CN1760767B - Paper arrangement device and electrophotographic image forming apparatus having the same - Google Patents

Abstract

The invention discloses a paper arrangement device and an electrophotographic imaging device with the paper arrangement device. The paper arranging device includes: a drive roller and a guide roller arranged adjacent to each other to form a nip; a first sensor to detect the position of the moving paper; and a control lever having a first end and another end, the first end extending to The perimeter of the nip is to block the tip of the paper moving toward the nip, the other end extends to the perimeter of the sensor, and the lever is relative to a predetermined distance between the first end and the second end of the lever. The pivot is rotatable. When the first end of the control rod is pushed by the tip of the moving paper and reaches the first position, the first sensor determines that the tip of the paper is entering the nip and generates a first sensing signal. When the first end of the lever is pushed by the tip of the moving paper and reaches the second position where the paper advances farther than the first position, the first sensor determines that the tip of the paper has passed the nip and generates a second sensing signal.

Description

Paper arrangement device and electrophotographic image forming apparatus having the same

technical field

The present invention relates to a paper arranging device, and more particularly, to an electrophotographic image forming apparatus provided with the paper arranging device.

Background technique

In general, an electrophotographic image forming apparatus prints a desired image by developing a latent image formed on the periphery of a photosensitive medium by light scanning into a visible image, transferring the visible image to paper, and fusing the visible image with the paper, wherein by providing The toner is applied to the latent image to develop the latent image. As the paper is conveyed along a predetermined path, the visible image is transferred to and fuses with the paper. The paper placement device arranges the paper for movement towards the photosensitive medium to transfer the visible image to the desired portion of the paper. The paper arranging device is installed in front of the photosensitive medium in a predetermined path of paper conveyance.

1 and 2 are diagrams showing the operation of a conventional paper arrangement device 10 installed in a conventional electrophotographic image forming apparatus. Referring to FIGS. 1 and 2 , the paper arrangement device 10 includes a driving roller 12 , a guide roller 14 , a photoelectric sensor 16 and a control rod 18 . The drive roller 12 and the guide roller 14 face each other so that a nip N is formed. The tip Pa of the moving paper P pushes and rotates the lever 18 . Drive roller 12 is rotated by power generated by a motor (not shown), and through an electronic clutch (not shown), drive roller 12 is selectively connected to or disconnected from the motor.

Until the tip Pa of the upwardly moving paper P (see arrows in FIGS. 1 and 2 ) reaches the lever 18, the electronic clutch connects the drive roller 12 to the motor, thereby preventing the drive roller 12 and the guide roller 14 from rotating. When the tip Pa of the paper P pushes the first end 18a of the lever 18 upward, the lever 18 rotates so that the second end 18b of the lever 18 turns downward. Then, referring to FIG. 2, the second end 18b is separated from the photoelectric sensor 16, and the photoelectric sensor 16 detects the paper P. As shown in FIG. Next, the tip Pa of the paper P is crimped by the nip N to arrange the paper P. As shown in FIG. A predetermined time after the photoelectric sensor 16 detects the paper P, the electronic clutch connects the driving roller 12 to the motor, and the driving roller 12 and the guide roller 14 rotate to convey the paper P. An optical scanning device (not shown) and a photosensitive medium (not shown) are sequentially operated to transfer an image onto a desired portion of the paper P after a predetermined time after the clutch action.

The conventional paper arranging device 10 sets a time, ie, an exposure time, when the light scanning device and the photosensitive medium start to operate according to the time when the clutch starts to act. Thus, the delay in clutch actuation increases the error between the actual position of the image on the paper P and the desired position.

3 to 5 are diagrams showing the operation of another conventional paper arranging device 50 installed in a conventional electrophotographic image forming apparatus. Referring to FIGS. 3 to 5 , the paper arrangement device 50 includes a driving roller 52 , a guide roller 54 , lower and upper levers 58 and 64 , and lower and upper photoelectric sensors 56 and 62 . The drive roller 52 and the guide roller 54 face each other to form a nip N, and are installed between the lower and upper levers 58 and 64 and between the lower and upper photoelectric sensors 56 and 62 . Drive roller 52 is rotated by power generated by a motor (not shown), and drive roller 12 is selectively connected to or disconnected from the motor by an electronic clutch (not shown).

Until the tip Pa of the upwardly moving paper P (see arrows in FIGS. 3-5 ) reaches the lower lever 58, the electronic clutch connects the drive roller 52 to the motor, preventing the drive roller 52 and guide roller 54 from rotating. When the tip Pa of the paper P pushes the first end 58a of the lower lever 58 upward, the lower lever 58 rotates so that the second end 58b of the lower lever 58 turns downward. Then, referring to FIG. 4, the second end 58b of the lower lever 58 is separated from the lower photoelectric sensor 56, and the lower photoelectric sensor 56 detects the paper P. Referring to FIG. Next, the tip Pa of the paper P is stopped and curled by the nip N, so that the paper P is arranged. A predetermined time after the lower photoelectric sensor 56 detects the paper P, the electronic clutch connects the driving roller 52 with the motor, and the driving roller 52 and the guide roller 54 rotate to convey the paper P.

When the tip Pa of the paper P passes through the nip N and pushes the first end 64a of the upper lever 64 upward, the upper lever 64 rotates so that the second end 64b of the upper lever 64 turns downward. Then, referring to FIG. 5 , the second end 64 b of the upper lever 64 is separated from the upper photoelectric sensor 62 , and the upper photoelectric sensor 62 detects that the tip Pa of the traditional paper P passes through the paper arrangement device 50 . A light scanning device (not shown) and a photosensitive medium (not shown) start to operate a predetermined time after the upper photosensor 62 detects the paper P, and transfer an image onto a desired portion of the paper P.

The conventional paper arranging device 50 of FIGS. 3 to 5 sets the time, ie, the exposure time, when the light scanning device (not shown) and the photosensitive medium (not shown) start operating according to the time when the upper photosensor 62 detects the paper P. Thus, unlike the paper arrangement device 10 of Figures 1-2, irregular delays in clutch actuation do not add significantly to the error between the actual and desired positions of the images on the paper P. However, compared with the conventional paper arranging device 10 of FIGS. 1-2, the conventional paper arranging device 50 of FIGS. 3 to 5 requires an additional photoelectric sensor and an additional control lever, thereby increasing manufacturing costs.

Contents of the invention

The present invention provides a paper arranging device with a sensor and a lever, and an electrophotographic image forming apparatus having the paper arranging device capable of minimizing an error between an actual position and an expected position of an image on a paper.

Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The foregoing and/or other aspects and advantages of the present invention can be achieved by providing a paper arranging device for an electrophotographic image forming apparatus, the paper arranging device comprising: a drive roller and a guide roller arranged adjacent to each other to form a nip roller; a first sensor that senses the position of the moving paper; and a lever having a first end and a second end, the first end extending to the perimeter of the nip to block movement toward the The tip of the paper moved by the nip, the second end extends to the perimeter of the sensor, and the lever is movable relative to a predetermined pivot between the first end and the second end of the lever. rotate. When the first end of the control rod is pushed by the tip of the moving paper and reaches a first position, the first sensor determines that the tip of the paper is entering the nip and generates a first transmission. sense signal. When the first end of the lever is pushed by the tip of the moving paper and reaches a second position where the paper advances farther than the first position, the first sensor determines the paper The tip has passed the nip and a second sensor signal is generated.

A time when the driving roller rotates may be determined based on a first sensing signal output from the first sensor.

A time at which the photosensitive medium of the electrophotographic image forming apparatus on which a latent image is formed is exposed may be determined based on the second sensing signal output from the first sensor.

The paper arranging device may further include a limiter for adjusting a rotation angle of the lever.

The control rod is resiliently biasable such that the first end of the control rod is returnable to its initial position in which the first end of the control rod blocks the movement of the paper towards the nip tip.

The first sensor may be a photoelectric sensor.

The paper arranging device may further include a second sensor spaced apart from the first sensor and detecting a position of the moving paper. When the first end of the lever is pushed by the tip of the paper and reaches a third position deviated from the paper path, the second sensor can determine that the paper is passing through the nip and can generate a first Three sensing signals. When the first end of the control rod returns from the third position to the initial position, the second sensor can determine that the end of the paper has passed the nip and can generate a fourth sensing signal.

The second sensor may be a photoelectric sensor.

At least one of the driving roller and the guide roller may include a cutout portion, and the lever is disposed in the cutout portion.

The foregoing and/or other aspects and advantages of the present invention will be achieved by providing an electrophotographic imaging apparatus comprising: an optical scanning device for scanning light corresponding to an image signal; a photosensitive medium, when said photosensitive a latent image formed on the photosensitive medium when the medium is exposed to the light; a paper arrangement device; and a controller, the controller according to a first sensor signal output from a first sensor of the paper arrangement device and the second sensing signal to control the rotation time of the driving roller of the paper arrangement device and the exposure time of the photosensitive medium. The paper arranging device includes: a drive roller and a guide roller located in front of the photosensitive medium along a paper path, the drive roller and the guide roller are arranged adjacent to each other to form a nip; a device for detecting the position of the moving paper a first sensor; and a lever having a first end and a second end, the first end extending to the perimeter of the nip to block the tip of the paper moving toward the nip, the The second end extends to the perimeter of the first sensor, and the lever is mounted rotatably relative to a predetermined pivot between the first and second ends of the lever. When the first end of the control rod is pushed by the tip of the paper and reaches a first position, the first sensor determines that the tip of the paper is entering the nip and generates a first sensing signal . When the first end of the lever is pushed by the tip of the paper and reaches a second position where the paper advances farther than the first position, the first sensor determines that the tip of the paper has passing through the nip and generating a second sensing signal.

The paper arranging device may further include a clutch for selectively transmitting power generated by a driving source to the driving roller, and based on the first sensing signal output from the first sensor, the controller may pass The clutch is operated to control when the drive roller rotates.

The controller may control the exposure time of the photosensitive medium by operating the light scanning device and the photosensitive medium according to the second sensing signal output from the first sensor.

The paper arranging device may further include a limiter for adjusting a rotation angle of the lever.

The lever is resiliently biasable such that the first end of the lever returns to its initial position in which the first end of the lever blocks movement of the paper towards the nip. cutting edge.

The first sensor may be a photoelectric sensor.

The paper arranging device may further include a second sensor spaced apart from the first sensor and detecting a position of the moving paper. When the first end of the lever is pushed by the tip of the paper and reaches a third position deviated from the paper path, the second sensor can determine that the paper is passing through the nip and can generate a third sensing signal. When the first end of the lever returns to the initial position from the third position, the second sensor can determine that the end of the paper has passed the nip and can generate a fourth sensor Signal.

The second sensor may be a photoelectric sensor.

Description of drawings

These and/or other aspects and advantages of the present invention will become apparent and easier to understand from the following description of embodiments in conjunction with the accompanying drawings, in which:

1 and 2 are diagrams illustrating the operation of a conventional paper arrangement device installed in a conventional electrophotographic image forming apparatus;

3 to 5 are diagrams showing operations of another conventional paper arrangement device installed in a conventional electrophotographic image forming apparatus;

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

7 is a perspective view showing a paper arranging device according to an embodiment of the present invention;

8 to 11 are diagrams illustrating operations of the paper arranging device of FIG. 7;

12 is a perspective view showing a paper arranging device according to another embodiment of the present invention;

13 to 17 are diagrams illustrating operations of the paper arranging device of FIG. 12 .

Detailed ways

Embodiments of the present invention will be described in detail below, together with examples shown in the drawings, wherein like numerals refer to like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.

6 shows an electrophotographic image forming apparatus 100 according to an embodiment of the present invention. The electrophotographic image forming apparatus 100 includes a housing 101, a developing unit 110 that is easily mounted to and removed from the housing 101, a fixing unit 130, a transfer roller 125, and Light Scanning Unit (LSU) 127 . As shown in FIG. 6 , the paper P is conveyed along an inverted C-shaped conveyance path in the electrophotographic image forming apparatus 100 .

The developing unit 110 includes a housing 111 storing a developing solution (ie, toner), a photosensitive medium 115 on which a latent image is formed by optical scanning, a charging roller 113 charging the photosensitive medium 115, and collecting waste developing solution from A waste developer cleaner 114 removed from the photosensitive medium 115, a developing roller 117 for developing a latent image formed on the periphery of the photosensitive medium 115 into a visible image by supplying a developer to the latent image on the periphery of the photosensitive medium 115, controlling sticking A doctor blade 118 attached to the surface of the developing roller 117 to the thickness of the developer, and a supply roller 119 that supplies the developing roller 117 to the developing roller 117 . The stirrer 121 is installed in the box 111 to stir the developer so that the developer does not solidify. The developing unit 110 as shown in FIG. 6 is of a cartridge type. Therefore, when the developer stored in the developing unit 110 is consumed, the developing unit 110 can be replaced with a new developing unit.

The transfer roller 125 is installed to face the photosensitive medium 115 . The visible image developed on the periphery of the photosensitive medium 115 is transferred to the paper P passing between the transfer roller 125 and the photosensitive medium 115 by a transfer bias or contact pressure between the transfer roller 125 and the photosensitive medium 115 .

The fixing unit 130 includes a heating roller 131 and a platen roller 133 installed to face the heating roller 131 . When the paper P on which the visible image is transferred passes between the heat roller 131 and the platen roller 133, the visible image is fused with the paper P by heat pressing using heat and pressure.

The electrophotographic image forming apparatus 100 also includes a pickup roller 145 , a paper arrangement device 150 , and a lead-out roller 135 . The pickup roller 145 picks up a sheet of paper P stacked in the paper feeding cassette 140 installed at the bottom of the housing 101 . The paper arranging device 150 provides conveying force to the picked paper P and arranges the picked paper P to be conveyed toward the photosensitive medium 115 so that a visible image can be transferred on a predetermined portion of the paper P. The paper arrangement device 150 includes a driving roller 152 and a guide roller 154 . The take-out roller 135 helps push the image-printed paper P toward the paper output tray 102 outside the casing 101 .

The operation of the electrophotographic image forming apparatus 100 will now be described. The photosensitive medium 115 is charged to a predetermined potential by the charging roller 113 and exposed to light L scanned by the light scanning device 127 to form a latent image on the periphery of the photosensitive medium 115, the latent image corresponding to an image to be printed. The toner contained in the cartridge 111 of the developing unit 110 is supplied to the photosensitive medium 115 on which a latent image is formed by a supply roller 119 and a developing roller 117 . Then, the latent image is developed into a visible image. The paper P stacked in the paper feeding cassette 140 is picked up by the pickup roller 145 , conveyed and arranged by the paper arrangement device 150 , and passes between the photosensitive medium 115 and the transfer roller 125 . Then, the visible image developed on the periphery of the photosensitive medium 115 is transferred to the side of the paper P facing the photosensitive medium 115 . The fixing unit 130 applies heat and pressure to the paper P to fuse the visible image and the paper P when the transferred visible image passes through the fixing unit 130 . Subsequently, the paper P is conveyed to the paper output cassette 102 by the lead-out roller 135 .

7 to 11 illustrate a paper arrangement device 150A according to an embodiment of the present invention. The paper arranging device 150A includes a driving roller 152 and a guide roller 154 installed closely to face each other so as to form a nip N therebetween, a photoelectric sensor 160 which senses the position of the conveyed paper P, and a tip of the paper P which is moved. Pa pushes and rotates the lever 165 . The driving roller 152 is rotated by power generated by a motor (not shown) installed in the casing 101 (see FIG. 6 ), and is connected to the motor through an electronic clutch 192 . The power generated by the motor is selectively transmitted to the drive roller 152 through the electronic clutch 192 . Electronic clutch 192 is electrically connected to controller 190 and operates in response to control signals generated by controller 190 . The motor, the electronic clutch 192 and the controller 190 are obvious to those skilled in the art, so a detailed description thereof is omitted. The transmission roller 152 may have a cutout portion, and the control rod 165 may be placed in the cutout portion.

The first end 166 of the lever 165 extends to the nip N at the initial position, so that when the tip Pa of the paper P approaches the nip N in the forward direction of movement by the pick-up roller 145 (see FIG. 6 ), the first The end 166 is in contact with the tip Pa of the paper P, and the second end 167 of the lever 165 extends to the photosensor 160 so that the second end 167 is positioned above the slit 161 of the photosensor 160 in the initial position. The lever 165 is mounted rotatably about a predetermined pivot 168 between the first and second ends 166 and 167 . The spring 177 elastically biases the lever 165 in the counterclockwise direction so that the lever 165 returns even when the tip Pa of the moving paper P pushes the lever 165 to rotate the lever 165 clockwise relative to the pivot 168. to the initial position. One end of the spring 177 is connected to a predetermined frame (not shown) in the housing 101 (see FIG. 6 ), and the other end thereof is connected to the lever 165 . A limiter 175 is also installed in the casing 101 for controlling the rotation angle of the control lever 165 which rotates counterclockwise under the action of a spring 177 after the paper P passes through the nip N. When the control rod 165 rotates counterclockwise under the action of the spring 177, the limiter 175 stops the rotation of the control rod 165 at the initial position. As shown in FIGS. 8-11, the lever 165 rotates clockwise under the action of the paper P, and counterclockwise under the action of the spring 177, but the present invention is not limited thereto. Alternatively, the lever 165 may be rotated counterclockwise by the paper P and clockwise by the spring 177 .

The slit 161 is formed in the lengthwise direction of the photoelectric sensor 160 such that the second end 167 of the lever 165 can pass through the photoelectric sensor 160 . A light emitting unit (not shown) emitting laser light and a light receiving unit (not shown) receiving laser light are installed on opposite inner walls of the slit 161 . The configuration of the slit 161 is obvious to those skilled in the art, so a detailed description thereof will be omitted. The photoelectric sensor 160 is electrically connected to the controller 190 , detects the position of the paper P, generates first and second sensing signals indicating the position of the paper P, and transmits the first and second sensing signals to the controller 190 .

The operation of the paper arrangement device 150A of FIGS. 7-11 will now be described. 8, when the lever 165 is in the initial position, the first and second ends 166 and 167 of the lever 165 are positioned directly below the nip N and above the photoelectric sensor 160, respectively. Until the paper P picked up by the pickup roller 145 (see FIG. 6 ) moves upward and the tip Pa of the paper P reaches the first end 166 of the lever 165, the electronic clutch 192 drives the roller 152 in response to a control signal generated by the controller 190. Connect with the motor. In this case, the drive roller 152 and the guide roller 154 installed adjacent to the drive roller 152 do not rotate.

Referring to FIG. 9 , when the tip Pa of the paper P pushes the first end 166 of the lever 165 upward to the first position, the lever 165 rotates clockwise to rotate the second end 167 of the lever 165 downward. Therefore, the second end 167 of the lever 165 enters the slit 161 of the photosensor 160, and the laser light emitted by the light emitting unit of the photosensor 160 is blocked by the second end 167 of the lever 165, thereby preventing light from entering the light receiving unit. In this case, the photoelectric sensor 160 determines that the tip Pa of the paper P is approaching the nip N, and generates a first sensing signal.

Then, the tip Pa of the paper P is stopped and curled by the nip N, so that the paper P is arranged. The first sensing signal output from the photo sensor 160 is transmitted to the controller 190 . At a first interval after the controller 190 receives the first sensing signal, the controller 190 generates a control signal and transmits the control signal to the electronic clutch 192 to activate the electronic clutch 192 . When the electronic clutch 192 is activated, the driving roller 152 is connected to the motor, so that the driving roller 152 and the guide roller 154 installed adjacent to the driving roller 152 rotate to move the paper P.

Referring to FIG. 10 , while being pushed by the tip Pa of the paper P passing through the nip N, the first end 166 of the lever 165 continuously rotates in the clockwise direction. Referring to FIG. 11 , when the first end 166 reaches the second position where the paper P advances farther than the first position, the second end 167 of the lever 165 does not block the light emitted by the light emitting unit of the photosensor 160 . Thus, the light receiving unit receives the laser light, and the photosensor 160 determines that the tip Pa of the paper P has passed through the nip N, and generates a second sensing signal.

The second sensing signal output from the photo sensor 160 is transmitted to the controller 190 . At a second interval after receiving the second sensing signal, the controller 190 generates and transmits a control signal so that the light scanning device 127 and the photosensitive medium 115 (see FIG. 6 ) operate to expose the photosensitive medium 115 to light L. Referring to FIG. The second interval is calculated from the moving speed of the tip Pa of the paper P passing through the nip N and the distance between the nip N and the photosensitive medium 115 . The operation of the optical scanning device 127 and the photosensitive medium 115 is not significantly affected by the irregular time delay operation of the electronic clutch 192, thereby minimizing the error between the actual position and the expected position of the image printed on the paper P.

If the paper arranging device 150A is installed in the electrophotographic image forming apparatus, the error between the expected position and the actual position of the image formed on the paper is minimized, thereby improving the quality of printing. In addition, the paper arranging device 150A requires one sensor and one lever, thereby reducing manufacturing cost.

12 to 17 show a paper arranging device 150B according to another embodiment of the present invention. Compared with the paper arranging device 150A of FIGS. 7 to 11 , the paper arranging device 150B of FIGS. 12 to 17 further includes a second photosensor 200 installed to be spaced from the first photosensor 160 . The first and second photosensors 160 and 200 are upper and lower photosensors positioned along the circumference of a circle centered at the pivot 168 of the lever 165 . Similar to the first photoelectric sensor 160, the second photoelectric sensor 200 is electrically connected to the controller 190, and generates third and fourth sensing signals when detecting the position of the paper P, and transmits the third and fourth sensing signals to controller 190 .

The operation of the paper arranging device 150B of FIGS. 12 to 17 will now be described in detail. Referring to FIG. 13 , when the lever 165 is in the initial position, the first end 166 of the lever 165 is positioned directly below the nip N, and the second end 167 of the lever 165 is positioned above the first photoelectric sensor 160 . Until the paper P is conveyed upwards and the tip Pa of the paper P is in contact with the first end 166 of the control rod 165, the electronic clutch 192 connects the driving roller 152 with the motor (not shown) according to the control signal output by the controller 190, thereby preventing Drive roller 152 and guide roller 154 are rotated.

Referring to FIG. 14 , when the tip Pa of the paper P pushes the first end 166 of the lever 165 upward to the first position, the lever 165 rotates clockwise to rotate the second end 167 of the lever 165 downward. Therefore, the second end 167 enters the slit 161 (see FIG. 12 ) of the first photosensor 160 , and laser light emitted from the light emitting unit (not shown) of the first photosensor 160 is blocked by the second end 167 . In this case, the first photoelectric sensor 160 determines that the tip Pa of the paper P is approaching the nip N, and generates a first sensing signal.

Then, the tip Pa of the paper P is stopped and curled by the nip N, so that the paper P is arranged. The first sensing signal output from the first photosensor 160 is transmitted to the controller 190 . At a first time interval after the controller 190 receives the first sensing signal, the controller 190 generates a control signal, and transmits the control signal to the electronic clutch 192 , so that the electronic clutch 192 operates. When the electronic clutch 192 operates, the transmission roller 152 is connected to the motor, and the transmission roller 152 and the guide roller 154 installed adjacent to the transmission roller 152 rotate, thereby moving the paper P.

Referring to FIG. 15 , when the first end 166 of the lever 165 is pushed by the tip Pa of the paper P passing through the nip N, the lever 165 rotates continuously. As shown in FIG. 16 , when the first end 166 reaches the second position where the paper P advances farther than the first position, the second end 167 does not block the laser light emitted by the light emitting unit of the first photosensor 160 . Thus, the light receiving unit of the first photosensor 160 receives light, and the first photosensor 160 determines that the tip Pa of the paper P has passed through the nip N, and generates a second sensing signal.

The second sensing signal output from the first sensor 160 is transmitted to the controller 190 . At a second interval after receiving the second sensing signal, the controller 190 generates and transmits a control signal so that the light scanning device 127 and the photosensitive medium 115 (see FIG. 6 ) operate to expose the photosensitive medium 115 to light L. Referring to FIG. The second interval is calculated from the moving speed of the nip N of the paper P passing through the nip N and the distance between the tip Pa and the photosensitive medium 115 . Accordingly, the operation of the optical scanning device 127 and photosensitive medium 115 is not significantly affected by the irregular time-delay operation of the electronic clutch 192, thereby minimizing the error between the actual position and the expected position of the image formed on the paper P.

When the paper P moves upward, the first end 166 of the lever 165 reaches a third position deviated from the paper P path. Referring to FIG. 17 , the second end 167 of the lever 165 enters the second slit 201 of the second photosensor 200 at the third position (see FIG. 12 ). In this case, the laser light emitted by the light emitting unit (not shown) of the second photosensor 200 is blocked by the second end 167 and not received by the light receiving unit (not shown) of the second photosensor 200 . Therefore, the second photoelectric sensor 200 determines that the paper P is passing through the nip N, and generates a third sensing signal.

When the end Pb of the paper P passes through the nip N, the lever 165 is rotated in the counterclockwise direction by the spring 177 until the lever 165 hits the stopper 175 and stops. When the control lever 165 stops, the control lever 165 returns to the original position, as shown in FIG. 13 . In this case, the second end 167 of the lever 165 does not block the light emitted by the light emitting unit of the second photosensor 200 , and the light is input to the light receiving unit of the second photosensor 200 . Then, the second photoelectric sensor 200 determines that the end Pb of the paper P has passed through the nip N, and generates a fourth sensing signal.

The third and fourth sensing signals are successively generated by the second photosensor 200 and transmitted to the controller 190 . The controller 190 may calculate the length of the paper P from the moving speed of the paper P and the interval between the third and fourth sensing signals. When the controller 90 does not receive the fourth sensing signal within a predetermined period of time after receiving the third sensing signal, the controller may determine that a paper jam has occurred during the movement of the paper P, and transmit a A message is sent to a display panel (not shown) of the electrophotographic image forming apparatus 100 to inform the user that a paper jam has occurred.

If the paper arranging device 150B is installed in the image forming apparatus, the error between the actual position and the expected position of the image formed on the paper is minimized, thereby improving the quality of printing.

The above-described paper arranging device 150B can measure the length of supplied paper and detect paper jams, so that the image forming apparatus does not require additional components to perform these operations, thereby reducing manufacturing costs.

While certain embodiments of the present invention have been shown and described, those skilled in the art will appreciate that, without departing from the principles and spirit of the invention and the scope defined by the appended claims and their equivalents, it will be understood that, Various changes are made to these embodiments.

This application claims priority over Korean Patent Application No. 10-2004-81356 filed Oct. 12, 2004 and Korean Patent Application No. 10-2004-106546 filed Dec. 15, 2004 right, the entire disclosure content of which is hereby incorporated by reference.

Claims (18)

1. a paper cloth that is used for electrophotographic image forming is put device, and it comprises:

A mutual live-roller and the deflector roll of disposed adjacent to form a roll gap;

Detection is along a first sensor of the position of the paper of a paper path movement;

Control lever with one first end and one second end, described first end extends to the circumference of described roll gap to stop towards the tip of the described paper of described roll gap motion, described second end extends to the circumference of described first sensor, and described control lever is rotatable with respect to first end and the predetermined pivot between second end of described control lever; With

One second sensor, described second sensor and described first sensor separate, position with the paper that detects described motion, wherein, when first end of described control lever by the tip pushing of the paper of described motion and when arriving a primary importance, described first sensor judges that the tip of described paper is entering described roll gap and producing one first transducing signal, and

When first end of described control lever by the tip pushing of the paper of described motion and arrive when described paper path is distal to a second place of described primary importance, the tip that described first sensor is judged described paper is by described roll gap and produce one second transducing signal

Wherein, when first end of described control lever by the tip pushing of described paper and arrive when departing from one the 3rd position in described paper path, described second sensor is judged described paper by described roll gap and produce one the 3rd transducing signal, and

When first end of described control lever when described the 3rd position turns back to an initial position, the end that described second sensor is judged described paper is by described roll gap and produce one the 4th transducing signal.

2. paper cloth as claimed in claim 1 is put device, and wherein, the time of described live-roller rotation is according to determining from first transducing signal of described first sensor output.

3. paper cloth as claimed in claim 1 is put device, wherein, is formed with time that the photosensitive medium of the described electrophotographic image forming of sub-image exposes on it according to determining from second transducing signal of described first sensor output.

4. paper cloth as claimed in claim 1 is put device, wherein, also comprises a limiter of the anglec of rotation that is used to regulate described control lever.

5. paper cloth as claimed in claim 1 is put device, wherein, described control lever elastic biasing makes first end of described control lever can turn back to an initial position, at described initial position, first end of described control lever stops towards the tip of the described paper of described roll gap motion.

6. paper cloth as claimed in claim 1 is put device, and wherein said first sensor comprises a photoelectric sensor.

7. paper cloth as claimed in claim 1 is put device, and wherein, described first and second sensors comprise photoelectric sensor.

8. paper cloth as claimed in claim 1 is put device, and wherein, described first and second sensors are the circumferential registration of the circle at center along the described pivot with described control lever.

9. paper cloth as claimed in claim 1 is put device, and wherein, at least one in described live-roller and the described deflector roll comprises a kerf part, and described control lever is arranged in the described notch portion.

10. paper cloth as claimed in claim 1 is put device, and wherein, the described primary importance and the described second place are about described roll gap positioned opposite.

11. paper cloth as claimed in claim 1 is put device, wherein, described primary importance, described roll gap and the described second place are arranged in order along described paper path.

12. an electrophotographic image forming, it comprises:

Emission is corresponding to a light scanning apparatus of the light of picture signal;

One photosensitive medium when described photosensitive medium is exposed to the light time of being launched by described light scanning apparatus, forms a sub-image on the described photosensitive medium;

One paper cloth is put device, and it comprises:

Be positioned at a live-roller and a deflector roll of described photosensitive medium front along a paper path, the mutual disposed adjacent of described live-roller and deflector roll to be forming a roll gap,

Detect motion paper the position a first sensor and

Control lever with first end and second end, described first end extends to the circumference of described roll gap to stop towards the tip of the described paper of described roll gap motion, described second end extends to the circumference of described first sensor, described control lever be mounted to respect to the predetermined pivot of one between first end of described control lever and second end rotatable and

Separate one second sensor with described first sensor with the position of the paper that detects described motion, wherein, when first end of described control lever by the tip pushing of described paper and when arriving a primary importance, described first sensor judges that the tip of described paper is entering described roll gap and producing one first transducing signal, and

When an end of described control lever by the tip pushing of described paper and arrive when described paper path is distal to a second place of described primary importance, the tip that described first sensor is judged described paper is by described roll gap and produce one second transducing signal,

When first end of described control lever by the tip pushing of described paper and arrive when departing from one the 3rd position in described paper path, described second sensor is judged described paper by described roll gap and produce one the 3rd transducing signal, and

When first end of described control lever when described the 3rd position turns back to described initial position, the end that described second sensor is judged described paper is by described roll gap and produce one the 4th transducing signal; With

One controller, described controller are respectively according to the time of controlling described live-roller rotation from first transducing signal and second transducing signal of described first sensor output and the time of described photosensitive medium exposure.

13. electrophotographic image forming as claimed in claim 12, wherein, described paper cloth is put device and is also included the clutch coupling that the power that selectively a drive source is produced is sent to described live-roller, and

According to first transducing signal from described first sensor output, described controller is controlled the time of described live-roller rotation by operating described clutch coupling.

14. electrophotographic image forming as claimed in claim 12, wherein, according to second transducing signal from described first sensor output, described controller is controlled the time of described photosensitive medium exposure by operating described light scanning apparatus and photosensitive medium.

15. electrophotographic image forming as claimed in claim 12, wherein, described paper cloth is put device and is also comprised:

Be used to regulate a limiter of the anglec of rotation of described control lever.

16. electrophotographic image forming as claimed in claim 12, wherein, described control lever elastic biasing makes first end of described control lever turn back to its initial position, at described initial position, first end of described control lever stops towards the tip of the described paper of described roll gap motion.

17. electrophotographic image forming as claimed in claim 12, wherein, described first sensor comprises a photoelectric sensor.

18. electrophotographic image forming as claimed in claim 12, wherein, described first and second sensors comprise photoelectric sensor.

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