of FIG. 3, and the recording medium P is sandwiched between the brake plate 31 and the guide member 19. As a result, immediately before the recording medium P collides with the registration rollers 17 and 18, the speed of the recording medium P is weakened, and the generation of impact sound when the leading edge of the recording medium P hits the registration rollers 17 and 18 is reduced. Will be.

  Thereafter, the recording medium P is sandwiched between the brake plate 31 and the guide member 19, and after a predetermined time (in the first embodiment, it is set to 0.1 second or less), recording is performed. The brake plate 31 is separated at a position where it does not come into contact with the medium P (a state shown in FIG. 2). Specifically, when a predetermined time (minute time) has elapsed since the leading edge of the recording medium P was optically detected by the photosensor 40, the controller 46 identifies the drive motor 45. Under the control, the cam 33 is rotationally driven to the position shown in FIG. 2, and the braking plate 31 moves away from the guide member 19 (recording medium P) (the sandwiching of the recording medium P is released). Such a separation operation of the brake plate 31 is performed before the rotational driving of the registration rollers 17 and 18 is started.

As described above, the contact / separation operation of the brake plate 31 is performed instantaneously without delaying the timing at which the rotational driving of the registration rollers 17 and 18 is started (timing for conveying the recording medium P to the transfer unit 7). Print productivity in the image forming apparatus 1 is not reduced.
Further, at the time when the recording medium P hits the registration rollers 17 and 18 (or at a timing slightly delayed from the time of hitting), the brake plate 31 is separated from the recording medium P (in a state where the recording medium P is not restrained). Therefore, the recording medium P after hitting the registration rollers 17 and 18 is moderately bent by the inertia force in the transport direction, and the skew correction and the vertical registration correction can be performed without any problem. Will be executed.
Note that the timing at which the recording medium P is sandwiched between the brake plate 31 and the guide member 19 is more immediately before the leading end of the recording medium P hits the registration rollers 17 and 18, and the effect of reducing the above-described impact sound is greater. Become. That is, after the holding of the recording medium P by the brake plate 31 and the guide member 19 is released, if the time (or distance) until the leading end of the recording medium P hits the registration rollers 17 and 18 becomes longer, the recording medium Since it hits the registration rollers 17 and 18 in a state where the speed of P is increased, the effect of reducing the above-described impact sound is reduced.

  Here, in the first embodiment, it is preferable that the braking plate 31 (braking member) is formed of an elastic material such as a rubber material on the contact surface that contacts the recording medium P. As a result, the frictional resistance when the braking plate 31 is brought into contact with the recording medium P can be increased, and the braking performance for the recording medium P is improved. , 18 is further reduced in the generation of impact sound.

  As described above, in the first embodiment, the braking plate 31 (braking member) that moves so as to contact the recording medium P immediately before the leading edge of the recording medium P abuts against the registration rollers 17 and 18 is provided. Therefore, it is possible to reduce the generation of impact sound when the leading edge of the recording medium P hits the registration roller without reducing print productivity.

In the first embodiment, the brake plate is interlocked with the timing at which the front end of the recording medium P is optically detected by the photo sensor 40 disposed between the brake plate 31 and the registration rollers 17 and 18. The recording medium P was sandwiched between the guide member 19 by moving 31.
On the other hand, a photo sensor for detecting the recording medium P is disposed upstream of the brake plate 31 (upstream in the conveyance direction of the recording medium P) to detect the recording medium P optically. After a lapse of a predetermined time (the time calculated from the transport distance from the position of the photo sensor to the position of the brake plate 31 and the transport speed of the recording medium P + α), the brake plate 31 is moved. The recording medium P can also be controlled to be sandwiched between the guide member 19 and the guide member 19.
Further, a photo sensor for detecting the recording medium P is arranged at the position of the paper feeding unit, and a predetermined time (from the position of the paper feeding unit to the position of the brake plate 31) after the paper feeding operation in the paper feeding unit is started. (The time calculated from the transport distance to reach and the transport speed of the recording medium P + α).), The brake plate 31 is moved so that the recording medium P is sandwiched between the guide member 19 and the brake plate 31. You can also
In these cases, the same effect as in the first embodiment can be obtained.

Embodiment 2. FIG.
A second embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 4 is a configuration diagram illustrating the transfer device according to the second embodiment, and corresponds to FIG. 2 according to the first embodiment. FIG. 5 is a diagram showing a state in which the braking member holds the recording medium P, and corresponds to FIG. 3 in the first embodiment.
The conveying device in the second embodiment is different from that in the first embodiment in which the braking roller 51 is used as a braking member, and the braking plate 31 is used as the braking member.

Similarly to the first embodiment, the conveying device 30 according to the second embodiment also includes conveying rollers 15 and 16 (a pair of conveying rollers), a guide member 19, a braking member 51, a photo sensor 40, and registration rollers 17 and 18. (Registration roller pair) and the like are disposed.
Here, the braking member in the second embodiment is a braking roller 51 as a roller member disposed at a position facing the guide member 19, and the recording medium P is sandwiched between the braking member 51 and the guide member 19. It is configured to move and brake the speed of the recording medium P.

  The brake roller 51 (brake member) is held by shafts at both ends thereof so as to be movable in the vertical direction on the side plate of the transport device 30 via bearings. A spring (not shown) that urges the braking roller 51 upward is installed on the bearing that holds both end shaft portions of the braking roller 51. The braking roller 51 configured as described above has the moving mechanisms 32 to 34 (the swing plate 32 is engaged with the shaft portion of the braking roller 51) configured in the same manner as in the first embodiment. ) To move up and down.

Specifically, first, as shown in FIG. 4, when the tip of the recording medium P passes through the position of the braking roller 51, the braking roller 51 is separated to a position where it does not contact the recording medium P.
Thereafter, immediately before the leading edge of the recording medium P abuts against the registration rollers 17 and 18, the braking roller 51 moves so as to contact the recording medium P. Specifically, when the front end of the recording medium P is optically detected by the photosensor 40, the detection information is sent to the control unit 46, the drive motor 45 is controlled by the control unit 46, and the cam 33 is shown in FIG. The recording medium P is sandwiched between the braking roller 51 and the guide member 19. As a result, immediately before the recording medium P collides with the registration rollers 17 and 18, the speed of the recording medium P is weakened, and the generation of impact sound when the leading edge of the recording medium P hits the registration rollers 17 and 18 is reduced. Will be.
In the second embodiment, since the recording medium P is sandwiched by using the braking roller 51, the braking roller 51 is rotated in the clockwise direction in FIG. An appropriate braking force is applied to the medium P. As a result, a braking force that is too large for the recording medium P is applied, and a problem that a jam (conveyance failure) occurs in the recording medium P being conveyed can be suppressed.

  Thereafter, after a predetermined time (in the second embodiment, it is set to 0.1 second or less) with the recording medium P sandwiched between the braking roller 51 and the guide member 19, recording is performed. The braking roller 51 is separated at a position where it does not contact the medium P (the state shown in FIG. 4 is reached). Such a separation operation of the braking roller 51 is performed before the rotational driving of the registration rollers 17 and 18 is started.

  Note that the contact surface (surface layer) that contacts the recording medium P can also be formed of an elastic material (elastic layer) such as a rubber material in the braking roller 51 (braking member) in the second embodiment. As a result, the frictional resistance when the braking roller 51 is brought into contact with the recording medium P can be increased, and the braking performance for the recording medium P is improved. , 18 is further reduced in the generation of impact sound.

  As described above, in the second embodiment, the braking roller 51 (braking member) that moves so as to contact the recording medium P immediately before the leading edge of the recording medium P hits the registration rollers 17 and 18 is provided. Therefore, it is possible to reduce the generation of impact sound when the leading edge of the recording medium P hits the registration roller without reducing print productivity.

Embodiment 3 FIG.
A third embodiment of the present invention will be described in detail with reference to FIGS.
FIG. 6 is a configuration diagram illustrating the transfer device according to the third embodiment, and corresponds to FIG. 2 according to the first embodiment. FIG. 7 is a view showing a state in which the braking member sandwiches the recording medium P, and corresponds to FIG. 3 in the first embodiment.
The conveying device in the third embodiment is different from that in the second embodiment in which one braking roller 51 is used as a braking member in that two braking rollers 51 and 52 are used as a braking member. .

Similarly to the second embodiment, the conveying device 30 according to the third embodiment also includes conveying rollers 15 and 16 (a pair of conveying rollers), a guide member 19, a braking roller 51 (braking member), a photo sensor 40, and a resist. Rollers 17 and 18 (registration roller pair) are disposed.
Here, the braking members in the third embodiment are the braking rollers 51 and 52 as the two roller members facing each other, and one of the braking members 51 and 52 has the recording medium P sandwiched between the two braking rollers 51 and 52. The brake roller 51 moves to brake the speed of the recording medium P.

  As with the second embodiment, the moving brake roller 51 (brake member) is held so that the shaft portions at both ends thereof are movable in the vertical direction on the side plate of the conveying device 30 via bearings. . A spring (not shown) that urges the braking roller 51 upward is installed on the bearing that holds both end shaft portions of the braking roller 51. Then, the upper braking roller 51 configured in this way has moving mechanisms 32 to 34 (the swing plate 32 is engaged with the shaft portion of the braking roller 51) configured in the same manner as in the first embodiment. Is moved up and down.

Specifically, as shown in FIG. 6, when the leading end of the recording medium P passes through the positions of the two braking rollers 51 and 52, the upper braking roller 51 is separated to a position where it does not contact the recording medium P. Yes.
Thereafter, immediately before the leading edge of the recording medium P hits the registration rollers 17 and 18, the upper braking roller 51 moves so as to contact the recording medium P. Specifically, when the front end of the recording medium P is optically detected by the photosensor 40, the detection information is sent to the control unit 46, the drive motor 45 is controlled by the control unit 46, and the cam 33 is shown in FIG. The recording medium P is sandwiched between the two braking rollers 51 and 52. As a result, immediately before the recording medium P collides with the registration rollers 17 and 18, the speed of the recording medium P is weakened, and the generation of impact sound when the leading edge of the recording medium P hits the registration rollers 17 and 18 is reduced. Will be.
In the third embodiment, since the recording medium P is sandwiched between two roller members (braking rollers 51 and 52), the braking rollers 51 and 52 are rotated by the speed of the recording medium P, respectively. As a result, an appropriate braking force is applied to the recording medium P. As a result, a braking force that is too large for the recording medium P is applied, and a problem that a jam (conveyance failure) occurs in the recording medium P being conveyed can be suppressed.

  After that, after a predetermined time (in the third embodiment, it is set to 0.1 second or less) with the recording medium P sandwiched between the two braking rollers 51 and 52, the recording medium is passed. The upper braking roller 51 is separated at a position where it does not contact P (the state shown in FIG. 6 is reached). Such a separation operation of the braking roller 51 is performed before the rotational driving of the registration rollers 17 and 18 is started.

  Note that the two braking rollers 51 and 52 (braking members) in the third embodiment also have contact surfaces (surface layers) that contact the recording medium P formed of an elastic material (elastic layer) such as a rubber material. Can do. As a result, the frictional resistance when the braking rollers 51 and 52 are brought into contact with the recording medium P can be increased, and the braking performance with respect to the recording medium P is improved. Generation of impact sound when hitting the rollers 17 and 18 is further reduced.

Further, in the third embodiment, only one of the two braking rollers 51 and 52 is moved, and the recording medium P is sandwiched between the two braking rollers 51 and 52.
On the other hand, only the other braking roller 52 of the two braking rollers 51 and 52 can be moved, and the recording medium P can be sandwiched between the two braking rollers 51 and 52. Further, the recording medium P may be sandwiched between the two braking rollers 51 and 52 by moving both of the two braking rollers 51 and 52.

  As described above, in the third embodiment, the braking rollers 51 and 52 (braking members) that move so as to contact the recording medium P immediately before the leading edge of the recording medium P abuts against the registration rollers 17 and 18 are provided. Therefore, it is possible to reduce the generation of an impact sound when the leading edge of the recording medium P hits the registration roller without reducing print productivity.

In each of the above-described embodiments, the present invention is applied to the conveyance device 30 installed in the monochrome image forming apparatus 1. However, the present invention is naturally applied to the conveyance device installed in the color image forming apparatus. The invention can be applied.
In each of the above embodiments, the present invention is applied to the conveyance device 30 installed in the electrophotographic image forming apparatus 1. However, the application of the present invention is not limited to this, and other methods. The image forming apparatus (for example, an ink jet type image forming apparatus) is a conveyance device, and the recording medium is timed by a registration roller toward an image forming unit that forms an image on the recording medium. Of course, the present invention can be applied to all of these transport apparatuses.
Even in those cases, the same effects as those of the above-described embodiments can be obtained.

  It should be noted that the present invention is not limited to the above-described embodiments, and within the scope of the technical idea of the present invention, the embodiments can be modified as appropriate in addition to those suggested in the embodiments. Is clear. In addition, the number, position, shape, and the like of the constituent members are not limited to the above embodiments, and can be set to a number, position, shape, and the like that are suitable for carrying out the present invention.

1 image forming apparatus body (apparatus body),
5 Photosensitive drum,
7 Transfer section (image forming section),
15, 16 transport rollers,
17, 18 Registration roller,
19 guide members,
30 transport device,
31 Brake plate (plate-like member, brake member),
32 swing plate, 33 cam, 34 tension spring,
40 Photosensor,
51, 52 Brake roller (roller member, brake member), P recording medium.

JP-A-9-175893

Claims (6)

A conveying device that conveys the recording medium toward an image forming unit that forms an image on the recording medium,
The image forming unit is disposed on the upstream side of the recording medium conveyance direction, and the rotation driving is stopped and the leading end of the recording medium is abutted. A registration roller that conveys the recording medium toward the section,
The recording medium is disposed upstream of the registration roller in the conveyance direction of the recording medium, and is moved so as to contact the recording medium before the leading edge of the recording medium hits the registration roller, thereby braking the speed of the recording medium. A braking member for
A conveying apparatus comprising:   The braking member is separated to a position where it does not come into contact with the recording medium when the leading end of the recording medium passes through the position so that the leading end of the recording medium comes into contact with the recording medium before contacting the registration roller. 2. The transport device according to claim 1, wherein the transfer device is separated to a position where it does not contact the recording medium before a rotation of the registration roller is started after a predetermined time has passed since the movement. A guide member for guiding a recording medium conveyed toward the position of the registration roller;
The braking member is a plate-like member or roller member disposed at a position facing the guide member, and moves so as to sandwich the recording medium between the guide member and brake the speed of the recording medium. The conveying apparatus according to claim 1 or 2, wherein   The braking member is two roller members facing each other, and at least one roller member moves so as to sandwich the recording medium between the two roller members to brake the speed of the recording medium. The transport apparatus according to claim 1 or 2.   The conveying device according to any one of claims 1 to 4, wherein the braking member has an abutting surface that abuts against the recording medium made of an elastic material.   An image forming apparatus comprising the transport device according to claim 1.

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