KR20100083092A - Reversely transferring unit of a printing medium and image forming apparatus including the same - Google Patents

Abstract

PURPOSE: A reversely transferring unit of a printing medium and an image forming device including the same are provided to reduce transfer time of a print media. CONSTITUTION: A plate driving unit(230) comprises an actuator(231), driving source(235) and an electronic clutch(233). The actuator rotates a guide plate. The driving source drives the actuator. The electronic clutch selectively transfers driving force of the driving source to the actuator.

Description

REVERSELY TRANSFERRING UNIT OF A PRINTING MEDIUM AND IMAGE FORMING APPARATUS INCLUDING THE SAME}

The present invention relates to a print medium reverse transfer unit and an image forming apparatus including the same, and more particularly, to a print medium reverse transfer unit and an image forming apparatus including the same, which can improve a printing speed.

An image forming apparatus is an apparatus for printing a desired image on a print medium using ink or toner, and includes a multifunction apparatus including at least one of a copier, a printer, a facsimile, a scanner, and a function thereof.

The image forming apparatus includes a print unit for printing a print medium and a stacking unit for loading a print medium printed by the print unit.

The loading unit is usually installed on the upper front side of the image forming apparatus so that a user can easily access the printed print medium.

By the way, when the print medium printed by the printing unit is transferred toward the rear portion of the image forming apparatus, it is necessary to transfer the print medium to the loading unit installed in the front portion again.

Here, when the print medium is to be transferred to the loading unit while maintaining the direction in which the printed print medium is transferred, that is, the direction toward the rear surface portion, the print medium should be U-turned toward the loading unit.

However, such a U-turn structure may increase the height of the image forming apparatus.

In addition, the U-turn structure requires a considerable time for the print medium to be discharged because the path for transferring the print medium is long.

Accordingly, it is an object of the present invention to provide a printing medium reverse transfer unit capable of miniaturizing a product and an image forming apparatus including the same.

Another object of the present invention is to provide a print medium reverse transfer unit and an image forming apparatus including the same, which can shorten a transfer time of a print medium.

Still another object of the present invention is to provide a print medium reverse transfer unit capable of switching a transfer direction of a print medium at high speed without jam, and an image forming apparatus including the same.

According to an aspect of the present invention, there is provided a printing medium reverse conveying unit of an image forming apparatus, comprising: a frame forming a first conveying path through which a printing medium is conveyed and a second conveying path crossing the first conveying path; A guide plate rotatable between a first position for supporting the print medium conveyed along the first conveyance path and a second position for redirecting the loaded print medium in the direction of the second conveyance path; And a plate driving unit including an actuator for rotating the guide plate, a driving source for driving the actuator, and an electromagnetic clutch for selectively transmitting the driving force of the driving source to the actuator. Can be achieved.

Here, the sensor unit disposed on the first transfer path; The control unit may further include a control unit for controlling the plate driving unit based on the detection result of the sensor unit.

In addition, the first driving roller for transferring the print medium to the second transfer path E; And contacting the first drive roller with the print medium therebetween when the guide plate is in the second position and spaced apart from the first drive roller when the guide plate is in the first position. can do.

The contact part may include at least one of an idle roller, a sliding part, and an elastic pad.

In addition, the contact portion may be installed on the guide plate.

The apparatus may further include a second driving roller which rotates in one direction and transfers the print medium to the first transfer path and transfers the print medium supported by the guide plate along the second transfer path.

The first driving roller and the second driving roller may be driven by the driving source.

In addition, the printing medium supported by the guide plate may further include a departure prevention unit for preventing the departure from the guide plate.

Here, the actuator may include a cam.

In addition, according to the present invention, there is provided an image forming apparatus having a main body, comprising: a printing unit accommodated in the main body and printing a print medium; A loading unit installed at an upper side of the main body, for storing a printing medium printed by the printing unit; It can be achieved by the image forming apparatus, characterized in that it comprises the above-described print medium back transfer unit, which transfers the print medium printed by the print unit to the stacking unit.

Here, the first transfer path may be provided to connect the printing unit and the guide plate, and the second transfer path may be connected to the guide plate and the loading unit.

And, the print medium reverse transfer unit may be provided to be detachable to the main body.

According to the printing medium reverse transfer unit and the image forming apparatus including the same configured as described above has the following advantages.

First, the product can be miniaturized.

Second, the transfer time of the print media can be shortened. That is, it is possible to transfer the print medium at high speed, thereby improving the printing speed.

Third, the conveying direction of the print medium can be switched at high speed without jamming.

Hereinafter, with reference to the accompanying drawings will be described in detail a print medium reverse transfer unit and an image forming apparatus including the same according to a preferred embodiment of the present invention.

As shown in FIG. 1, the image forming apparatus 100 according to the present invention includes a printing unit 120 accommodated in the main body 101 and printing a print medium; A loading unit (130) installed at an upper front of the main body (101) for loading a print medium printed by the print unit (120); And a print medium reverse transfer unit 200 which transfers the print medium printed by the print unit 120 to the stacking unit 130.

The printing unit 120 may employ a printing method according to the electrophotographic method.

In more detail, as shown in FIG. 1, the printing unit 120 includes a plurality of developing cartridges 121; A plurality of exposure units 124 respectively corresponding to the plurality of developing cartridges 121; A plurality of transfer rollers 123 for transferring an image formed on a consultation body 122 to be described later accommodated in the plurality of developing cartridges 121 to a print medium; Transfer belt 125; A plurality of driving rollers 126 for driving the conveying belt 125; And a fixing unit 127.

The plurality of developing cartridges 121 stores a developer (toner) of yellow (Y), magenta (M), cyan (C) and black (K) colors, respectively, and accommodates the counseling member 122 therein. do.

The plurality of exposure units 124 expose the consultation members 122 of the developing cartridge 121, respectively. Accordingly, the developer stored in the developing cartridge 121 is applied to each exposure area of the consultation body 122 to form a visible image on the surface thereof.

The transfer belt 125 transfers the print medium such that the print medium supplied from the paper feeding unit 110 to be described later passes through the consultation body 122 and the transfer roller 233.

Accordingly, the visible image formed on the surface of the consultation member 122 is transferred to the print medium on the transfer belt 125 by the transfer roller 233. As the print medium sequentially passes through the plurality of counseling members 122 and the plurality of transfer rollers 233, visible images of yellow, magenta, cyan and black colors are transferred to the print medium in a superimposed manner. As a result, a color visible image is formed on the print medium.

The color visible image is fixed to the print medium while passing through the fixing unit 127. The fixing unit 127 includes a heat roller 127a for applying heat to the color visible image; And a press roller 127b for pressing the print medium in the direction of the heat roller 127a.

The printing of the print medium is completed by passing through the fixing unit 127.

The printing unit 120 described above is only one example and may be variously changed. In some cases, at least one of an inkjet method for ejecting ink through a nozzle or a thermal transfer method using a thermal printing head (TPH) may be employed instead of or in conjunction with the electrophotographic method.

The image forming apparatus 100 further includes a paper feeding unit 110 for supplying a print medium to be printed to the printing unit 120.

The paper feeding unit 110 may be attached to or detached from the main body 101 to enable recharging when the print medium is exhausted.

The paper feeding unit 110 includes a knock-up plate 111 for loading the print medium to be printed; A pickup roller 115 which picks up the print medium on the knock-up plate 111 to the print unit 120; It includes an elastic member 113 for elastically biasing the knock-up plate 111 toward the pickup roller 115.

On the other hand, the print medium transfer unit 200, as shown in Figure 1 and 2, the frame 210; Guide plate 220; And a plate driver 230.

The frame 210 forms a first transport path S1 through which the print medium passing through the printing unit 120 is transported, and a second transport path S2 crossing the first transport path S1.

Here, the first transfer path (S1) is connected to the printing unit 120 and the guide plate 220, the second transfer path (S2) is the guide plate 220 and the loading unit 130 Connect

In more detail, the first transfer path S1 is a path through which the print medium from the printing unit 120 to the guide plate 220 is transferred, and the second transfer path S2 is the guide plate. The print medium is transferred from the 220 to the loading unit 130.

Meanwhile, as illustrated in FIGS. 3A and 3C, the guide plate 220 includes a first position c and a guide plate for loading the print medium P transferred along the first transfer path S1. The printing medium P loaded on the 220 may be rotated between the second positions d for redirecting the printing medium P in the direction of the second transfer path.

The guide plate 220 is rotatable around a hinge shaft 221 installed on the downstream side of the first transfer path S1.

In more detail, one end of the guide plate 220 is connected to the hinge shaft 221 and the other end of the guide plate 220 is supported by an actuator 231 which will be described later.

The plate driver 230 includes an actuator 231 for rotating the guide plate 220 as shown in FIGS. 1 and 2; A drive source 235 for driving the actuator 231; And an electronic clutch 233 for selectively transmitting the driving force of the driving source 235 to the actuator 231.

As shown in the figure, the actuator 231 may be provided as a cam that rotates in one direction about the cam shaft 231a. Of course, in addition to the cam, various driving means may be employed as long as the plate 220 can be elevated.

In addition, the print medium reverse transfer unit 200 and the sensor unit 240 disposed on the first transfer path (S1); The control unit 280 further controls the plate driver 230 based on the detection result of the sensor 240.

Hereinafter, referring to FIGS. 3A to 4, a process of transferring the printed media to the stacking unit 130 through the first transfer path S1 and the second transfer path S2 will be described. do.

On the other hand, the sensor unit 240, as shown in Figure 3a, a lever 241 that can be in contact with the print medium transported along the first transfer path (S1); The light sensor includes a photosensor 243 is transmitted or blocked to the light receiving unit according to the change in the attitude of the lever 241.

The lever 241 has a blocking position (FIG. 3B) for blocking the light of the light emitting part about the hinge axis 242, and a release position (FIG. 3A) spaced apart from the blocking position (FIG. 3B). ) Can be rotated.

Here, the sensor unit 240 may further include an elastic member (not shown) for elastically biasing the lever 241 so that the lever 241 maintains the blocking position.

In more detail, when the print medium is in contact with the lever 241, the lever 241 is rotated to the release position shown in Figure 3a. Accordingly, the light of the light emitting unit is transmitted to the light receiving unit so that the photosensor 243 outputs an "ON" signal as a detection signal. On the contrary, when the print medium does not contact the lever 241, the lever 241 is positioned at the blocking position shown in Figs. 1, 3B and 3C by the elastic member (not shown). Accordingly, since the light of the light emitting unit is not transmitted to the light receiving unit, the photosensor 243 outputs an "OFF" signal as a detection signal.

As shown in FIG. 4, when the detection signal of the photosensor 243 is switched from " OFF " to " ON " at time t1, the front end of the print medium P as shown in FIG. 3A at time t1. (a) is in contact with the lever 241 means that the lever 241 is rotated.

When the detection signal of the photosensor 243 is switched back from the "ON" signal to the "OFF" signal as in time t2 after time t1, as shown in FIG. 3B at the time t2, as shown in FIG. It means that the rear end b has just passed through the lever 241.

The controller 280 may control the electronic clutch 233 based on the detection result of the sensor unit 240.

In more detail, the control unit 280 is the electronic clutch until the rear end (b) of the printing medium (P) transferred along the first transfer path (S1) is supported by the guide plate 220. Turn off (233). As a result, since the driving force of the driving source 235 is not transmitted to the actuator 231, the guide plate 220 is positioned at the first position (c of FIG. 3A).

Here, the controller 280 may determine the time point t3 at which the rear end b of the printing medium P is supported by the guide plate 220 based on the detection signal of the porter sensor 243. .

In more detail, the control unit 280 indicates the time when a predetermined time has elapsed at a time t2 when the detection signal of the photosensor 243 is switched from the "ON" signal to the "OFF" signal. The rear end b) may be determined as a time point t3 supported by the guide plate 220.

In this case, the predetermined time is taken for the rear end b of the printing medium P to be conveyed along the first transfer path S1 to pass the distance between the lever 141 and the guide plate 220. It can be calculated in consideration of time.

The controller 280 controls the electronic clutch 233 for a predetermined time (Δt1) after the point in time at which the rear end b of the print medium P is supported by the guide plate 220. ON by).

The driving force of the driving source 235 is transmitted to the actuator 231 during the predetermined time Δt1 so that the guide plate 220 rotates to the second position (d in FIG. 3C).

Accordingly, the printing medium P supported by the guide plate 220 is also turned in the direction of the second transfer path S2 toward the loading unit 130.

As described above, since the conveying direction of the print medium can be simply turned by the ON / OFF operation of the electronic clutch, the print medium can be smoothly discharged to the outside during high speed printing.

In addition, since the rotation radius of the first plate (c) and the second position (d) of the guide plate 220 is small, it is possible to change the conveying direction of the print medium at high speed.

Meanwhile, as illustrated in FIGS. 1 and 3A to 3C, the print medium reverse transfer unit 200 receives the print medium P supported by the guide plate 220 in the second transfer path S2. It may further include a first drive roller 253 for conveying along.

In addition, the print medium reverse transfer unit 200 may further include a contact portion 255 contacting the first driving roller 253 or spaced apart from the first driving roller 253.

The contact part 255 may contact the first driving roller 253 with the print medium P therebetween so as to transfer the print medium P in the direction of the second transfer path S2. As long as it can be provided in various forms. 3A illustrates an idle roller 255 as an example of the contact portion 255. However, it is not necessarily limited to the idle roller 255 and may be replaced with any one of a sliding part (not shown) and an elastic pad (not shown). The elastic pad (not shown) may be made of a sponge or a soft plastic material.

In addition, the contact part 255 may be installed on the guide plate 220. As an example, as shown in FIGS. 1 and 3A, the idle roller 255 may be rotatably supported by the guide plate 220.

In some cases, the contact portion 255 may perform the function of the contact portion 255 without the idle roller 255, the guide plate 220 itself.

On the other hand, as shown in Figure 3a, when the guide plate 220 is located in the first position (c), the contact portion 255 is spaced apart from the first drive roller 253. Accordingly, the print medium P traveling along the first transfer path S1 may pass through the separation space between the first driving roller 253 and the contact part 255.

Here, the print medium reverse transfer unit 200, as shown in Figure 3a, to prevent the print medium (P) supported by the guide plate 220 is separated from the guide plate 220 It may further include a departure prevention unit 270 for.

The release preventing part 270 includes a pressure lever 273 facing the guide plate 220 with the print medium P transferred along the first transfer path S1 therebetween. The release preventing part 270 may further include an elastic member (not shown) for elastically biasing the pressure lever 273 toward the guide plate 220.

The print medium P transferred along the first transfer path S1 passes between the pressure lever 273 and the guide plate 220 as shown in FIG. 3B. The print medium P interposed between the pressure lever 273 and the guide plate 220 may have the print medium P even when the guide plate 220 is inclined, as shown in FIG. 3C. Since the pressing lever 273 is being pressed, it is not separated from the guide plate 220.

Here, the elastic force by which the elastic member (not shown) elastically biases the pressure lever 273 toward the guide plate 220 does not seriously impede the transfer of the printing medium P. It may be appropriately determined in a range capable of preventing the departure of P).

In addition, the print medium reverse transfer unit 200 may further include a second driving roller 263, as shown in Figure 1 and 3a to 3c.

The second driving roller 263 rotates in one direction G to transfer the print medium P along the first transfer path S1 and to be supported by the guide plate 220. ) Is transferred along the second transfer path S2.

In more detail, as shown in FIG. 1, the first transfer path S1 and the second transfer path S2 may be disposed at intersections with each other.

Here, the first driving roller 253 and the second driving roller 263 may be driven by the drive source 235. Of course, in some cases it may be driven by a drive source separate from the drive source 235.

The controller 280 may drive the first driving roller 253 and the second driving roller 263 by controlling the driving source 235 based on the detection result of the sensor unit 240.

In more detail, when it is determined that the front end a of the printing medium P passes through the sensor unit 240 as a result of the detection of the sensor unit 240, the control unit 280 235) is turned on.

Here, between the driving source 235, the first driving roller 253 and the second driving roller 263, the power of the driving source 235, respectively, the first driving roller 253 and the second driving roller. A gear (not shown) for transmitting to 263 is provided. Accordingly, the first driving roller 253 rotates in one direction F to transfer the print medium P to the second transfer path S2, and the second driving roller 263 also rotates. Rotate in one direction (G).

Accordingly, the first driving roller 253 and the second driving roller 263 can be rotated in one direction (F, G) described above without a separate clutch, thereby reducing the product cost.

In addition, since the direction of rotation of the drive shaft of the driving source 235 does not need to be changed during the transfer of the print medium P to the first transfer path S1 and the second transfer path S2, the print medium at high speed. (P) can be discharged.

On the other hand, as shown in Figure 3a, the print medium (P) conveyed along the first transfer path (S1), even if the first drive roller 253 is rotated in the one direction (F), Since the distance between the guide plate 220 and the first driving roller 253 is wide, it is not disturbed by the rotation of the first driving roller 253.

In addition, when the separation preventing part 270 is installed, interference may not occur further by the one direction rotation of the first driving roller 253. Accordingly, the print medium P may be supported by the guide plate 220 to the rear end b of the print medium P, as shown in FIG. 3B.

Subsequently, as described above, after the point b of the rear end b of the printing medium P is supported by the guide plate 220, the electronic clutch 233 starts the predetermined time from? ON by t1).

Accordingly, the guide plate 220 is rotated to the second position (d), as shown in Figure 3c, the contact portion 255 installed on the guide plate 220 also the print medium (P) The first driving roller 253 is in contact with each other. Since the first driving roller 253 is rotationally driven in the one direction (F), the print medium (P) is conveyed in the reverse direction along the second transfer path (S2).

Here, the print medium reverse transfer unit 130 may further include a discharge roller 267 disposed downstream of the second transfer path S2.

The print medium P which is conveyed backward along the second transfer path S2 is driven by the driven roller 265 driven by the second driving roller 263 and the second driving roller 263. It is conveyed to the discharge roller 267.

The discharge roller 267 discharges the transferred print medium P to the loading unit 130.

On the other hand, the control unit 280 is the front end (a) (rear end for the reverse direction) of the print medium (P) as the print medium (P) is transferred along the second transfer path (S2) When it is determined that the guide plate 220 has exited, for example, the electronic clutch 233 may be turned on for a predetermined time Δt2 from the time t5 to the time t6. Accordingly, the guide plate 220 at the second position (d of FIG. 3c) may be restored to the original first position (c of FIG. 3c).

By quickly restoring the guide plate 220 to the first position (c in FIG. 3C), the next printing medium may be returned even if the printing medium P does not completely exit the second transfer path S2. The guide plate 220 may be transferred.

Here, the time t5 may be estimated in consideration of the rotational speeds of the first driving roller 253 and the second driving roller 263 from the actual sensing time t2.

In some cases, the sensor unit capable of detecting a print medium is separately disposed in a section E between the second driving roller 263 and the discharge roller 267 in the second transfer path S2. The electronic clutch 233 may be controlled based on the detection result of the sensor unit. Here, the sensor unit may employ the same method as the sensor unit 240 described above.

When the control unit 280 prints the plurality of print media P, after the final print media P is discharged to the outside through the discharge roller 267, for example, at the time t7, the driving source 235 ) Can be turned OFF.

The image forming apparatus 100 may further include a cover 103 rotatable around the hinge shaft 102 on the main body 101.

The image forming apparatus 100 may further include a scanner 140 disposed under the cover 103 to scan an image of an original.

The image data scanned by the scanner 140 may be printed by the printing unit 120.

In the above, the controller 280 has been described as being included in the print medium reverse transfer unit 200, but may not be included in the print medium reverse transfer unit 200 as necessary.

In more detail, a control signal for controlling the driving source 235 and the electronic clutch 233 is external to the print medium reverse transfer unit 200, that is, a control unit provided in the image forming apparatus 100 (not shown). May be received from).

For example, the print medium reverse transfer unit 200 may include an input port for receiving the control signal and may be detachably attached to the main body 101.

Meanwhile, as shown in FIG. 2, the image forming apparatus 100 may further include an operation panel 150 installed at an upper front side of the main body 101.

The operation panel 150 includes an input window (not shown) and an input key (not shown).

The user receives information about the image forming apparatus 100 through the operation panel 150 or inputs a command such as a copy command or a print command.

As shown in FIG. 5, the image forming apparatus 100a according to the modified embodiment of the present invention includes a main body 101a having a through hole 104 through which a print medium P can pass, and the through hole 104. It may include a through hole shielding cover 105 surrounding the periphery.

Here, the through hole shielding cover 105 may be omitted in some cases due to the size of the image forming apparatus 101a.

The front end of the printing medium P, which is transferred along the first transfer path (S1 of FIG. 1) by the second driving roller 263, may pass through the through hole 104 and exit out of the main body 101a. have. By placing a part of the transfer path of the print medium outside the main body 101a, the size of the image forming apparatus 100a can be reduced and reduced in weight compared with accommodating the entire transfer path therein.

Here, even if a portion of the printing medium P is pulled out of the main body 101a through the through hole 104, the printing medium P is guided by the separation prevention part 270 by the guide plate 220. Departure can be prevented from.

In addition, the through hole shielding cover 105 may be detachably installed on the main body 101a. For example, the main body 101a may be rotatably installed around a hinge axis (not shown) provided or may be detachably installed to the main body 101a by a locking method or a fitting method.

On the other hand, the above embodiments are merely exemplary, and those skilled in the art may have various modifications and other equivalent embodiments therefrom.

Accordingly, the true scope of protection of the present invention should be determined by the technical idea of the invention described in the following claims.

*

1 is a schematic cross-sectional view of an image forming apparatus according to an embodiment of the present invention;

2 is a block diagram of the image forming apparatus of FIG. 1;

3A to 3B are schematic cross-sectional views sequentially illustrating a printing medium conveying process of the printing medium reverse conveying unit of the image forming apparatus of FIG. 1;

4 is a timing diagram of a photosensor, an electronic clutch and a driving source of the image forming apparatus of FIG.

5 is a schematic cross-sectional view of an image forming apparatus according to a modified embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

100, 100a: image forming apparatus 120: printing unit

130: loading unit 140: scanner

200: print medium reverse feed unit 210: frame

220: guide plate 230: plate driving unit

231: actuator 233: electronic clutch

235: drive source 240: sensor unit

241: lever 243: photosensor

253: first drive roller 255: contact portion

263: second drive roller 265: driven roller

267: discharge roller

Claims (12)

In the print medium reverse transfer unit of the image forming apparatus, A frame forming a first transfer path through which a print medium is transferred and a second transfer path crossing the first transfer path; A guide plate rotatable between a first position for supporting the print medium conveyed along the first conveyance path and a second position for redirecting the loaded print medium in the direction of the second conveyance path; And a plate driver including an actuator for rotating the guide plate, a drive source for driving the actuator, and an electromagnetic clutch for selectively transmitting a driving force of the drive source to the actuator. The method of claim 1, A sensor unit disposed on the first transfer path; And a control unit for controlling the plate driving unit based on the detection result of the sensor unit. The method of claim 1, A first driving roller for transferring the print medium along the second transfer path; And contacting the first driving roller with the print medium therebetween when the guide plate is in the second position and spaced apart from the first driving roller when the guide plate is in the first position. Print media reverse transfer unit, characterized in that. The method of claim 3, And the contact portion includes at least one of an idle roller, a sliding portion, and an elastic pad. The method of claim 3, And the contact portion is installed on the guide plate. The method of claim 3, And a second driving roller which rotates in one direction and transfers the print medium to the first transfer path and transfers the print medium supported by the guide plate along the second transfer path. Reverse feed unit. The method of claim 6, And the first driving roller and the second driving roller are driven by the driving source. The method of claim 1, And a separation preventing part for preventing the print medium supported by the guide plate from being separated from the guide plate. The method of claim 1, And said actuator comprises a cam. An image forming apparatus having a main body, A printing unit accommodated in the main body and printing a print medium; A loading unit installed at an upper side of the main body, for storing a printing medium printed by the printing unit; 10. An image forming apparatus according to any one of claims 1 to 9, wherein the print medium printed by the printing unit is conveyed back to the stacking unit. The method of claim 10, The first transfer path connects the printing unit and the guide plate, And the second transfer path connects the guide plate and the loading unit. The method of claim 10, And the print medium reverse transfer unit is detachable from the main body.

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