JPS6296972A - Copying device - Google Patents

Abstract

PURPOSE:To prevent the degradation of a recording medium by detecting the temperature of a form to control a copying operation on the way where the form is carried to a transfer position. CONSTITUTION:The temperature of the form supplied from an intermediate tray 12 is detected by a temperature detector 32 arranged near a carrying roll 31 provided in a carrying path 30. The temperature detector 32 is provided with a temperature detecting element such as a thermistor and detects the temperature of the form at which a photosensitive body 1 is not heated neither crystallized. When the temperature detector 32 detects that the temperature of the form is higher than a prescribed value, the driving of various rolls for form carrying is stopped and the copying operation, especially, the operation of the process where an image is formed on the photosensitive body 1 is stopped. When the temperature detector 32 detects that the temperature of the form is lower than the rescribed value, the driving of various rolls of the carrying system is made possible and the copying operation is performed. Thus, the temperature rise of the recording medium is prevented.

Description

[Detailed Description of the Invention] Technical Field> The present invention relates to a copying apparatus that forms an image of a copy document or the like on a recording medium and transfers the formed image to a sheet of paper that is being conveyed appropriately to make a copy. In particular, the present invention relates to copying control of this copying apparatus.

<Prior Art> An electrophotographic copying apparatus uniformly charges a photoreceptor having a photoconductive layer, which is a recording medium, and then irradiates the photoreceptor with a light image of a copy document to form an electrostatic latent image on the surface of the photoreceptor. This latent image is developed with a colored pigment toner, the developed image is appropriately transferred to a sheet of paper, and then the image on the sheet of paper is fixed through a fixing section to perform copying. Heat fixing is particularly widely used as a device for fixing the image on the paper.Here, in a copying device such as the one described above, when copying is performed only on one side of the paper, the paper is not fixed to the heat fixing device. It passes through only once and is carried out of the copying machine. In other words, the paper passes through the transfer position of the recording medium only once. On the other hand, if the copying machine has automatic duplex copying function,
After the copied image is fixed on the front side of the paper, the paper is transported to a transfer position to form an image on the back side again. The paper that has been copied on its surface in this way passes through a heat fixing device once,
It will be transported to the transfer position again. At this time, when back side copying is performed, the paper is heated considerably by the heat fixing device, and when the paper is conveyed as it is to the transfer position, it heats the photoreceptor, and the temperature of the photoreceptor itself also rises. For this reason, when the photoreceptor reaches a certain temperature or higher, it crystallizes and deteriorates, making it impossible to form a normal copy image.

Note that the above-mentioned disadvantages occur not only when double-sided copying is performed, but also when the paper is heated for some reason and is conveyed to the transfer position where it comes into contact with the photoreceptor during single-sided copying.

Purpose of the present invention: The purpose of the present invention is to prevent a recording medium from being heated by paper being conveyed, and in particular, by controlling paper conveyance and copying operations, it is possible to prevent the temperature rise of the recording medium. The purpose is to prevent.

<Example> FIG. 1 is a sectional view showing a copying apparatus according to the present invention.

In the figure, 1 is a drum-shaped photoreceptor having a photoconductive layer such as Se-U (Se), 2 is a corona discharger that uniformly charges the surface of the photoreceptor, and 3 is placed on an original platen 4. an exposure position where reflected light from a placed original is image-exposed via an optical means 5; a developing device 6 which develops an electrostatic latent image on a photoreceptor;
7 is a transfer corona discharger for transferring the developed image on the photoreceptor to the paper conveyed along the conveyance path; 8 is a peeling corona discharger for electrostatically peeling the paper from the photoreceptor; 9 removes toner remaining on the surface of the photoreceptor. The paper conveyed to the transfer position facing the transfer corona discharger 7 is accommodated in the paper feed force cell 1-11 or the intermediate tray 12 for double-sided copying or composite copying. paper feeder)
Reference numeral 11 is detachably provided on the paper feed of the main body of the copying apparatus. This paper feed section is provided with a paper feed roller 13 that is driven in accordance with a paper feed command, corresponding to the paper feed roller 11 that is attached. The paper in the cassette 1-11 is fed as the paper feed roller 13 is driven, and its feeding is temporarily stopped by the synchronous roller 14 while being conveyed to the transfer position.

The synchronous roller 14 transports the paper to the transfer position in synchronization with the rotating photoreceptor l.

That is, the synchronous roller 14 controls the conveyance of the paper so that the image forming edge of the photoreceptor 1 and the paper edge coincide at the transfer position. In particular, the paper is previously conveyed to the synchronous roller 14 along with the copying operation, and when the photoreceptor l rotates to a predetermined position, the sheet is driven again to the transfer position by the synchronous roller 14.

After the transfer, the paper is electrostatically peeled off from the photoreceptor 1 by the action of the peeling corona discharger 8. This peeled paper is
The image is transported to the heat fixing roller 16 by the transport belt 15Vc. The conveyance bell 1-15 guides the paper to the heat fixing roller 16 by suctioning the back surface of the paper (the opposite surface to which the image has been transferred) by air suction from the air suction means. Further, the constant heat roller I6 mainly thermally fixes an image (one image of toner) on the surface while conveying the paper, and is provided with a heating source at least on the side facing the image. The heat fixing roller 16
The paper passing through is then delivered by a paper ejection roller 17 to a paper ejection tray 18 provided to protrude outside the apparatus.

In the middle of the conveyance path between the paper discharge roller 17 and the paper discharge tray 18, there is a switching gate 19 for switching the paper conveyance direction.
is movably provided. The switching gate 19 is a switching gate that guides paper whose front side has been copied during double-sided copying or paper for composite copying to the conveyance path 20, and guides other copy papers to the paper output tray 18. be. A large number of conveyance rollers 21 are arranged in the conveyance path 20 for conveying paper, and gates 22 and 28 are provided along the way for separating paper for composite copying and paper for double-sided copying. is provided. In particular, the gate 22 is positioned as shown in the figure during composite copying, and guides the transported paper to the transport path 24 leading to the intermediate tray 12 described above. When duplexing, the gates 22 and 2
3 is switched from the position shown in the figure and guides the paper to the reversing conveyance path 25. This reversing conveyance path 25 is provided with a detection device 26 that detects the paper. The detection device 26 reverses the rotation of the conveyance roller 27 by detecting the trailing edge of the paper, and also reverses the rotation of the conveyance roller 27 and closes the gate 2.
3. Return to the position shown in the figure. As a result, the paper is guided to the conveyance path 24, and then guided to the intermediate tray 12 via the conveyance rollers 28.

As described above, the intermediate tray 12 is provided in the conveyance path to temporarily store paper in order to perform duplex or composite copying on the paper. This intermediate tray 12 is provided with a paper feed roller 29 for feeding the stored paper sheets one by one to the transfer position of the photoreceptor l. The paper fed from the intermediate tray 1273 is conveyed via the recording path 30 to the conveyance path where the synchronous roller 14 is arranged, and is temporarily stopped by the synchronous roller 14. .

In the copying apparatus configured as described above, the present invention detects the temperature of the paper stored in the intermediate tray 12 to control the copying operation. That is, the temperature of the paper fed from the intermediate tray I2 is detected by the temperature detection device 32 disposed near the conveyance roller 31 provided in the conveyance path 30Vc. The temperature detecting device 32 is equipped with a temperature detecting element such as a thermistor, and detects the temperature of the paper such that the photoreceptor 1 is not heated and crystallized. For example, if the photoconductor l is 6 and the photoconductive layer is selenium (Se), 17
If heated above 8°C, there is a risk of crystallization. Therefore, the temperature detection device 8 detects whether the paper temperature is 178°C or higher.
2 will be detected. If this temperature detection device 32 detects that the temperature is higher than the above-mentioned specified temperature, it uses this detection signal to stop driving the various rollers that transport the paper, and performs the copying operation, especially forming an image on the photoreceptor l. Stop the process that you want to run. When the temperature detection device 32 detects that the above-mentioned paper temperature has become below the specified temperature, it enables the various rollers of the conveyance system to be driven, and also activates the copying operation.

FIG. 2 is a block diagram showing an example of a control circuit configuration according to the present invention. ROM 40 that stores a control program for copying, RAM 41 and R that stores necessary data.
A control circuit 43 consisting of a CPU 42 that sequentially executes the programs of the OM 40 receives various inputs output from the copying apparatus via an input interface 44, and outputs signals to control each load for copying according to the inputs to an output interface 45. Output via. The control circuit 43 inputs the signal 11 detected by the temperature detection device 32 when the temperature is higher than the specified temperature, and outputs the signal 01 to stop driving the various rollers of the conveyance system that conveys the paper, especially the conveyance roller 31. At this time, the control circuit simultaneously stops the operation for forming an image on the photoreceptor l.

FIG. 3 is a flowchart showing the control procedure shown in FIG. 2. As shown in the figure, first, in step S1, it is determined whether or not the copying machine performs backside copying in a double-sided copying mode. In short, this is not limited to double-sided copying, but also in composite copying, since once the heat fixing roller 16 is energized and stored in the intermediate tray 12, if it is detected whether or not there is paper in the intermediate tray 12, step S1 82.

Then, in step S2, the paper feeding roller 29 is driven to feed one sheet of paper in the intermediate tray 12. After this paper is fed, the paper is transferred to the transport roller 31
During the conveyance, the paper temperature is detected by the temperature detection device 32. Therefore,
As shown in step S3, a determination is made as to whether or not the temperature detection device 32 has detected a temperature equal to or higher than the specified temperature (force 1). ), the copying operation is temporarily interrupted. After this process, the detection state of the temperature detection device 32 is determined again and the paper temperature is waited for to become below the specified temperature.

If the temperature detection device 32 detects that the temperature has become below the regulation temperature, the process proceeds to steps S, 75 to S5, the conveying roller 3I is driven, and the copying operation is started. This results in
An image is formed on the back side of the paper.

When this copying is completed, the process returns to step S1 to feed the next sheet.

According to the embodiments described above, the temperature of the paper fed from the intermediate tray 12 is detected in double-sided or composite copying, but the temperature of the paper fed from the paper feed cassette 11 is not limited to this. The copying operation may also be controlled by

Effects> According to the copying apparatus of the present invention, the paper temperature is detected while the paper is being conveyed to the transfer position, and the copying operation is controlled based on this detection. Since the recording medium is not heated, deterioration of the recording medium can be prevented, and a normal image can always be formed.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the structure of a copying apparatus according to the present invention;
Figure 2 is a block diagram showing an uninvented control circuit configuration;
The figure is a flowchart showing the control procedure in FIG. 1: Photoreceptor, 2: Corona discharger, 3: Exposure position, 5 Developing device, 7: Transfer corona discharger, 9: Cleaning device, IO: Static elimination lamp, 11: Paper feeding cassette, 12:
Intermediate tray, 13: Paper feed roller, 14: Synchronous roller, I
6: Heat 32: Temperature detection device, 43: Control circuit. Agent Patent Attorney Aihiko Fuku (and 2 others) Figure 1, 2r! :J

Claims (1)

[Claims] 1. In a copying device that performs copying by transferring an image formed on a recording medium to a medium that is appropriately conveyed along a conveyance path,
A temperature detection means for detecting the temperature of the paper is provided in the paper transport path to the position where the image formed on the recording medium is transferred,
The present invention is characterized in that a control means is provided which stops conveyance of the sheet and stops the copying operation when the temperature detection means detects a temperature higher than a predetermined temperature, and when the temperature is lower than the predetermined temperature, conveys the paper and continues the copying operation. Copying equipment.