JPS62280139A - Electronic copying device - Google Patents

Abstract

PURPOSE:To prevent defective transcription, jamming and wrinkles from being caused, by adding means for measuring a resistance value of a transcribing paper sheet and means for humidifying or dehumidifying the transcribing paper sheet in association with the resistance value to heating means. CONSTITUTION:A sensitive body drum 2 is disposed at the center of a copying machine 1. A charger 3 for electrification, a developing unit 4, a charger 5 for transcription, chargers 6, 7 for separation and removal of electricity and a cleaning unit 7 are disposed around the sensitive body drum 2 to construct main image creating means and transcribing means. When a transcribing paper sheet passing through a paper sheet teed roller 16 or 17 is guided to transcribing means below the sensitive body drum 2, it is guided along a guide plate 8-1 to pass through a resistance sensor 32. Feeding of the transcribed paper sheet is interrupted temporarily there by a timing roller 39 to cause an electrode plate to be held in abutment against the back of the transcribing paper sheet so that its resistance is measured. When the resistance value is larger than a prescribed value, humidifying pipes 33 are operated and when the resistance value is smaller than the prescribed value on the contrary, heating rollers 37 are operated for correcting a water content to a proper value.

Description

DETAILED DESCRIPTION OF THE INVENTION 3. Detailed Description of the Invention Field of Industrial Application The present invention relates to a dry type electronic copying apparatus, and particularly relates to an improvement in a conveyance path for conveying transfer paper.

2. Description of the Related Art An electrostatic latent image holder, for example, an image forming means for creating a toner image using powdered toner on a photoreceptor, and a transfer system that rolls transfer paper into contact with the electrostatic latent image holder to obtain a toner image on the transfer paper. A fixing means for fixing the transferred toner image to the transfer paper using a member such as a heated roll, and a paper feeding means for supplying the transfer paper to the image forming means. In an electronic copying device that visualizes an electrostatic latent image formed on a latent image holder, a transfer paper is brought into contact with the electrostatic latent image holder to obtain a transferred toner image, and then heated. Since it is heated by the fixing means, the moisture contained therein evaporates, resulting in a decrease in the moisture content.

Generally, the paper used for transfer paper is JISP 8
Under the moisture measurement conditions of No. 111, about 4% to 8% moisture was contained, and the desired properties of the transfer paper were maintained.

However, as mentioned above, it is usually 160°C to 1°C.
When the transfer paper passes through a heat fixing means that is heated to about 90 degrees Celsius, the moisture evaporates due to the temperature, and the temperature of the transfer paper is approximately 2
The moisture content decreases by about 4% to 4%. As a result, physical distortion remains in the transfer paper, and the transfer paper is deformed due to shrinkage of the wood fibers that make up the transfer paper, and furthermore, the electrical resistance of the transfer paper increases due to a decrease in moisture content. This is the general tendency. Recently, in electronic copying devices, in order to save paper resources, it is possible to copy on both sides of transfer paper, or to make copies on one side two or three times in order to color the copy. As a result, during double-sided copying or single-sided copying multiple times, the electrical resistance increases and the deformed transfer paper is fed to the image forming means of the electronic copying device. In this type of paper feeding, the deformed transfer paper is fed to the conveyance path of the transfer paper in the image forming means of the electronic copying device, so the transfer paper comes into contact with a part of the conveyance path, causing a jam. Paper wrinkles are likely to occur because the paper is passed through the heat fixing means again in a deformed state. Furthermore,.

Because the electrical resistance of the transfer paper has increased, it is difficult for the charge on the transfer paper to escape, and as a result, the transfer papers stick together due to electrostatic attraction, leading to double feeding, or the toner image is distorted due to electrostatic effects. It's causing some disturbance.

On the other hand, recently, electronic copying devices are rarely used in places with a controlled atmosphere, and in the case of personal use, the humidity in the usage environment reaches 85 to 90%. is also occurring. In such an atmosphere, the transfer paper absorbs moisture and its moisture content reaches over 10%, resulting in paper jams in the transfer paper conveyance path due to a decrease in the stiffness of the transfer paper, and transfer defects due to a decrease in resistance. is inviting.

For example, in response to the above problems,
No. 58-125074 discloses an attempt to dehumidify the transfer paper and improve some of the above problems, but it cannot be said to be sufficient for correcting the characteristics of the transfer paper.

In addition, the inventors of the present application added a humidifying means to replenish the moisture content of the transfer paper that has passed through the fixing means, and attempted to improve the problem associated with the above-mentioned decrease in moisture content, but the use environment of electronic copying devices When the transfer paper is at a high temperature, the moisture content of the initially fed transfer paper is high, so if the humidification unit humidifies the transfer paper that has passed through the fixing unit, the moisture content will be excessive and the transfer paper resistance value will increase. Transfer defects occur due to a decrease in transfer paper stiffness, and paper jams, paper wrinkles, etc. occur due to a decrease in transfer paper stiffness, which often results in adverse effects.

Problems to be Solved by the Invention In such conventional transfer paper moisture content correction means, since the transfer paper whose moisture content is not regulated is fed to the image forming means or transfer means, the transfer paper's moisture content is not regulated. Resistance value,
Stable transfer, whose stiffness etc. vary depending on the environment in which the copying machine is used,
Paper transportation was difficult.

The present invention has been made in view of the above, and corrects the water content so that the resistance value of the transfer paper becomes an appropriate value, thereby correcting the deformation of the transfer paper, thereby preventing transfer defects and paper jams. The purpose is to prevent the appearance of wrinkles and wrinkles.

Means for Solving the Problems In order to solve the above problems, the present invention provides means for measuring the resistance value of the transfer paper in the paper feeding means and dehumidifying and humidifying the transfer paper in conjunction with the resistance value. By adding means to the transfer paper, an appropriate amount of moisture is added to the transfer paper to correct the characteristics of the transfer paper, and the paper is fed to the next image forming means.

Operation The present invention uses the above-described configuration to correct the moisture content of the transfer paper using the moisture content correction means controlled for the transfer paper, and corrects the deformation and electrical resistance of the transfer paper. This greatly reduces the incidence of transfer defects, paper jams, creases, and double feedings during normal copying, double-sided copying, and multiple single-sided copies.

Embodiment Hereinafter, an embodiment of the electronic copying apparatus of the present invention will be described with reference to the drawings.

FIG. 1 is an internal structural diagram showing an example of an electronic copying apparatus according to the present invention. In the figure, reference numeral 1 denotes a main body of a copying apparatus, and a photosensitive drum 2 is provided approximately in the center thereof so as to be driven to rotate in the direction of the arrow. Around drum 2,
Charging charger 3, developing device 41, transfer charger 5
, a charger for separating static electricity 6, and a cleaning device 7 are sequentially arranged in the rotational direction of the drum 2 shown by the arrow h,
It constitutes the main image forming means and transfer means of the image forming section.

To be more specific, this image forming section cleans the photosensitive drum 2 with a cleaning device 7, charges it with a charging charger 3, and transfers the charged surface of the photosensitive drum 2 through a scanning optical system 9 to a document placed on the upper surface of the main body 1. The image of the original placed on the placing glass 8 is exposed to light.1. An image forming means that forms an electrostatic latent image and develops this electrostatic latent image with toner using a developing device 4, and transfers the developed toner image onto a transfer paper that is sent in synchronization with the toner image. The main part is constituted by a transfer means for transferring by the charger 5. Furthermore, the transfer paper onto which the toner has been transferred is separated from the surface of the drum 2 by a charger 6 for separating and eliminating electricity. After the residual toner is scraped off by the cleaning device 7, the surface of the drum 2 from which the transfer paper has been separated returns to its initial state.

Reference numeral 10 denotes a document cover, which is attached to the main body 1 so that it can be opened and closed with respect to the document placement glass 8. 11 is an imaging lens of the scanning optical system.

On the left side of the image forming section is a paper feeding means for feeding the transfer paper to the transfer means, and on the right side of the image forming section is a drum 2 after the transfer.
A conveying path 12 for transporting the transfer paper separated from the transfer paper, a fixing means 13 composed of members such as a heating roll for fixing the transferred toner image on the transfer paper, and a paper discharge section for discharging the transfer paper after passing through the fixing means 13. are arranged to constitute a conventional copying machine.

The paper feeding means includes a paper feeding cassette 14 and a paper feeding cassette 15 for storing copy sheets of different sizes, which are mounted on the top and bottom of the copying apparatus main body 1 so as to project toward one side, and a paper feeding roller 16. By selectively driving the paper feed cassettes 14 and 17 and the temporary stop adjustment roller 28,
Alternatively, the transfer paper is sent from the conveyance path 19 to the first timing roller 39 and the second timing roller 20, and is synchronized with the movement of the toner image on the drum 2 to the transfer means below the photosensitive drum 2. and send it in.

The transfer paper discharged from the fixing means 13 is transferred to the paper discharge section by a paper discharge roller 21 . A guide claw 23 and a feed roller 24 are provided to feed the paper through the paper to the discharge tray 22. In the case of normal one-sided copying, transfer sheets are stacked and stored in the paper ejection tray 22 by the operation of these paper ejection sections.

The above-mentioned copying device has a
A single-sided copying aid that enables multiple copies to be copied again on the same side that has been copied, and a double-sided copying unit that sends the transfer paper after single-sided copying to the image forming section with its front and back reversed, and copies it on the back side. Auxiliary means are provided.

The selection of these two auxiliary means is based on the guide claw 23 and
The selection is made by the operation of the two guide claws of the guide claw 25. In the illustrated state of the guide pawl 23 in FIG. 1, these two auxiliary means are in operation, and furthermore, the guide pawl 25 and the double-sided copying auxiliary means are in operation.

The single-sided copying auxiliary means is formed by a guide claw 25 rotating clockwise, and the transfer paper that has passed through the fixing means 13 is guided by the guide claw 23 and the guide claw 25 and sent to the conveyance path 19. , feed roll 26, and
It is conveyed by a conveyor belt 27 and placed in a waiting state by a temporary stop correct adjustment roller 28 for the next copy. Then, it is sent to the first swimming roller 39 in accordance with the operation of the image forming section. The double-sided copy assisting means is a guide claw 23 shown in FIG.
, and is in an operating state in the state of the guide claw 25,
The transfer paper that has passed through the fixing means 13 is moved by the guide claw 23. The paper is stabilized by the guide claw 25 and once sent to the switchback section 30 by the feed roll 29, immediately sent back onto the conveyor belt 27 by the operation of the feed roll 29, and then temporarily stopped for copying the back side. Adjustment roller 28
is placed in a waiting state.

The transfer sheets that have undergone single-sided copying are stacked on the conveyor belt 27, as shown in FIG. 2, with the leading edges of the sheets being shifted backward by several centimeters.

The above is an example of a copying apparatus used under the present invention. The copying apparatus according to the present invention further includes the following configuration.

That is, in FIG. 1, the paper feed roller 16 or 17
When the transfer paper that has passed through is guided to the transfer means below the photoreceptor drum 2, it is guided along the guide plate 18-1,
The transfer paper passes through a resistance detection section 32 for measuring the electrical resistance value of the transfer paper. Here, the feeding of the transfer paper is temporarily stopped by the first timing roller 39, and the electrode plate 34 shown in FIG. 3 is brought into contact with the back surface of the transfer paper 43 to measure the resistance of the transfer M143. As shown in FIG. 4, the electrode plate 34 has three electrodes arranged concentrically, and insulating plates (Teflon plates) 35 are inserted between the electrodes and arranged alternately. This electrode plate 34 is connected to an AC current generator shown in FIG. 5 and a logarithmic amplifier described later to measure the surface resistance value of the transfer paper 43. The opposite side of the transfer paper to which the electrode plate comes into contact in the resistance detection section is a silicone rubber plate 3 that protrudes from a hole temporarily provided as a guide.
6 to increase the adhesion between the electrode plate and the transfer paper. In general, the relationship between the moisture content of transfer paper and the resistance value changes numerically depending on the moisture content, and the approximate value varies depending on the type of transfer paper, but as shown in Figure 6, it changes significantly depending on the moisture content. It is something. Therefore, a logarithmic amplifier is added to the resistance detecting section 32 to detect the voltage between the electrode plates which changes greatly, and a moisture content correction means is added to the resistance detecting section 32 by comparing the magnitude of the resistance value of the transfer paper with the desired resistance value. The control signal is sent to the That is, when the resistance value of the transfer paper is larger than the value when it is left under the moisture measurement conditions of JIS P8111, the humidifying pipe 33 in the moisture content correction means is used to increase the moisture content.
is activated, and conversely, when the resistance value is small, the heat roll 37 is activated to reduce the moisture content, so that when the transfer paper passes from the resistance detection section 32 to the moisture content correction means, the transfer paper is The moisture content of paper is corrected to an appropriate value.

The transfer paper that has passed through the resistance detection section 32 and the moisture content correction means is guided to the next process through the second timing roller 20. Note that the resistance detecting section 32, the humidifying tube 33, and the heat roll 37 are close to each other, and the moisture generated from the humidifying tube 33 and the heat roll 37 causes the resistance detecting section 32 to
The humidifying tube 33 and the heat roll 3 are used to prevent measurement fluctuations.
7 is covered with a box 38, and a first timing roller 39 is provided at the portion into which the transfer paper enters, to prevent high humidity air from diffusing into the resistance detection section 32. A hole is provided in one side of the box 38, and the highly humid air generated when the humidifying tube 38 and heat roll 37 are operated is discharged to the outside of the machine by a fan 40. FIG. 7 is an enlarged view of the main part of the water content correction means. In FIG. 7, one of the heat rolls 37 is made of Teflon resin at 0°4.
A rod-shaped halogen lamp is inserted into the center of an 11m thick aluminum pipe with a diameter of 25mm and the surface is coated with a thickness of about 1mm.
It consists of back-up rolls with a diameter of 25mm coated with 5mm thick silicone rubber, and as shown in the figure, two pairs of these rolls are arranged upside down. And each linear pressure is about 100 g per cm of nip part,
This value is much lower than that of a heat roll type fixing means which normally has a similar structure. Two halogen lamps with a power consumption of 300 W each are used, and the resistance value of the transfer paper is adjusted according to the JIS standard by the signal from the logarithmic amplifier.
It lights up when the resistance value is lower than that when left under the moisture measurement conditions of P.8111 to heat the aluminum pipe and dehumidify the transfer paper. The power applied to the halogen lamp is changed by the signal of the logarithmic amplifier and the normal commercial current is changed by the phase control of Cyrisk, and the power is removed from the transfer paper. ! It controls the amount of IT. FIG. 8 shows the humidifying tube 33.

FIG. 9 shows a humidifying means including a humidifying tube 33. In these figures, a plurality of small holes 41 are provided on the surface of the humidifying tube 33 through which the transfer paper passes. Two humidifying tubes 33 each having a small hole 41 are arranged side by side with the surfaces provided with the small hole 41 facing each other, and a temporary guide 1 is placed between them.
8-3 and the portion of the guide where the small hole 41 is provided is formed in a mesh shape to allow ventilation. A pipe 44 is connected to the humidifying pipe 33 so that humidified air is sent from a humidifying container 43 containing a humidity adjusting liquid 42 . A pipe 46 is connected to the humidifying container 43 so that air is sent from a pump 45. The electric motor that drives the pump 45 is an electric motor whose rotational speed is variable, and the rotational speed is changed in accordance with the signal from the logarithmic amplifier L7. Rotation starts when the resistance value is greater than the resistance value when the transfer paper is left under the JIS P 8111 moisture measurement conditions, and as the value increases, the rotation speed increases and the amount of air sent from the pump 45 increases. .

Since the water content correction means has the above configuration,
Approximately 15 to 20 seconds are required from detecting the resistance value of the transfer paper until the normal operating state is reached. During this time, the transfer paper is moved to the first timing roller 39 at the position of the resistance detection section.
It will be placed on standby.

However, when copying continuously, the fluctuation range of the resistance value of the first sheet of transfer paper and the resistance value of the second and subsequent sheets is small, so if this fluctuation range is within a certain value, the above resistance value Each timing roller is controlled so that the transfer paper is conveyed with the waiting time in the detection section being zero.

The electronic copying apparatus according to the present invention has the configuration described above. Using this copying apparatus, the following experiments were conducted to confirm the effects of the present invention. In other words, the copying device is capable of passing A4 size transfer paper in a horizontally fed state through a transfer means, a fixing means, and a paper feeding means. Double-sided copying was performed in an environment with humidity of 30%. The water content correction means uses humidified air with a transfer paper resistivity of 1015 Ωcm and a humidity of 90% for 15 minutes.
1/min, 7/min at 10'2ΩC@, 0 at 1011ΩC
It was installed so that it was sent to the humidifying pipe 33 at a rate of 17 minutes. (2) Electric power was applied to the heat roll 37 when the temperature reached 01°ΩcITl.

The applied power at this time was 150 W, and when it reached 10 qΩcm, 300 W was applied. Next, JISP
Moisture content 'M 79A under the moisture measurement conditions of 8111
, the direction of the fiber grain is perpendicular to the longitudinal direction of the transfer paper, and the basis weight is 6.
2g, resistivity 10 days A4 size transfer paper with Ω mark, horizontally fed 3
0 consecutive single-sided copies were made. At this time, the transfer sheets after single-sided copying were stacked on the conveyor belt 27 by the guide claws 23 and 25 so that the back-side copying was performed. Next, perform a continuous copying operation for 30 sheets on the back side of the transfer paper,
The copied transfer sheets were stacked on the paper discharge tray 22 by the guide claws 23. This operation was repeated 20 times to make a total of 600 double-sided copies. At this time, for comparison, copying was first performed without operating the water content correction means. As a result, in an environment of 30°C30%, the timing roller 2
0 or 15 jams occurred near the transfer charger 5. Furthermore, when the transfer paper is conveyed from the conveyance belt 27 to the timing roller 20, multiple sheets of transfer paper are simultaneously conveyed to the image forming section, which is called double feeding.
It happened again. Furthermore, some of the transfer papers stacked on the paper discharge toilet after double-sided copying had wrinkles in the direction of the fibers, and the number of such wrinkles was 191. The moisture content of the transfer paper under this environment is 6.4 before copying.
2%, and 3.10% after double-sided copying. on the other hand,
In an environment of 30° C. and 80%, paper jamming occurred only 2 times, double feeding occurred 4 times, and paper wrinkled only 0 sheets, which were significantly lower than in an environment of 30% humidity. However, in almost all the copies after single-sided copying, there were thin areas where the image was not transferred properly. The moisture content of the transfer paper in this environment was 11.5% before copying and 5.73% after double-sided copying. Next, the water content correction means was operated to control the water content of the transfer paper.

Then, a copying experiment similar to that described above was conducted. As a result, 8
In a 0% environment, paper jams occur 0 times, double feeds occur 0 times, and paper wrinkles occur 0 times.Compared to the case where the moisture content correction means is not operated, paper jams and double feeds do not occur at all. No particular defects such as poor transfer were observed on the image. In addition, even in an environment of 30% humidity, the occurrence rate was significantly reduced, with 1 paper jam, 0 double feeds, and 0 sheets with wrinkles. At this time, the transfer paper, which had a moisture content of 7% under the original JIS P8111 moisture measurement conditions, had a moisture content of 11.4% in an 80% environment, but by passing through the heat roll 37, It decreased to 8.20%. On the other hand, in an environment of 30% humidity, the moisture content was 6.50%, but by passing between the humidifying tubes 33, the moisture content increased to 8.30%. In addition, to measure the moisture content of the transfer paper, we used Microwave Nishi Paper Moisture Meter MX-2000 (Infrared
Engineering: I) was used.

Effects of the Invention According to the present invention, it is possible to significantly reduce malfunctions caused by transfer paper, such as paper jams, double feeds, paper jams, and transfer defects, which occur with ordinary electrophotographic copying means. The reason for this is that the moisture content of the transfer paper varies depending on the environment in which the copying machine is installed, and the deformation of the paper that occurs due to the forcible removal of moisture from the transfer paper by the heat fixing means. Alternatively, the effect can be improved by adjusting the physical properties of paper by correcting the water content to an appropriate value based on the resistance change before the paper is fed to the copying means. It is a symbol of industrial value.

[Brief explanation of the drawing]

Fig. 1 is an internal structure diagram showing an example of an electronic copying device according to the present invention, Fig. 2 is an enlarged view of the conveyor belt portion, Fig. 3 is an enlarged view of the main part of the resistance detection section, and Fig. 4 is an enlarged view of the electrode plate. 5 is a block diagram of the circuit of the resistance detection section, FIG. 6 is a graph showing the relationship between the moisture content of the transfer paper and the resistance value, and FIG. 7 is an enlarged view of the main parts of the guide plate and humidifying tube. FIG. 8 is an enlarged view of the humidifying tube, and FIG. 9 is a conceptual diagram showing the humidifying means including the humidifying tube. 2...Photosensitive drum, 5...Transfer charger, 12.19...Paper conveyance path, 13...
...Heat fixing device, 23.25...Guide claw, 30...Switchback section, 32...
・Resistance detection section, 33... Humidifying tube, 37...
・Heat roll. Name of agent Benkeshi Toshio Nakao and 1 other person Figure 2 Shu-Shusharetsu, Figure 6 Number Wei 7 (%) 7F! -/-1 Kaido I-2-ri 4 Kuu Huan 8th figure-Shasha training liquid 3-a 4 45--Gamasifu. Figure 9

Claims (1)

[Claims] An image forming means for creating a toner image on an electrostatic latent image holder, a transfer means for rolling a transfer paper into contact with the electrostatic latent image holder to obtain a toner image on the transfer paper, and a heated member. An electronic copying apparatus comprising at least a fixing means for fixing a transferred toner image on a transfer paper by a fixing means, and a paper feeding means for conveying the transfer paper to the image forming means, the electronic copying apparatus comprising: What is claimed is: 1. An electronic copying apparatus comprising: a resistance value measuring means; and a moisture content correcting means for humidifying and dehumidifying the transfer paper in conjunction with the resistance value obtained by the measuring means.