JPH08166746A - Image forming device - Google Patents

Abstract

PURPOSE: To provide a means for preventing, in case form P is jammed before reaching a fixing device after the transfer of a toner image to the paper P, a user from soiling his hands and clothe when removing the paper, as in an image forming device of an electrophotographic system using toner, etc. CONSTITUTION: Paper detection sensors 3, 4, and 5 are disposed right behind a carry roller 8 in a carry path for the form P, a photoreceptor drum 1, and a fixing roller 2, respectively. When jamming is detected by the length of time that each of the sensors 3-5 connected to a microcomputer 11 is turned on from off or it is turned off from on, and when the form P exists between the sensors 4 and 5, the device shows a warning onto a liquid crystal display(LCD) 10 to warns a user of jamming.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus, and more particularly to an electrophotographic image forming apparatus using toner or the like.

[0002]

2. Description of the Related Art Conventionally, when a recording paper (hereinafter simply referred to as "paper") causes a paper jam (jam) during an image forming operation of an image forming apparatus of this type, the paper conveying means is stopped and jammed. It was displaying that it did.

[0003]

However, for example, in the process of the electrophotographic image forming apparatus, the toner on the paper is charged from the transfer of the toner image onto the paper until the fixing process of the image. It is in a state where it can be removed immediately when it is touched just by being attached. When jammed in the device, if the paper in that state is inside the main body, when the user removes the paper, there is a possibility that his / her hands or clothes may be soiled.

The present invention has been made in view of the above problems, and when there is a sheet before fixing processing as described above when jammed, a warning is given to the user to that effect. It is intended to provide a display means.

[0005]

Therefore, in the present invention, therefore, a conveying means for conveying the sheet, a transfer means for transferring the toner image onto the sheet, which is located in the middle of conveying the sheet, and the sheet. A first paper detection unit that is located downstream of the transfer unit during conveyance of the sheet, and that fixes the toner image transferred to the sheet, and detects whether the sheet has passed the transfer unit. Means, a second detecting means for detecting whether or not the paper has passed the fixing means, and a plurality of paper detecting means including the first paper detecting means and the first and second detecting means, Based on the outputs of the plurality of paper detecting means, a paper jam detecting means for detecting a paper jam, a stopping means for stopping the conveying means when the paper jam detecting means detects a paper jam, and a stopping means for operating the stopping means. The first inspection Determining means for determining whether or not the sheet exists between the means and the second detecting means, and the determining means, when the stopping means operates, the first detecting means and the second detecting means. By configuring the image forming apparatus to include a display unit that displays a warning indicating that there is an unfixed sheet when it is determined that the sheet is present between
It is intended to achieve the above object.

[0006]

With the configuration of the present invention as described above, a warning can be displayed when the paper before the fixing process is present at the time of paper jam, and the user can be warned.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments; FIG. 1 is a schematic view of the essential parts of an example of an electrophotographic image forming apparatus that best represents the features of the present invention, and FIG. The structural block diagram is shown. Reference numeral 1 is a photosensitive drum, 2 is a fixing roller, 3 and 4 are paper detection sensors, 6 is a paper cassette, 7 is a paper feeding roller, 8 is a conveying roller, and 9 is a registration roller.

Each sheet P in the sheet cassette 6 is conveyed from the sheet cassette 6 in the direction of the conveying roller 8 by the sheet feeding roller 7 and abuts on the registration roller 9 which is stopped,
The tip stops. The trailing edge is pushed by the conveying roller 8 to bend the sheet P. The conveyance roller 8 stops at the timing when the amount of this bending becomes an appropriate amount.

A toner image is formed on the photosensitive drum 1 that rotates during this time, and the registration roller 9 starts rotating at the timing when the leading edge of the toner image coincides with the leading edge of the sheet, and the sheet P is The toner image on the photosensitive drum 1 is conveyed to the rotating photosensitive drum 1, and the toner image on the photosensitive drum 1 is transferred onto the paper P. Next, the toner image on the sheet is rushed into the fixing roller 2 and is melted by heat to be fixed on the sheet. In FIG. 2, 10 is a liquid crystal display (LCD) for warning, which will be described later, 11 is a microcomputer, 12 is another sensor and switch group, and 13 is another load group.

When the sheet P is conveyed, the sheet detection sensors 3, 4 and 5 are sequentially passed. Each of these paper detection sensors 3, 4, 5 is set to be turned on when the paper P is present therein, and each of these paper detection sensors 3, 4, 5 is turned on.
Reference numerals 4 and 5 are respectively connected to the microcomputer 11, and when the microcomputer 11 is monitoring the timing when these are switched from off to on or from on to off, and a "jam" is generated when the timing is later than a predetermined timing. To detect.

The fact that the timing of these timings from OFF to ON is late means that the paper P is slow to be applied to the paper detection sensors 3, 4, and 5. Further, the time from the on state to the off state is delayed, and it means that it is slow for the paper P to come out of the paper detection sensors 3, 4, and 5. Also, these timings are
The paper detection sensor 3 is measured after the paper feed roller 7 starts to rotate. The paper detection sensors 4 and 5 are measured after the registration roller 9 starts to rotate.

The above is an example of an image forming apparatus having a conventionally known jam detecting device. In the present embodiment, further, there is a paper P between the paper detecting sensor 4 and the paper detecting sensor 5. It is characterized by detecting whether or not.

A flow chart of the operation sequence of the present embodiment is shown in FIG. 3; first, when the paper detection sensor 4 is turned on in step S1, the flag is turned on in step S2. That is, the flag is turned on when the paper P enters between the paper detection sensor 4 and the paper detection sensor 5.

When the sensor 5 is turned off in step S3, the flag is turned off in step S4. That is, the flag is turned off when the paper P is removed from between the paper detection sensor 4 and the paper detection sensor 5.
As a result, the fact that the flag is on means that there is the paper P between the paper detection sensor 4 and the paper detection sensor 5.

Further, when there is a sheet P between the sheet detection sensor 4 and the sheet detection sensor 5, an unfixed toner image is placed on the sheet P, and when it is touched, the toner adheres to a hand or clothes. Will be done.

When the occurrence of the above-mentioned jam is detected in step S5, and when this flag is turned on in step S6, "jam is detected" in step S7.
As shown in FIG. 4 with the illustration, "Please pay attention to the unfixed paper." A warning is displayed on the liquid crystal display (LCD) 10 to notify the user. If the flag is off in step S6, a normal jam display is displayed in step S8, "Jam. There is no unfixed paper".
It should be noted that these displays are merely examples, and it goes without saying that other display methods and warning sounds may be used.

[0017]

As described above, according to the present invention,
If a paper with an unfixed toner image is inside the machine when a paper jam occurs, a warning will be displayed to alert you, so you can prevent the hands and clothes from getting dirty without your knowledge. You can

[Brief description of drawings]

FIG. 1 is a schematic diagram of a main part configuration of an embodiment.

FIG. 2 is a configuration block diagram of FIG.

FIG. 3 is an operation sequence flowchart of the first embodiment.

FIG. 4 is a display example of a liquid crystal display unit.

[Explanation of symbols]

 1 Photosensitive Drum 2 Fixing Roller 3, 4, 5 Paper Detection Sensor 6 Paper Cassette 7 Feeding Roller 8 Conveying Roller 9 Registration Roller 10 Liquid Crystal Display 11 Microcomputer 12 Other Sensors, Switches 13 Other Loads

Claims (1)

[Claims] 1. A transport means for transporting a sheet, a transfer means for transferring the toner image to the sheet, which is located in the middle of the transport of the sheet, and a downstream side of the transfer means for transporting the sheet. Fixing means for fixing the toner image transferred to the paper, a first paper detecting means for detecting whether the paper has passed through the transfer means, and whether the paper has passed through the fixing means. Second detection means for detecting whether or not there is a plurality of paper detection means including the first paper detection means and the first and second detection means; and paper output based on the outputs of the plurality of paper detection means Paper jam detection means for detecting jams,
When the paper jam detecting means detects a paper jam, a stopping means for stopping the conveying means and a sheet between the first detecting means and the second detecting means when the stopping means operates. Determining means for determining whether or not there is a sheet, and when the determining means determines that the sheet exists between the first detecting means and the second detecting means when the stopping means operates, An image forming apparatus comprising: a display unit that displays a warning indicating that there is unfixed paper.