KR20050068065A - Image forming apparatus and its controlling method - Google Patents

Abstract

An image forming apparatus and a control method thereof, comprising: a light scanning machine for scanning light corresponding to image information to a photosensitive medium so that supply of paper and formation of an image are synchronized; and a developing device for developing an electrostatic latent image formed by the light scanning machine; An image forming apparatus comprising a transfer machine for transferring an image formed on a photosensitive medium to paper, the image forming apparatus comprising: an engine driver for driving a light scanning machine and a developing device; The distance (or arrival time) from the pick-up position (A) of the paper to the position (C) where the image is transferred to the paper (or the time of arrival) is the distance from the first optical scanning device (B) to the position (C) where the image is transferred to the paper. A paper feeding unit which is longer than or equal to the arrival time and is installed on a predetermined position of the main body so that paper can be loaded; A remaining amount detecting unit for detecting a remaining amount of paper; And a controller for controlling the engine driver according to the detected paper remaining amount.

Description

Image forming apparatus and its controlling method

The present invention relates to an image forming apparatus and a control method thereof, and more particularly, to a photosensitive medium due to lack of paper during continuous printing by synchronizing pickup of paper and scanning of the first optical scanner in a tandem image forming apparatus. The present invention relates to an image forming apparatus and a method of controlling the same, which are capable of preventing contamination.

In general, in an image forming apparatus, an image recording surface of a photosensitive medium such as a photosensitive belt or a photosensitive drum is charged, and the potential level is changed by light selectively scanned on the image recording surface to form an electrostatic latent image. Then, the charged developer is attached to the latent electrostatic image position to form an image.

1 shows a typical wet printing machine.

Referring to the drawings, the photosensitive medium 1 rotates the caterpillar while being supported by the driving roller 3a, the steering roller 3b, the transfer backup roller 3c, and the like. The electrostatic latent image remaining on the image recording surface of this photosensitive medium 1 is removed from the erasure 11. The video recording surface is then charged uniformly to a predetermined potential while passing through the corona charging device 13.

The image recording surface of the photosensitive medium 1 charged to a predetermined electric potential in this manner is selectively photosensitive by a laser beam scanned from the optical scanner 15, which is collectively referred to as a laser scan unit (LSU). The potential level is changed to form an electrostatic latent image. The developing unit 16 is formed on the image recording surface of the photosensitive medium 1 with a predetermined color supplied from the mixed container 25, for example, yellow (Y), magenta (M), cyan (C) or black (K) developer. Develop an electrostatic latent image. That is, each of the color developing solutions is pumped from the mixing container 25 to the developing roller 17 installed close to the image recording surface of the photosensitive medium 1 by the pump 26, and according to the rotation of the developing roller 17 Attached to the electrostatic latent image position of the photosensitive medium 1 to form respective color images. In addition, the developing solution falling into the developing device 16 in the developing process is recovered to the mixed container 25. The mixed container 25 is filled with a color developer in which toner charged at a predetermined potential and a liquid carrier are mixed at an appropriate concentration. Here, reference numeral 20 denotes an ink cartridge containing a high concentration of developer, and reference numeral 27 denotes a liquid carrier tank. By adjusting the supply amounts of the high concentration developer and the carrier supplied from the ink cartridge 20 and the carrier tank 27, the mixed container 25 is filled with a developer at an appropriate level. Here, the mixing container 25 and the developing device 16 may be provided integrally.

The photosensitive medium 1 on which the color image is formed on the image recording surface is dried by the drying unit 28 through the above developing process, and the liquid carrier in the developer is removed from the image recording surface of the photosensitive medium 1 so that only toner particles remain. do. Then, the image made of the toner attached to the photosensitive medium 1 is transferred to the transfer roller 29, and then printed on the paper 30 passed between the transfer roller 29 and the fixing roller 31.

The paper 30 is picked up by the feeding rollers 39a and 39b from the paper feeding unit 35 mounted on the printer and moved along the guide unit 37.

In the case of continuous printing using the paper 40 supplied from the paper feeder 35, the image forming apparatus stops when the paper 40 is not in the paper feeder 35. At this time, the image to be transferred to the paper 40 to be fed next remains on the photosensitive medium 1. The image remaining on the photosensitive medium 1 must be removed before operating the printer again. In other words, the image remaining on the photosensitive medium 1 is regarded as contamination. As such, the reason why the image remains on the photosensitive medium 1 is the distance from the time point B at which the first optical scanner 15 is scanned to the place C where the image is transferred onto the paper 40 (hereinafter referred to as image transfer distance). This is because the distance from the pick-up position A of the paper feeder 35 to the place C where the image is transferred to the paper 40 (hereinafter referred to as paper feed distance) is shorter than that of the paper 40.

Therefore, the cleaning operation time is required to remove the image remaining on the photosensitive medium after the printer is stopped, and the life of the cleaning unit is shortened as the frequency of the cleaning operations increases.

In addition, since the photosensitive medium has to be rotated a predetermined number of times during the cleaning operation, the life of the photosensitive medium is shortened, and ink is unnecessary to form an image remaining on the photosensitive medium even after the image forming apparatus is stopped.

The present invention has been proposed to solve the above problems, and an object of the present invention is to synchronize the pickup of the paper and the scanning of the first optical scanner so that there is no residual image due to the lack of paper during continuous printing, thereby preventing contamination of the photosensitive medium. It is to provide an image forming apparatus and a control method thereof that can be prevented.

Another object of the present invention is to provide an image forming apparatus and a method of controlling the same, which eliminates the need for a cleaning operation by preventing residual images from being generated on the photosensitive medium when paper runs out.

In order to achieve the above object, the image forming apparatus according to the present invention,

An image forming apparatus comprising: a photoconductor for scanning light corresponding to image information onto a photosensitive medium; a developing device for developing an electrostatic latent image formed by the photoconductor; and a transfer device for transferring an image formed on the photosensitive medium onto a paper. An engine driver for driving the optical scanner and the developer; The distance (or arrival time) from the pick-up position of the paper to the position where the image is transferred to the paper is longer than or equal to the distance (or arrival time) from the first optical scanner dice to the position where the image is transferred to the paper, A paper feeding unit installed at a position to load paper; A remaining amount detecting unit for detecting a remaining amount of the paper; And a controller configured to control the engine driver based on the detected paper remaining amount.

In this case, the control unit preferably controls to stop the operation of the first optical scanner by controlling the engine driver if there is no detected paper remaining amount.

On the other hand, the control method of the image forming apparatus according to the present invention,

A control method of an image forming apparatus comprising: a photoscanner for scanning light corresponding to image information onto a photosensitive medium; a developing machine for developing an electrostatic latent image formed by the photoconductor; and a transfer machine for transferring an image formed on the photosensitive medium to paper. The control method according to claim 1, further comprising the steps of: a) detecting the remaining amount of paper in the paper feeder; b) performing image forming if there is remaining paper, and stopping the operation of the first optical scanner and supplying paper if there is no remaining paper; and c) determining whether the preset number of prints and the number of printed prints are the same and terminating the image forming job in the same case, and repeating steps a), b), and c) in other cases.

Hereinafter, exemplary embodiments of an image forming apparatus and a control method thereof according to the present invention will be described in detail with reference to the accompanying drawings.

2 is a schematic structural diagram of an image forming apparatus according to the present invention.

Referring to the drawings, the image forming apparatus according to the present invention includes the photosensitive medium 1, the optical scanning machine 15, the developing device 18, the transfer machines 29 and 31, the paper feeder 35, and the remaining amount detection unit 45. Include.

The optical scanner 15 and the developer 18 are assigned to each color and are controlled by an engine driver (not shown) driven under the control of a controller (not shown).

The optical scanner 15 scans light corresponding to image information to the photosensitive medium 1, and the developing unit 18 develops an electrostatic latent image formed on the photosensitive medium 1 by the optical photoreceptor 15. .

The transfer devices 29 and 31 transfer the image formed on the photosensitive medium 1 onto the paper 40.

The paper feeding unit 35 is installed on a predetermined position of the main body so as to load the paper 40, and the remaining amount detecting unit 45 for detecting the remaining amount of the paper 40 on one side of the paper feeding unit 35. Is installed.

The remaining amount of paper information detected by the remaining amount detecting unit 45 is transmitted to a controller (not shown) to control the engine driver (not shown) accordingly. If there is no remaining amount of paper detected from the remaining amount detecting unit 45 Upon receiving the information, the controller (not shown) stops the operation of the first optical scanner 15a by controlling the engine driver (not shown).

Here, of course, the remaining amount detection unit 45 may use an optical sensor, a piezoelectric element or a generally known sensor.

On the other hand, the paper 40 loaded on the paper feeder 35 is guided to the transfer machines 29 and 31 along the guide portion 37. At the time B at which the first optical scanner 15a is scanned, the image is printed. The distance from the pick-up position A of the paper feeder 35 to the place C where the image is transferred to the paper 40 is greater than or equal to the distance to the place C to which the paper 40 is transferred. The guide portion 37 is formed to be.

That is, the guide portion 37 is formed such that the image conveying distance BC is longer than or equal to the sheet conveying distance AC, but the present invention is not limited to the conveying distance.

According to another embodiment of the present invention, the paper 40 of the paper feeder 35 is larger than the arrival time from the time point B at which the first optical scanner 15a is scanned to the place C where the image is transferred to the paper 40. It is controlled so that the arrival time from the pick-up position A to the position C where the image is transferred onto the paper 40 is longer or equal. Irrespective of the length or length of the above paper feed distance AC or the image feed distance BC, by adjusting the rotation period of the photosensitive belt 1 or by adjusting the rotation speed of the feeding roller 39, a paper or image transfer machine (29,31) The arrival time is controlled.

3 is a block diagram illustrating a method for controlling an image forming apparatus according to the present invention. Referring to the drawings, the method for controlling an image forming apparatus according to the present invention includes: receiving a continuous image forming signal (S100) and detecting a remaining amount of paper; A step S110 and a normal print mode performing step and a pollution prevention mode performing step are included.

The paper remaining amount detecting step (S110) detects the remaining amount of paper in the paper feeder 35. If the remaining amount of paper is left, the normal printing mode is performed. If the remaining amount of paper is left, the contamination prevention mode is performed.

In the normal printing mode, an image forming step (S120) of forming an image on the photosensitive medium 1 and printing the formed image on the paper 40, and the number of sheets printed in the image forming step (S120) are preset If it is determined that the number is the same as the number of prints, the operation is terminated. If the number is not the same, the print quantity comparison step S130 returns to the paper remaining amount detection step S110.

As such, if the remaining amount of paper is continuously measured by the remaining amount detection unit 45 while the printing operation is in progress in the normal printing mode, the remaining amount of paper is stopped.

When the information indicating that there is no paper is transmitted from the remaining amount detecting unit 45 to the controller (not shown), the controller (not shown) stops the operation of the first optical scanner 15a (S112).

At this time, all printing operations are paused, and when the user additionally supplies the paper by notifying the paper shortage status or by generating a beeping sound (S114), the printer proceeds to the normal printing mode through the remaining paper detection step (S110). .

In the image forming apparatus of the present invention, the distance (or arrival time) from the pick-up position (A) of the paper to the position (C) at which the image is transferred onto the paper is determined by the dice (B) of the first optical scanner 15a. Since the image is formed to be longer than or equal to the distance (or arrival time) to the position C to be transferred, when printing is interrupted in the pollution prevention mode, no image remains on the photosensitive medium 1.

An operation of an image forming apparatus and a control method thereof according to an exemplary embodiment of the present invention having the above configuration will be described.

First, when the control unit receives the continuous image forming signal, the control unit receives the remaining amount of paper remaining information from the paper feeding unit 35 from the remaining amount detecting unit 45.

As a result, if there is a remaining amount of paper, an image is formed by performing a normal print mode (S120), and the remaining amount of paper detection step (S110) and image forming step (S120) are performed until the preset number of prints matches with the number of printed sheets. Repeatedly executes the print job.

During this repetition process, if the remaining amount of paper runs out, the contamination prevention mode is performed. The controller (not shown) stops the operation of the first optical scanner 15a by controlling the engine driver (not shown) when there is no remaining paper (S112), and suspends all printing operations.

When the user supplies the paper again (S114), the pollution prevention mode ends and the normal print mode is performed through the paper remaining amount detection step (S110).

In the image forming apparatus of the present invention, since the paper feeding distance (or time) is formed to be longer than or equal to the image feeding distance (or time), the image forming operation starts at the same time as the paper feeding or after the paper feeding. Therefore, if there is no remaining paper, the image forming job is not started and there is no remaining image on the photosensitive medium 1 after the printing job is stopped.

As described above, the image forming apparatus and its control method according to the present invention are formed such that the paper conveying distance (or time) is longer than or equal to the image conveying distance (or time) so that the image forming operation is performed simultaneously with or after the paper feeding. By doing so, when printing is stopped due to lack of paper, no image remains on the photosensitive medium, thereby preventing the contamination of the photosensitive medium.

In addition, it is possible to prevent unnecessary consumption of ink or toner, and there is no need for a cleaning operation, thereby reducing the life of the cleaning device.

In the detailed description of the present invention as described above, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined by the claims below and equivalents thereof.

1 shows a typical wet press,

2 is a schematic configuration diagram of an image forming apparatus according to the present invention;

3 is a block diagram showing a control method of the image forming apparatus according to the present invention.

<Explanation of symbols for the main parts of the drawings>

1: photosensitive medium 15: Gwangju fraud

16,18 developing machine 17 developing roller

25: mixed container 29, 31: transfer machine

30,40: paper 35: paper feed unit

37: guide part 39: feeding roller

45: remaining amount detection unit

Claims (4)

An image forming apparatus comprising: a photoconductor for scanning light corresponding to image information onto a photosensitive medium; a developing device for developing an electrostatic latent image formed by the photoconductor; and a transfer device for transferring an image formed on the photosensitive medium onto a paper. An engine driver for driving the optical scanner and the developer; The distance from the pick-up position (A) of the paper to the position (C) where the image is transferred to the paper is longer than or equal to the distance from the first optical scanner dice (B) to the position (C) where the image is transferred to the paper. A paper feeding unit installed on a predetermined position of the paper so as to load paper; A remaining amount detecting unit for detecting a remaining amount of the paper; And And a controller which controls the engine driver in accordance with the detected paper remaining amount. An image forming apparatus comprising: a photoconductor for scanning light corresponding to image information onto a photosensitive medium; a developing device for developing an electrostatic latent image formed by the photoconductor; and a transfer device for transferring an image formed on the photosensitive medium onto a paper. An engine driver for driving the optical scanner and the developer; The arrival time from the pick-up position (A) of the paper to the position (C) where the image is transferred onto the paper is longer than or equal to the arrival time from the first optical scanning device (B) to the position (C) where the image is transferred onto the paper. A paper feeding part installed on a predetermined position of the main body to load paper; A remaining amount detecting unit for detecting a remaining amount of the paper; And And a controller which controls the engine driver in accordance with the detected paper remaining amount. The method according to claim 1 or 2, And the control unit controls to stop the operation of the first optical scanner by controlling the engine driving unit when the detected paper remaining amount is not present. A control method of an image forming apparatus comprising: a photoscanner for scanning light corresponding to image information onto a photosensitive medium; a developing machine for developing an electrostatic latent image formed by the photoconductor; and a transfer machine for transferring an image formed on the photosensitive medium to paper. In the control method is a) detecting the remaining amount of paper in the paper feeding unit; b) performing image forming if there is remaining paper, and stopping the operation of the first optical scanner and supplying paper if there is no remaining paper; c) determining whether the preset number of prints and the number of printed prints are the same and terminating the image forming operation in the same case, and repeating steps a), b), and c) in the other case. Control method of the forming apparatus.