JPS59124350A - Both side recording method and its apparatus - Google Patents

Abstract

PURPOSE:To carry out both-side recording without causing wrinkles by transferring the first transferred image on an intermediate transfer body to the first side of a recording material, conveying this recording material, and bringing it again into contact with the intermediate transfer body to transfer the second transferred image on said body to the second side of the recording material. CONSTITUTION:An electrostatic latent image is formed on a photosensitive drum 9 by scanning an original 4 on an original platen 2 with light emitted from a light source, developed with a conductive magnetic toner 14, and the toner image is transferred and fixed to the first side of a transfer paper 24. The paper 24 is sent onto a receiving tray 28, turned upside down, again fed to a transfer and fixing section in the same direction as the time of the transfer and fixing of the first toner image to transfer and fix the second toner image onto the second side of the paper 24. Since the toner image on the intermediate transfer roll 1 and the paper 24 are heated with heaters 17, 19, respectively, before entering the transfer fixing section, heat deformation and wrinkling of the paper 24 liable to occur in such a case are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a double-sided recording method and apparatus.

Conventionally, in recording devices such as electrostatic recording and electrophotography, an electrostatic charge image is formed on an image carrier such as a photoreceptor drum, and this is developed using a developer mixed with toner and carrier as necessary. An image is formed based on a process in which the obtained toner image is transferred, for example, electrostatically onto copy paper and further fixed.

However, when a toner image is electrostatically transferred onto a copying paper (recording system) using a transfer electrode such as a corona discharger as in the past, charge disturbance occurs and the resolution of the toner image deteriorates. It will drop. Further, when a conductive magnetic or magnetic toner, which can produce a high-quality toner image with toner 12, is used, a state in which transfer is virtually impossible will result.

As a method to improve the above-mentioned drawbacks of electrostatic transfer, attempts have been made to suppress transfer onto copy paper using a suppressor roller, etc., but the transfer efficiency is poor and only about half of the toner image is transferred. Check if there are any problems, such as not being able to do so.

Therefore, for example, in Japanese Patent Publication No. 46-41679, Japanese Patent Publication No. 48-22763, Japanese Unexamined Patent Publication No. 49-78559, and US Pat. No. 3.993.825, intermediate transfer using rubber as a transfer layer is A method has been proposed in which the toner image is compressed and transferred onto a copying paper, and then the transferred toner image is heated and melted using a heat roller and fixed (transfer-fixed) onto a copying paper. In such a method, a toner image is suppressed and transferred onto the surface of a rubber-based transfer layer, such as silicone rubber or fluoro rubber, which has releasability on the one hand and has the property of adhering fine particles when pressed. The toner image on the transfer layer is heated and melted by contact with a heating body such as a heat roller, and is simultaneously pressed and transferred onto a fed copy paper and fixed. In other words, the toner image melted by heating is easily transferred and fixed onto the copy paper based on the above-mentioned releasability of the transfer layer, so there is no reduction in the resolution of the toner image due to the transfer process, and the transfer can be performed at a high transfer rate. It is said that this will be realized.

Incidentally, there are cases where it is necessary to form images on copy paper not only on one side but also on both sides. Although double-sided copying has already been carried out in known electrophotographic copying machines, the inventor's studies have revealed that the following defects exist. That is, in the suppressed heating type fixing method employed in known copying machines, the temperature in the fixing section is particularly high, so that the copy paper is deformed during fixing, and the copy paper is likely to wrinkle during double-sided copying. Moreover, since the fixing section is at a high temperature, the toner is fused to the roll of the fixing section, and the copy paper is likely to become wrapped.

As a result of further inspection and machining to address these problems, the inventor found that
By skillfully applying the intermediate transfer method described above,
The present invention has been achieved by discovering a recording method and device capable of double-sided recording without causing deformation, wrinkles, wrapping, etc.

That is, in the double-sided recording method according to the present invention, a toner iron formed on an image carrier such as a photosensitive drum is transferred onto an intermediate transfer member such as a roll or a belt, and this transferred toner image is transferred from the intermediate transfer member. When further transferring to a recording material (for example, copy paper), the first transferred toner image on the intermediate transfer body is transferred to the first surface of the recording material, and then the recording material is conveyed to a predetermined position. and then further conveying the recording material from this predetermined position to bring it into contact with the intermediate transfer body again, and transferring a second transferred toner image on the intermediate transfer body to a second surface of the recording material. It is characterized by:

According to the method of the present invention, since the toner image is transferred to the recording material by an intermediate transfer method using an intermediate transfer body,
Fundamentally different from the conventional pressure and heating type fixing method, the toner image and the recording paper can be preheated by a heating roll in the transfer/fixing section before fixing, which makes transfer (fixing) easier. It becomes possible to lower the temperature itself. Therefore, the recording paper is not deformed or wrinkled, the toner in the grooves is not fused, the recording material is not wrapped, and double-sided recording can be performed satisfactorily.

In the method of the present invention, it is particularly desirable to actively preheat the recording material before further transferring the transferred toner image onto the recording material. This is because the deformation of the recording material during transfer and fixing can be minimized, and the occurrence of wrinkles during double-sided recording can be minimized. However, in the case of copy paper, if the heating temperature is 160° C. or higher, it becomes easily deformed, so in order to prevent wrinkles, it is desirable that the heating temperature not be higher than 160° C.

The present invention also proposes an apparatus that can effectively carry out the above-mentioned double-sided recording method. That is, this device includes an image carrier such as a photosensitive drum, an intermediate transfer member such as a roll or belt that transfers the toner image on the image carrier, and a toner image formed on a part of the surface of the intermediate transfer member. a feeding means for feeding a recording material (for example, a copy paper) to a transfer section; and a feeding means for feeding a recording material (for example, a copy paper) to a transfer section, and a recording section on which a first transfer toner image on the intermediate transfer body is transferred onto a first surface of the recording medium at the transfer section. A holding part (for example, a paper feeding box) that temporarily holds the recording material, a refeeding means (for example, a paper feeding roller, etc.) that refeed the recording material from this holding part, and a recording material from this refeeding means. The double-sided recording apparatus is characterized in that it has a guide means for guiding the intermediate transfer member so that its second surface comes into contact with the intermediate transfer member at the transfer section. This apparatus is preferably provided with a heating means for preheating the recording material before the transfer section, and the preheating temperature is 16.
It is desirable that the heating means be controlled so that the temperature does not exceed 0°C.

Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings.

FIG. 1 shows the main parts of an example of a suppression transfer type double-sided copying type electrophotographic copying machine incorporating a roll-shaped intermediate transfer member 1. As shown in FIG.

In this copying machine, an original 4 covered with a platen cover 3 is placed on a glass original placing stand 2 on the upper wall of the main body, and light 6 from a light source 5 inside the main body is irradiated onto the original. The reflected light passes through 8LA (self-lock lens array) 7, is reflected by mirror 8, and then enters onto photoreceptor laminate 9. Therefore, the photosensitive layer 10 made of selenium, an organic photoconductive material, etc. of the drum 9 is subjected to imagewise exposure in a pattern corresponding to the original image, thereby forming an electrostatic latent image.

Reference numeral 11 in the figure is a corona charger, which charges the entire surface of the photosensitive layer to a predetermined polarity in an unexposed state.

In addition, 12 is a light emitting diode array for preventing black frames, or
A device consisting of an electroluminescent plate or the like,
It has the function of eliminating the charge on the non-image area on the g-light body and preventing toner from adhering to the non-image area. A known conductive magnetic toner 14 is supplied from a developing sleeve 13 to the photosensitive drum 9 on which the electrostatic latent image is formed. The toner 4 is conveyed on the sleeve 13 while its thickness is regulated by a magnetic roll 15 for regulating the toner thickness, and its conveying force is exerted by the rotation of the sleeve 130 and the rotation of the magnet roll 16 inside the sleeve 13. Ru. and,
Since a reverse charge is induced in the toner 14 by the electrostatic latent image on the photoreceptor drum 9, the toner particles are sequentially moved and adsorbed onto the photoreceptor drum 9 in proportion to the amount of charge of the electrostatic latent image, and are attracted thereto. A toner image of a predetermined pattern is formed on the toner image, and development is performed.

Next, the toner image formed in this way is applied to the photoreceptor drum 9 under a linear pressure of about 0.5 kg/cTL or less (for example, about 0.1
The image is suppressed and transferred to the intermediate transfer roll 1 in contact with the pressure of kg/(yl). Since this roll 1 has a surface layer mainly composed of silicone rubber, it sufficiently peels off the toner particles on the photoreceptor drum 9. The peeled toner particles are preheated to a predetermined temperature (that is, a temperature that exhibits sufficient releasability) by a heater lamp 17 in the roll 1, and then transferred to the next pressure roll 18 on the intermediate transfer roll 1. carried to the position. The pressure roll 18 is heated to a predetermined temperature by an internal heater lamp 19, and the paper is fed by the paper feed roll 21 via a guide plate n to a conveyance roller holder, and from there the copy paper row is transferred. It is fed into the space between rolls 1 and 18 (transfer and fixing section) while being heated.

Therefore, the copy paper row has a temperature sufficient to transfer the toner image, and when it is fed between the rolls 1 and 8, the already preheated toner image is separated from or transferred from the roll 1, and at the same time Fusing of the toner image on copy paper 24 may also be performed. Note that 5 in the figure is the pressure roll 18.
26 is a cleaning roller for the intermediate transfer roll 1; 27 is a guide plate for sending the fixed copy paper to the paper discharge roller 29 on the fourth side of the tray; 30
numeral 31 is a guide plate for double-sided copying, and 31 is a guide plate for double-sided copying.

At the subsequent stage of the intermediate transfer roller 1, the photosensitive drum 9 is irradiated with light from a static elimination lamp 32 through a transparent filter 33 to erase residual charges on the drum. Furthermore,
A cleaning member 34 made of, for example, a fur brush is brought into contact with the photosensitive drum 9, and the remaining toner particles separated by this are collected on a collection magnet 36 by a scraping lever 35.

What should be noted in a copying machine configured as above is that
After the first toner image is first transferred and fixed from the intermediate transfer roll 1 to the first surface of the copy paper waste fed from the paper feed addition,
The receiver re-feeds the copy paper fed onto the blood path to the transfer and fixing section from the same direction as when transferring and fixing the first toner image while reversing the copy paper inside out, thereby effectively achieving double-sided copying. That's true. In other words, according to double-sided copying using this intermediate transfer method, the toner image on roll 1 and the copy paper are preheated by each heater 17, 19 before entering the transfer and fixing section, so that the transfer and fixing section itself The temperature can be much lower than in conventional fusing sections. As a result, thermal deformation and wrinkles that tend to occur in copy paper are eliminated, and high-quality double-sided copying is possible, as well as toner fusion at the transfer and fixing section and paper wrapping can be prevented. For this purpose, it is desirable that the heating temperature by each heater 17.19 be 160°C or less, for example 100°C to 140°C. Particularly preferred is around 120°C.

Since the device according to this example heats the intermediate transfer roll, toner, and copy paper together, it is possible to lower the heating temperature required for each of them, thereby eliminating the need to excessively heat each of them. In addition, the amount of heat dissipated can be suppressed to a small value, and the overall heat utilization rate can be greatly improved, and the total energy consumption can be significantly reduced.

Further, it becomes possible to transfer and fix toner images at high speed. In addition, since the intermediate transfer roll 1 is not heated excessively, even if the toner image carrier 9 has a basic property sensitive to heat, such as a photoconductive photoreceptor, its good properties can be maintained. or prevent inconveniences such as part of the material components of the intermediate transfer roll 1 adhering to the toner image carrier 9, and the intermediate transfer roll 1 is not exposed to changes in high temperature. This allows it to retain its durability over a long period of time,
Alternatively, the heat resistance conditions required for the material of the intermediate transfer roll 1 can be relaxed, the selection range of materials can be expanded, and costs can be reduced. Further, the toner is not heated excessively, and image blurring or offset phenomena due to excessive fluidity of the toner do not occur.

In addition, copy paper is not heated excessively, thermal deformation and wrinkles of the transfer material do not occur, and there is virtually no risk of fire.

FIG. 2 shows a double-sided copying machine according to a second embodiment of the present invention, and parts common to those in FIG. 1 are given common reference numerals and their explanations are omitted.

According to the example shown in FIG. 2, the copy paper fed from the paper feed box 20 is guided to the pressure roll 18 by the guide plate 4, and a preheating plate 37 disposed near the pressure roll 18
After being pre-heated to a sufficient temperature by When in the -1 single-sided copy mode, the copy sheet from the transfer and fixing section is sent from the guide plate 27 to the guide roller A and the paper ejection roller 29 to the paper ejection tray to the blood path. In the double-sided copying mode, copy paper is selectively guided from the guide plate 27 to a branched copy paper path 39, passes through a paper discharge roller 41, and is temporarily stored in a paper feed section 42 for holding copy paper. Ru. When in single-sided copying mode, the passage 39 for double-sided copying is closed as shown by the broken line in the drawing, and when in the double-sided copying mode, the passage 39 for single-sided copying is closed as shown by the dashed line in the drawing. For this purpose, for example, a rotary switching guide plate can be provided that can be selectively switched between the broken line position and the one-dot chain line position.

The copy paper stored in the paper feed section 42 is fed out to the guide plate 31 by moving the paper feed roller 40, which is movable back and forth between the solid line position and the dashed-dotted line, and then fed out to the guide plate 31 along the same path as for single-sided copying. The image is then sent to the transfer and fixing unit. At this point, the next toner image has already been transferred from the photoreceptor 9 side to the intermediate transfer roll 1, and this toner image is transferred and fixed onto the other side of the copy paper at the transfer and fixing section. During double-sided copying, the copy paper from the paper feed section 42 is reversed and sent to the transfer and fixing section.

In this example as well, for the same reason as mentioned above, it is desirable that the intermediate transfer roll 1, pressure roll 18, and preheating plate 37 not be heated to 160° C. or higher.

Note that as a cleaning means for the photoreceptor 9, a blade 44 is provided in place of the above-mentioned fur brush.

Different from the examples shown in FIGS. 1 and 2, FIG. 3 schematically depicts another embodiment using a belt-shaped intermediate transfer body, and is common to FIGS. 1 and 2. Common reference numerals are given to parts, and explanations are omitted.

In the figure, 51 is an electrostatic latent image forming section including the above-mentioned charger 11 and exposure system, 53 is a developing section including the above-mentioned developing sleeve 13, numeral 51 is a static eliminating section including the above-mentioned static eliminating lamp 32, etc., and 59 is the above-mentioned static image forming section. This is a cleaning section including a cleaning member 34 and the like. The intermediate transfer section includes a transfer roll 60 and a pressure roll 61.
, a transfer belt 71 that is run via a tension roller 62. The transfer belt 71 is made of a base material such as an electroformed nickel belt or a stretch-cast polyimide belt, on which a heat-resistant elastic layer and a surface layer (transfer layer) as described above are laminated. . The transfer belt 71 is pressed against the photoreceptor drum 9 to remove p) the toner image, and then the infrared heater 65
After being preheated, the toner image is brought into close contact with copy paper waste passed between it and the pressure roll 18, and the toner image is transferred and fixed onto the copy paper row. After this transfer, paper dust and the like on the belt 71 are removed by a cleaning device 64, and the transfer surface of the belt 71 is further neutralized by a static eliminator 66.

In this example as well, mechanisms for single-sided and double-sided copying modes are provided as in the case shown in FIG. 2, and copying in each mode can be selectively performed in the same manner as in the above-described example.

Although the present invention has been illustrated above, the embodiments described above can be further modified based on the technical idea of the present invention.

For example, the arrangement, structure, etc. of the mechanism implementing the above-described copy mode may be changed in various ways. Further, the object of the present invention can be achieved by heating only one of the intermediate transfer body and the pressure roll. Furthermore, other known mechanisms may be used as the intermediate transfer mechanism described above. Note that the method of the present invention can be applied to distribution devices other than electrophotographic copying machines.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which FIG. 1 is a sectional view of a main part of an electrophotographic copying machine having an intermediate transfer body, and FIG. 2 is a sectional view of a main part of an electrophotographic copying machine according to another example. , FIG. 3 is a schematic diagram of yet another example of an electrophotographic copying machine. In addition, in the symbols shown in the drawings, 1.71... Intermediate transfer body 9... Photosensitive drum 13... Development sleeve 14... ......Toner 17.19... Heater lamp 18.61...
...Crimping roll ribs...Paper feed box 21.40...Paper feed roller 22.27.31...Guide U...・・Copy paper ・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・・ “ “ “34 44 “ ” “” “” “” “”
... Paper preheating plate 39 ... Paper passage 42 for double-sided copying mode
......- Paper feed section (box) (a) ...... Transfer roll 62 ...... Tension roller 65...
・River...It is a heater. Agent: Patent attorney Hiroshi Aisaka (and 1 other person) (voluntary)
Proceedings by Ichi Masato 2, April 4, 1980, Mr. Kazuo Wakasugi, Commissioner of the Patent Office, Indication of the Case, 1982 Patent Application No. 232471 2, Method and Apparatus for Recording Names of Inventions on Both Sides 3, Amendments Relationship with the case involving the person who filed the patent application Patent applicant address: 1-26-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name:
(127) Roku Konishi Photo Industry Co., Ltd. 4, Agent 6, Number of inventions increased by amendment 7, Detailed explanation column of the invention in the specification subject to amendment, and Figures 1 and 2 of the drawings 8, Contents of amendment (1), "This..." on page 8, lines 31-19 of the specification.
·····It is formed. ” to “This copier has
A document 4 covered with a platen cover 3 is placed on the glass surface of a document table 2 movably installed on the upper wall of the main body, and light 6 is emitted from a light source 5 inside the main body to the document. , is irradiated through a slit 50 provided on the upper wall of the main body, and the reflected light passes through an SLA (self-hock lens array) 7.
After being reflected by the mirror 8, the light is incident on the photosensitive drum 9. Therefore, the uniformly charged photosensitive layer 10 made of selenium, organic photoconductive material, etc. on the drum 9 is exposed to image light in a pattern corresponding to the original image by moving the original table 2 in the direction of the arrow. An electrostatic latent image is formed. ” I am corrected. (2) "Mr. 1" on the third line from the bottom of page 15 is "Illustrated"
I'll start by correcting that. (3), 2nd to 1st lines from the bottom of page 9, “Approx. 0.5 kg/
cm or less (e.g. about 0.1 kg/cm) J [about 1
．． 0 kg weight/cm or less (e.g. approximately 0.4 kg weight/cm)
I'll correct it with J. (4) Of the drawings attached to the application, Figures 1 and 2
Correct the diagram as per the attached sheet. One or more -

Claims (1)

[Scope of Claims] 1. When a toner image formed on an image carrier is transferred onto an intermediate transfer member, and when this transferred toner image is further transferred from the intermediate transfer member to a recording material, After transferring the first transferred toner image to the first surface of the recording material, the recording material is conveyed to a predetermined position, and then the recording material is further conveyed from this predetermined position to the intermediate transfer body. A double-sided recording method characterized in that the second transferred toner image on the intermediate transfer member is transferred to the M2 side of the recording material. 2. The method according to claim 1, wherein the recording material is characterized before the transferred toner image is further transferred to the recording material. 3. The method described in claim 2, in which the recording material is not heated to 160° C. or higher. 4. an image carrier, an intermediate transfer member for transferring the toner image on the image carrier, and a feeding means for feeding the recording material to a transfer portion formed on a part of the surface of the intermediate transfer member; a holding section that temporarily holds the recording material on which the first transferred toner image on the intermediate transfer body has been transferred to the first surface in the transfer section;
re-feeding means for re-feeding the recording material from the holding section; What is claimed is: 1. A double-sided recording device comprising: a guide means for guiding the double-sided recording device; 5. The apparatus according to claim 4, further comprising heating means for preheating the recording material before the transfer portion formed on a portion of the surface of the intermediate transfer body. 6. The apparatus according to claim 5, wherein the heating means is controlled so that the preheating temperature of the recording material does not exceed 160°C.