JPH02306262A - Either side freely recording device - Google Patents

Abstract

PURPOSE:To perform copying with compact constitution without an inverting operation by transferring toner images on a photosensitive body and on a belt to a facing paper surface. CONSTITUTION:It is assumed that a monochromatic image is formed. An alternating current and a direct current (-) are impressed on a charger 115. Since a charger 131 previously performs a static eliminating action, the alternating current and the direct current (+) are superposed and impressed on a charger 129 in order to convert the polarity of a belt surface after static eliminating. The surface of a photosensitive drum 105 is uniformly electrostatically charged to be (-) in the dark by a main electro static charger 114 with the rotation of the drum 105. The surface of the drum is ex posed and scanned with scanning light L' and an image is carried on the drum surface as the latent image of a mirror image, which is made visible with red (-) toner by a developing device 106R. A primary toner image is transferred to the surface of a transfer sheet S by (+) corona discharging in a different polarity from the toner by a charger 108 to be fixed, then the transfer sheets are stacked. The belt 107 is cleaned by a cleaner 116 and the drum 105 passes a static eliminator 111 and cleaner 112 to prepare for next operation. Thus, copying can be performed flexibly in terms of surface with simple constitution without using an inverting means.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a surface-free recording device that can freely form images on the front and back sides of transfer paper, and more specifically relates to a laser printer, digital copying machine, etc. The present invention relates to a surface-adjustable recording device that can be applied to.

(Prior Art) (1) An electrophotographic copying machine that is equipped with one photoreceptor drum, forms a toner image on the photoreceptor drum, transfers the toner image to transfer paper, and then fixes and final stacks the image. Are known.

In this type of copying machine, the image surface of the final stacked transfer sheets is limited to the top if the transfer process is performed on top of the paper, and to the bottom if the transfer process is performed from below.

This causes inconveniences in terms of page alignment, especially when obtaining double-sided images, and it is not possible to meet the various needs of users.

For this reason, there are (1) examples in which a paper reversing means is provided in the conveyance path, and (2) examples in which two photoreceptor drums are provided facing each other and when the transfer paper is passed between these two drums. For example, Japanese Patent Application Laid-Open No. 57-63559, Japanese Utility Model Publication No. 58-
There are techniques such as No. 166650.

(Problem to be Solved by the Invention) Regarding the prior art (1) above, the reversing operation takes time, which is an obstacle to improving the so-called copy productivity, and in double-sided copying, the fixing unit is not used. Since the paper is passed twice, there are problems such as misalignment of the image, wrinkles, and folding of the paper due to the effects of heat shrinkage.

Regarding the prior art (2) above, it is possible to perform surface-uniform copying without using a reversing means, but since the photosensitive drums equipped with developing means etc. are constructed in pairs, the apparatus becomes larger and more complicated. However, there are practical problems.

SUMMARY OF THE INVENTION An object of the present invention is to provide a recording device that can freely form images on any surface with a simple and compact configuration without using a reversing means.
It is an object of the present invention to provide a surface-adjustable recording device that enables fixing on either back surface.

(Means for Solving the Problems) In order to achieve the above object, the surface flexible recording device of the present invention includes an optical writing means capable of writing an image on a writing target as a normal image or a mirror image, and a barrel rotatable photoreceptor; a developing means for visualizing the latent image written on the photoreceptor by the optical writing means as a primary toner image; and a transfer paper disposed opposite to the photoreceptor; A belt serving as an intermediate transfer member configured to freely pass paper; a primary toner image transfer means for transferring the primary toner image onto the transfer paper; and a secondary toner image transfer means for transferring the primary toner image to the belt. The apparatus is provided with an intermediate transfer means for transferring the image as an image, and a secondary toner image transfer means for transferring the secondary toner image onto the transfer paper.

Furthermore, it is effective to have the belt serving as the intermediate transfer body also serve as conveyance means for the transfer paper.

Furthermore, it is preferable that the fixing means for fixing the toner image on the transfer paper sent out from the belt serving as the intermediate transfer member is constituted by opposing rollers for one sheet, and each of these rollers is a heating roller.

(Function) A toner image is formed both or selectively on the photoreceptor and the belt as an intermediate transfer member, and the formed toner image is transferred onto the facing transfer paper surface.

Furthermore, irrespective of whether one single-sided image is formed or one double-sided image is formed, the fixing of the transfer paper is completed by passing the paper through the fixing unit once.

(Example) First, an example of a recording apparatus suitable for carrying out the present invention will be described with reference to FIG.

In FIG. 1, the recording apparatus is roughly divided into a document reading means, an optical writing means, an image forming means, a fixing means, a paper feeding means, and a transfer paper conveying means.

The document reading means includes a contact glass 100 on which the document G is placed. A pressure plate 127 that covers these, a lamp 101 for illuminating the original G, a first mirror M1 that moves in the scanning direction A integrally with this lamp 101, and this first mirror M
1, a group of mirrors M2 that moves in the scanning direction A in conjunction with the imaging lens 102, a color image sensor 103, and the like. Although not shown, an automatic document feeder is optionally included.

With this configuration, when the document G is scanned, the document image information is color-separated by the color image sensor 103, converted into a digital signal, and stored in a storage means (not shown).

Next, the optical writing means includes means for applying the original information stored in the storage means to a drive current of a semiconductor laser, a semiconductor laser, a rotating mirror 104 for deflecting and scanning the beam from the semiconductor laser, and an fθ lens. an imaging optical system 99 including a photoreceptor drum lO to be written with the beam;
It consists of a mirror M3 etc. for guiding the As the photoreceptor, one of OPC, Ss type or CdS type is used.

Since the optical writing means stores image information in the form of digital signals, it is also possible to write a normal image on the photosensitive drum 105 by changing the writing order.

Exporting a mirror image can also be arbitrarily selected and controlled.

Next, the image forming means includes a photoreceptor drum 105 that is rotated in the direction of the arrow, and a developing means 106 that visualizes the latent image written on the photoreceptor drum 105 by the optical writing means as a primary toner image. A belt 107 as an intermediate transfer member is placed opposite to the photoreceptor drum and is set to allow transfer paper to pass freely between the belts, and a belt 107 is placed on the back side of the belt 107 at a position opposite to the photoreceptor drum 105. It consists of a charger 108 that is immovably arranged toward the vehicle, and other incidental means. The material of the belt 107 is polyester film (50~
150 μm), a dielectric film such as vinylidene tetrafluoride film is used. Photosensitive drum 105 and belt 1
07, synchronous control is achieved by, for example, servo motor drive control, and care is taken to prevent image shift.

Regarding the above-mentioned other incidental means, regarding the area around the photoreceptor drum 105, they are arranged in the order of the rotational direction of the drum.

Pre-transfer band IE device 109. Static eliminator 110. Pre-cleaning static eliminator 111, cleaner 112. The static eliminator 113, the main charger 114, etc., and around the belt 107,
A charger 115 is arranged at the upper left end of the belt, a charger 131 is arranged near the downstream of the charger 115 in the belt rotation direction, a cleaner 116 is arranged at the lower right end of the belt, and a charger 116 is arranged downstream of the cleaner and upstream of the charger 108. charger 129 etc.

In the example shown in FIG. 1, the developing means 106 is configured to include two developing devices, a red developing device 106R for developing red toner and a developing device 106B for developing black toner. It is meant to be done.

In each developing device, the symbol OR indicates a developing roller.

On the other hand, when recording a full-color image, developing devices using cyan, magenta, and yellow toners are placed around the photoreceptor drum at predetermined developing positions, or as shown in FIG. ' is used. It consists of four developing units each housed in four partitioned areas within the rotating cylinder 130.

These four developing devices include a developing device 106'Y for developing yellow toner and a developing device 106'Y for developing magenta toner.
M, a developing device 106'C for developing cyan toner, and a developing device 106'B for developing black toner, each of which contains toner of each color.

In each of these developing units, the rotating cylinder 103 is rotated so that the developing unit containing toner of the color to be visualized faces the photosensitive drum 105 in accordance with the arrival of the latent image of the color to be visualized.
The developing roller GR of the developing device stops at a position facing the photosensitive drum 105, and development is performed.

Returning to FIG. 1, the cleaner 116 is centered at one end fulcrum J.
It is rotatable, and is moved toward and away from the belt depending on whether cleaning of the belt is necessary or not.

Next, the fusing means is indicated by the reference numeral 117. This is composed of opposing rollers 117A and 117B for paper passing using Si rubber rollers etc. arranged close to the downstream of the belt 107, and has the function of heating and fixing the unfixed toner image on the transfer paper sent out from the belt. ing.

Next, the paper feeding means is a cassette paper feeding section 118, 119. which holds the transfer paper S in a stacked manner. Separation feeding roller 12o.

121, a registration roller 122, etc.

Next, the transfer paper conveying means includes a paper guide SG leading from the fixing means 117 to the stacking section 123, a pair of feed rollers R, a path switching pawl 124 provided at the intermediate portion of the paper guide, and a path switching pawl 124 that branches out. It consists of a paper guide SG' that guides the paper to the registration rollers 122, an intermediate stack section 125, a recycled paper feeding roller 126, a paper guide SG' that connects the rollers and the registration rollers 122, and the like.Furthermore, in this example, the belt 107 itself Since it is installed in such a manner that it connects the registration roller 122 and the fixing means 117, it can be said that it also serves as a transfer paper conveyance means.

Two modes are available for transporting the transfer paper S. One of them is from the cassette paper feed section 118° 119 to the registration roller 122, the belt 107, and the fixing means 1'17.
This is a one-pass mode in which the sheet is sent to the stack section 123 via the path switching claw 124 which is rotatably positioned in the position shown by the imaginary line. The other one is the cassette paper feed section 118.1
19, the registration roller 122, the belt 107, the fixing means 117, and the path switching claw 1 rotated to the position shown by the solid line.
24 to the intermediate stacking section 125, and then being sent out again to the registration rollers 122 by the feeding roller 126, passing through the fixing means 117, and reaching the stacking section 123. This is a recycling mode.

Each of these modes can be selected arbitrarily.

Next, methods for forming various images will be explained.

The apparatus configuration is basically the same as that shown in FIGS. 1 and 2, but there are some differences depending on the image forming example. The different parts will be explained in the following explanations.

Example 1 This example is characterized by the processes shown in FIGS. 3 to 8.

In this example, the following image formation methods 1 to 5 are possible.

Method King (see Figures 1 and 3).

(Mode) This method forms a monochrome image on the surface of the transfer paper.
Performed in monochromatic, single-sided mode.

Selection of this mode is performed by operating a selection button switch on the operation section, and is executed by a control means using a CPU.

In FIG. 3, alternating current and direct current (-) are applied to the charger 115 in order to separate the transfer paper from the belt. However, it does not work in this mode.

In addition, since the charger 131 performs static elimination in advance in preparation for changing the polarity of the belt surface, the charger 129 applies alternating current and direct current (+) in a superimposed manner to change the polarity of the belt surface after static elimination. There is. However, it does not work in this mode.

(Process) As the photoreceptor drum 105 rotates, the main charger 114 uniformly charges the photoreceptor drum 105 (-) in the dark.

Next, the surface of the photosensitive drum is exposed and scanned by the scanning light L' from the optical writing means so that the charge on the image area is erased.

In order to make the image on the transfer paper surface a normal image, the scanning by the scanning light L'' is controlled so that the latent image is carried on the photoreceptor drum surface as a mirror image.

Next, this latent image is visualized as a primary toner image using red (-) toner in the developing device 106R.

Note that when it is desired to obtain a two-black image, the toner is developed using the developing device 106B. In FIG. 6, a polarity symbol surrounded by a circle indicates toner charged to that polarity. The same shall apply hereinafter.

The leading edge of this primary toner image meets the leading edge of the transfer paper S fed out from the registration rollers 122 in a timely manner at the charger 108 section. And charger 1
A primary toner image is transferred onto the surface of the transfer paper S by a (+) corona discharge having a polarity different from that of the toner caused by No. 08. Therefore, in this example, charger 108 is a primary toner image transfer means. Transfer paper S with a primary toner image formed on one surface in this way
is separated from the belt, passes through the fixing means 117, and is stacked in the stacking section 123 with the image side facing up.

After the transfer paper has been separated, the belt surface is cleaned by a cleaner 116 and prepared for the next process. The cleaner 116 is used because toner may remain on the belt depending on the size of the transfer paper.

On the other hand, after the transfer, the surface of the photosensitive drum 105 is neutralized by a pre-cleaning static eliminator 111, residual toner is removed by a cleaner 112, and further static electricity is removed by a static eliminator 113 in preparation for the next process.

(Method Advantages) Since the transfer process only needs to be performed once, copies can be made without any damage to images, similar to conventional black-and-white copying machines.

Method 2 (see Figures 1, 4, and 5).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

In this method, alternating current and direct current (+) are applied to charger 129 during the process. In addition, charger 115, 1
29.131 is in the functional state. The rest conforms to the contents explained in Method 1.

(Process) Referring to FIG. 4, according to method 1, the photoreceptor drum 10
5 is uniformly charged (-).

Next, the surface of the photoreceptor drum is exposed and scanned so that the charge on the image area is erased by the scanning light from the optical writing means.

In order to make the image on the transfer sheet a normal image, the scanning by the scanning light is controlled to be written so that the latent image of the normal image is carried on the surface of the photoreceptor drum.

Next, this latent image is visualized as a primary toner image using red (-) toner in the developing device 106R. Note that when it is desired to obtain an illuminated image, development is performed using the developing device 106B.

This primary toner image is transferred to the surface of the belt 107 as a mirror secondary toner image by a (+) corona discharge having a polarity different from that of the toner from the charger 108 .

Therefore, in one example, the charger 108 functions as an intermediate transfer means for transferring the primary toner image to the belt as a secondary toner image.

Next, as shown in FIG. 5, the belt 107 carrying this secondary 1-toner image is neutralized together with the secondary toner image by a charger 131 in order to change the polarity.

The cleaner 11 is separated from the belt surface in advance.
After passing through the 6th part, the polarity is changed to (+) by corona discharge from the charger 129.

This secondary toner image whose polarity has been changed to (+) is applied to the back surface of the transfer paper S fed at the same timing by (+) corona discharge from the charger 108.

transcribed.

Therefore, in this example, the charger 108 also functions as a secondary toner image transfer means for transferring the secondary toner image onto the transfer paper. In this way, the transfer paper S with the secondary toner image formed on the back side is transferred to the belt 10 by the function of the charger 115.
7 and is separated from the stack unit 12 through the fixing means 117.
3 is stacked with the image side facing down. Note that in the above description, the charger 115 also has a function of eliminating static electricity from the belt.

(Advantages of methods 1 and 2) By switching between the modes related to methods 1 and 2 using the switching means, it is possible to form an image on either the front or back side of the transfer paper. When copying one copy from a copy, there is no need to align the pages of the copy, which is very convenient.

Additionally, some users may not want their copies to be seen by others, so they may request that they be ejected into the stack section with the image side facing down, or vice versa, they may want to immediately check the quality of the copies. Therefore, there are cases where it is required to discharge the paper to the stack unit with the image side facing up, and it is possible to meet these demands.

Furthermore, in conventional monochrome copying machines, a separate device for separating the photoconductor and transfer paper, and a separate paper conveyance device after separation are required, but in this example, the belt as an intermediate transfer body also serves as a conveyance means for the transfer paper. Furthermore, since curvature separation is performed, paper conveyance is highly reliable, and copying productivity can be increased by increasing the copying speed.

Method 3 (see Figures 1, 4, and 6).

(Mode) This method is a method of simultaneously forming monochrome images on both sides of the transfer paper, and is carried out in monochrome duplex mode.

This mote selection is also performed in accordance with method 1 above.

The manner of voltage application to each charger is in accordance with Method 2.

(Process) First, a secondary toner image is formed on the belt 107 according to method 2 (see FIG. 4). At this stage, charger 129
．． 131 works. Next, according to Method 1, a primary toner image is formed on the photoreceptor drum.

Then, as shown in FIG. 6, the primary toner image and the secondary toner image are simultaneously transferred to the front surface of the transfer paper S and the secondary toner image to the back surface, respectively, and sent to the fixing means 771.

(Advantages of Method 3) Since double-sided copies can be obtained without using reversing means, the configuration is simplified and copy productivity is improved.

Method 4 (see Figures 1, 2, 4, 7, and 8).

(Mode) This method is a method of forming a two-color image of black and red or a full-color image on the back side of transfer paper, and is performed in color single-sided mode.

This mode selection is also performed in accordance with method 1 above.

Developing units 106B, 106R and charger 115.1
29°131 is in the functional state. In particular, the charger 108 is provided with a function of making the transfer voltage variable.

(Process) According to the explanation in FIG. 4 in method 2, a red secondary toner image is transferred onto the belt 107, and a black latent image is further carried on the photoreceptor drum. and.

As shown with diagonal lines in FIG. 7, a black toner image is visualized by the developing device 106B, and the already formed belt 1
The charger 108 compositely transfers the red toner image onto the red secondary toner image on the red toner image 07. At that time, the transfer voltage is increased sequentially for the second secondary toner image transfer compared to the first secondary toner image transfer.
The charger 131 eliminates charges from the belt and toner to maintain transfer efficiency.

As shown in FIG.
The image is transferred to the back side of the transfer paper S, separated from the belt by the charger 115 and discharged from the belt, and sent to the fixing means 117.

In addition, in the above, the charger 129 is
It operates in the process immediately before the retransfer of the secondary toner image of the color mirror image, and the polarity of the secondary toner image sequentially synthesized on the belt and the belt is switched just before the transfer paper is overlapped.

Although the above explanation deals with the formation of a two-color image, in the case of forming a full-color image, the developing means 106 is replaced by a second
A developing means 106'' shown in the figure is used.

(Advantages of method 4) Formation of a single-sided color image becomes possible with a simple configuration.

Method 5 This method is a method of forming a single-color image on the front side and a two-color or full-color image on the back side. After forming a color secondary toner image on the belt through a process similar to method 4 above, the image is transferred onto the photoreceptor drum. forming a monochromatic primary toner image and performing method 3 as described above;
A monochrome image is transferred to the front side of the transfer paper and a color image is transferred to the back side using a process similar to that of .

Example 2 This example is characterized by the processes shown in FIGS. 9 to 12.

In this example, the following image formation methods 6 to 11 are possible.

Method 6 (Mode) This method is a method of forming a monochrome image on the surface of transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

Charger 131 does not function. The polarity of the charger 108 can be switched. charger 129
functions as a static eliminator for the belt and applies alternating current superimposed on direct current.

(Process) The charger 108 is switched to receive (+) corona discharge, and a monochromatic image of (-) toner is formed on the surface of the transfer paper according to Method 1.

Method 7 (see Figures 9 and 10).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

The charger 109 functions as a belt static eliminator (
-) AC is superimposed on DC.

The charger 115 functions as a separate charger for the transfer paper, and +) alternating current is superimposed on direct current.

(Process) Referring to FIG. 9, according to method 2, the photoreceptor drum 10
A primary toner image is formed on the (-) toner.

This primary toner image is transferred to the surface of the belt 107 as a mirror secondary toner image by a (+) corona discharge having a polarity different from that of the toner from the charger 108 .

Therefore, in this example as well, the charger 108 is an intermediate transfer means.

Next, the first (as shown in Figure 1, the second by (-) toner)
After the next toner image passes through the cleaner 116 part which is spaced from the belt surface in advance, the toner image (-) of the same polarity as the toner from the charger 108 is placed on the back side of the transfer paper S fed at the same timing. Transferred by corona discharge.

Therefore, the charger 108 also functions as a secondary toner image transfer means.

The transfer paper with the image formed on its back side is transferred to the charger 11.
The fixing means 1 is separated from the belt 107 by the function of 5.
Head to 17.

Method 8 (see Figures 9, 10, and 11).

(Mode) This method is a method of simultaneously forming monochrome images on both sides of the transfer paper, and is carried out in monochrome duplex mode.

This mode selection is also performed in accordance with method 1 above.

The pre-transfer charger 109 inverts the polarity of the (=) toner image on the photoreceptor drum to (+), and the static eliminator 110 removes static electricity from the toner and the photoreceptor so that the transfer in the next process is performed smoothly. It is now possible to do this.

(Process) First, a (-) secondary toner image is formed on the belt 107 by the developing device 106R according to method 2 (see FIG. 9).

Next, as shown in FIG. 11, a (-) mirror latent image is carried on the photosensitive drum 105 by the scanning light L', and this is converted into a (-) primary toner image by the developing device 106R.

Next, this (-) primary toner image is transferred to the i-electronic device 109 before transfer.
The polarity is reversed by the function of +) to form a primary toner image.

The attraction force between the primary toner image and the photoreceptor is weakened by the action of the static eliminator 110, thereby ensuring smooth transfer.

Then, as shown in FIG. 11, the surface of the transfer paper S fed at the same timing (
A primary toner image of +) on the back side and a secondary toner image of (-) on the belt from the charger 108 respectively.
Transfer by corona discharge.

Therefore, in this example, the charger 108 serves as a primary toner image transfer means, an intermediate transfer means, and a secondary toner image transfer means. It should be noted that the polarity of the corona discharge of the charger 108 is switched between the time of secondary toner image formation in method 7 and the double-sided transfer in method 8.

Method 9 (see Figures 9 and 12).

(Mode) This method is a method of forming a two-color image of black and red or a full-color image on the back side of transfer paper, and can be performed in single-sided mode.

This mode selection is also performed in accordance with method 1 above.

The charger 108 is provided with a function of making the transfer voltage variable.

Note that the chargers 109.129.131 are not made to function.

(Process) According to the explanation in FIG. 9 in Method 7, a red secondary toner image (-) is transferred onto the belt 107, and a black latent image is further carried on the photoreceptor drum.

As shown by hatching in FIG. 7, the developing device 10
6B visualizes it as a black primary toner image (-), and the charger 108 compositely transfers it to the red secondary toner image already formed on the belt 107.

At that time, the second secondary toner image transfer is performed for the first secondary toner image transfer.
For the next toner image transfer, the transfer voltage is increased sequentially, but the charger 129 eliminates the charge from the belt and toner to maintain the transfer efficiency.

As shown in FIG.
The image is transferred to the back side of the transfer paper S at step 8, separated from the belt by charger 115 and discharged from the belt, and then sent to fixing means 117.

Incidentally, if a developing means 106' shown in FIG. 2 is used in place of the developing means 106, a single-sided full color image can be obtained.

Method 10 This method is a method of forming a single color image on the front side, two colors on the back side, or a full color image. After forming a color secondary toner image on the belt 107 through a process similar to method 9, a monochrome image is formed on the photoreceptor drum. forming a primary toner image and performing method 8 above;
A monochrome image is transferred to the front side of the transfer paper and a color image is transferred to the back side using a process similar to that of .

Method 11 (see Figure 13).

(Mode) This method is a method for freely forming full-color, two-color images on both sides, and is carried out in a double-sided color mode.

As shown in FIG. 13, four photoreceptor drums 105-1, 105-2, 105-3, 10
It is implemented in a configuration in which 5-4 are arranged side by side.

The photosensitive drum 105-1 is a yellow developer 106"
Y, 105-2 is a developer for magenta 106"M, 105-3 is a developer for cyan 106"C1 105-
4 are each equipped with a black developing device 106''B.

(Process) According to method 9, each developing device 106"Y, 106"M,
A full-color secondary toner image is formed on the belt 107 using 106"C and 106"B, and while this secondary toner image is transferred to the back side of the transfer paper S, on the front side of the transfer paper according to method 8, The monochrome primary toner images on each drum are sequentially transferred in the order in which the paper advances to form full-color images on both sides.

Two-color development is also possible by appropriately selecting the developing device to be used.

Example 3 This example is characterized by the processes shown in FIGS. 14 to 16.

In this example, as shown in FIG. 14, a second charger 140 for applying (-) direct current is disposed above the right end of the belt 107 as a secondary toner image transfer means.

Further, the charger 129 is applied with a direct current superimposed on the alternating current,
It has a function of converting the polarity of the (=) secondary toner image to (+).

With these configurations, the following image formation methods 12 to 15 are possible.

Method 12 (Mote) This method is a method of forming a monochrome image on the surface of transfer paper,
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

Charger 129 and second charger 140 do not function. The charger 115 functions as a separate charger for the transfer paper S.

(process) Follow method 1 above.

Method 13 (see Figures 9 and 13).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
It is done in single-color, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

The charger 129 is used to change the polarity of the secondary toner image.
The second chargers 140 each function as a secondary toner image transfer means.

(Process) Belt 107 according to the explanation of FIG. 9 in method 7 above.
A secondary toner image (=) is formed on top.

Next, this (-) secondary toner image is transferred to the charger 129 (
The polarity is changed to a secondary toner image of +). Then, as shown in FIG. 14, this secondary toner image is transferred to a second charger 140 on the back side of the transfer paper S that is sent at the same timing.
Transfer is caused by (-) charge caused by corona discharge.

Furthermore, it is also possible to enhance the transfer by a (+) corona discharge from the charger 108.

Method 14 (see Figures 9, 14, and 15).

(Mode) This method is a method of simultaneously forming monochrome images on both sides of the transfer paper, and is carried out in monochrome duplex mode.

This mode selection is also performed in accordance with method 1 above.

The mode of voltage application to the chargers is based on method 13.

(Process) According to Method 13, a (-) secondary toner image is created on the belt 107. As shown in FIG. 15, the charger 12
The polarity is reversed at step 9 to form a (+) secondary toner image.

On the other hand, (-) is placed on the photoreceptor drum 105 according to method 12.
Create a primary toner image.

Then, as shown in FIG. 15, the second charger 140 transfers the secondary toner image on the belt to the back side of the transfer paper S that is sent at the same timing.

The primary toner images are each transferred onto the surface of the transfer paper S by the charger 108, and monochrome images are simultaneously formed on both sides of the transfer paper.

Method 15 (see Figure 16).

(Mode) This method is a method of forming a two-color image or a full-color image on the back side of transfer paper, and is carried out in single-sided color mode.

This mode selection is also performed in accordance with method 1 above.

The charger 108 is provided with a function of making the transfer voltage variable.

(Process) According to the explanation of FIG. 7 in method 9, the belt 107
A two-color secondary toner image (=) is formed on top.

Then, as shown in FIG. 16, the polarity of this secondary toner image is changed by a charger 129 to form a secondary toner image (10),
The second charger 140 transfers the image onto the back side of the transfer paper.

Method 1 is a method of forming a single-color image on the front side, a two-color image on the back side, or a full-color image. A color secondary toner image is formed on the belt 107 through a process according to Method 15, a monochrome primary toner image is formed on the photoreceptor drum according to Method 12, and a color secondary toner image is formed on the surface of the transfer paper according to Method 14. A single color image is transferred to the back side, and a two-color image is transferred to the back side. When creating a full color image, a developing means 106' shown in FIG. 2 is used.

Example 4 This example is characterized by the processes shown in FIGS. 17 to 19.

In this example, the charger 129 functions for static elimination.

6. The pre-transfer charger 109 does not function as a polarity converter. The pre-transfer charger 109 functions as a polarity converter of the primary toner image. The static eliminator 110 functions as a static eliminator to facilitate transfer. Charger 140 is supplied with direct current (+) and functions as a secondary toner image transfer means.

Charger 115 is applied with (+) direct current superimposed on alternating current,
Performs the function of separating the transfer paper.

With these configurations, the following image formation methods 17 to 21 are possible.

Method 17 (Mode) This method is a method of forming a monochrome image on the surface of a transfer paper, and is carried out in a monochrome single-sided mode.

This mode selection is also performed in accordance with method 1 above.

(process) Follow method 1.

Method 18 (see Figure 17).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
Performed in monochromatic, single-sided mode.

Selection of this mode is also performed according to the method described above.

(Process) Belt 107 according to the explanation of FIG. 9 in method 7 above.
A (-) secondary toner image is formed thereon.

Next, as shown in FIG. 17, this (-) secondary toner image is neutralized by a charger 129 so that it can be easily transferred, and a second
Transfer is performed by the charger 140.

Charger 108 does not function.

Method 19 (see Figure 18).

(Mode) This method is a method of simultaneously forming monochrome images on both sides of the transfer paper, and is carried out in monochrome duplex mode.

This mode selection is also performed in accordance with method 1 above.

(Process) A (-) secondary toner image is created on the belt 107 according to Method 18. On the other hand, according to method 17, the photosensitive drum 10
A (-) primary toner image is created on 5.

Then, as shown in FIG. 18, the polarity of this (-) primary toner image is reversed by a pre-transfer charger 109 to form a (+) primary toner image, and the charge is further removed by a static eliminator 110.

Furthermore, the second charger 140 first applies the belt 107 to the back side of the transferred transfer paper S at the same timing.
The upper (-) secondary toner image is transferred, and then the (+) primary toner image on the photosensitive drum 105 is transferred onto the surface of the transfer paper S by the action of the charger 108.

The transfer paper S, on which monochrome images have been formed on both sides, is separated from the belt by the charger 115 and sent toward the fixing means. Note that in the method 18 for creating the secondary toner image and the method 19 for double-sided transfer, the charger 108
The polarity of the corona discharge will be switched.

Method 20 (see Figure 19).

(Mode) This method is a method of forming a two-color image or a full-color image on the back side of transfer paper, and is carried out in single-sided color mode.

This mode selection is also performed in accordance with method 1 above.

The charger 108 is provided with a function of making the transfer rolling pressure variable.

(Process) According to the explanation of FIG. 7 in method 9, the belt 107
A (-) two-color secondary toner image is formed thereon.

Then, as shown in FIG. 19, this secondary toner image is neutralized by a charger 129 and transferred to the back surface of the transfer paper S by a second charger 140.

In the case of a full color image, a developing means 106' shown in FIG.
Use.

Method 21 This method is a method for forming a single-color image on the front side, a two-color image on the back side, or a full-color image. forming a two-color secondary toner image on the belt 107 through a process similar to method 20,
Further, according to method 17, a monochrome primary toner image is formed on the photosensitive drum, and according to method 19, a monochrome color image is transferred to the front surface of the transfer paper, and a two-color image is transferred to the back surface. When creating a full color image, a developing means 106' shown in FIG. 2 is used.

Example 5 This example is characterized by the processes shown in FIGS. 20 to 22.

In this example, the charger 129 is applied with a (+) direct current superimposed on the alternating current, so that it functions for polarity reversal and does not function for static elimination. Pretransfer band? The Ii device 109 and the static eliminator 110 do not function. For this reason, illustration is omitted.

The charger 115 performs the function of separating the transfer paper by superimposing (+) on the alternating current.

As shown in FIG. 20, the charger 1 is
A pair of third chargers 150 consisting of an upper charger 150U and a lower charger 150D are arranged facing each other at a position immediately upstream of the charger 15 with the belt 107 and the paper path in between.

With these configurations, the following image formation methods 22 to 26 are possible.

Method 22 (Mode) This method is a method of forming a monochrome image on the surface of transfer paper,
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

(process) According to the method above.

Method 23 (see Figure 20).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

(Process) Belt 10 according to the explanation of FIG. 9 in method 7 above.
A (-) secondary toner image is formed thereon.

Next, the polarity of this (-) secondary toner image is changed to a (+) secondary toner image by the charger 129 as shown in FIG. , the third charger 150 transfers the image. that time,
Upper charger 150U is (-), lower charger 150D
(+) shall be applied.

Charger 108 does not function.

Method 24 (see Figure 21).

(Mode) This method is a method of simultaneously forming monochrome images on both sides of the transfer paper, and is carried out in monochrome duplex mode.

This mode selection is also performed in accordance with method 1 above.

(Process) A (-) secondary toner image is created on the belt 107 according to method 23. On the other hand, according to method 22, the photosensitive drum 10
A (-) primary toner image is created on 5.

Then, as shown in FIG. 21, the polarity of the (-) secondary toner image is reversed by the charger 129, and the polarity is aligned with the back side of the transferred transfer paper at the same timing. on the other hand,
By the action of the charger 10g, the (-) primary toner image on the photosensitive drum 105 is transferred to the front surface of the transfer paper, and at the same time, the secondary toner image on the belt 107 is also transferred to the back surface of the transfer paper. The transfer paper S, on which monochrome images have been formed on both sides, is further transferred securely by the third charger 150, separated from the belt by the charger 115, and sent toward the fixing means.

Method 25 (see Figure 22).

(Mode) This method is a method of forming a two-color image or a full-color image on the back side of transfer paper, and is carried out in single-sided color mode.

This mode selection is also performed in accordance with method 1 above. Charger 108 does not function.

(Process) According to the explanation of FIG. 7 in method 9, the belt 107
A (-) two-color secondary toner image is formed thereon.

Then, the polarity of this secondary toner image is changed by a charger 129 as shown in FIG. 22, and transferred to the back surface of the transfer paper S by a third charger 150.

In the case of a full color image, a developing means 106' shown in FIG.
Use.

Method 2 is a method of forming a single-color image on the front side, a two-color image on the back side, or a full-color image. A two-color secondary toner image is formed on the belt 107 through a process according to method 25, a monochrome primary toner image is formed on the photoreceptor drum according to method 22, and a transfer paper is formed according to method 24. A single color image is transferred to the front side, and a two-color image is transferred to the back side. When creating a full color image, a developing means 106' shown in FIG. 2 is used.

Example 6 This example is characterized by the processes shown in FIGS. 23 to 25.

In this example, the charger 129 functions for static elimination and does not function for polarity change.

Before transcription? The IF device 109 functions to change the polarity of the primary toner image. The static eliminator 110 functions as a static eliminator that facilitates transfer. Charger 140 is not shown because it does not function.

The charger 115 is applied with a (+) direct current superimposed on the alternating current, and performs the function of separating the transfer paper.

Regarding the third charger 150, the upper charger 150U
It is assumed that voltage is applied to (+), and voltage is applied to lower charger 150D (-).

With these configurations, the following image formation methods 27 to 31 are possible.

Method 27 (Mode) This method is a method of forming a monochrome image on the surface of transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

(process) Follow method 1.

Method 28 (see Figure 23).

(Mode) This method forms a monochrome image on the back side of the transfer paper.
Performed in monochromatic, single-sided mode.

This mode selection is also performed in accordance with method 1 above.

(Process) Belt 107 according to the explanation of FIG. 9 in method 7 above.
A (-) secondary toner image is formed thereon.

Next, as shown in FIG. 23, this (-) secondary toner image is neutralized by a charger 129 so that it can be easily transferred.

The charger 108 and the third charger 150 transfer the image onto the back side of the transfer paper S fed at the same timing.

Method 29 (see Figure 24).

(Mote) This method is a method in which monochrome images are simultaneously formed on both sides of a transfer sheet, and is carried out in a monochrome duplex mode.

This mode selection is also performed in accordance with method 1 above.

(Process) A (-) secondary toner image is created on the belt 107 according to Method 28, and the charge is removed by the charger 129. One hand force method 2
7, a primary toner image of (=) is created on the photosensitive drum 105.

Then, as shown in FIG. 24, the polarity of this (-) primary toner image is reversed by the pre-transfer belt rri device 109, and the (+) primary toner image is
Next, a toner image is formed, and the static electricity is further removed by a static eliminator 110.

Then, the charger 108 first applies the (
-) is transferred to the charger 108 at the same time.
The (+) primary toner image on the photosensitive drum 105 is transferred onto the surface of the transfer paper. The transfer paper S, on which monochrome images have been formed on both sides, is transferred further by the third charger 150, and then separated from the belt by the charger 115 to eliminate static electricity, and is sent toward the fixing means.

Note that when creating the secondary toner image in method 28 and this method 2,
9, the polarity of the corona discharge of the charger 108 is switched.

Method 30 (see Figure 25).

(Mode) This method is a method of forming a two-color image or a full-color image on the back side of transfer paper, and is carried out in single-sided color mode.

This mode selection is also performed in accordance with method 1 above.

The charger 108 is provided with a function of making the transfer rolling pressure variable.

(Process) According to the explanation of FIG. 7 in method 9, the belt 107
A (-) two-color secondary toner image is formed thereon.

Then, as shown in FIG. 25, this secondary toner image is neutralized by a charger 129 and transferred to the back surface of the transfer paper S by a third charger 150. Here charger 108
doesn't work.

In the case of a full color image, a developing means 106' shown in FIG.
Use.

Method 31 This method is a method for forming a single-color image on the front side, a two-color image on the back side, or a full-color image. forming a two-color secondary toner image on the belt 107 through a process similar to method 30;
Also, according to Method 27, a single-color toner image is formed on the photosensitive drum, and according to Method 29, a single-color image is transferred to the front surface of the transfer paper, and a two-color image is transferred to the back surface. When creating a full color image, a developing means 106' shown in FIG. 2 is used.

Example 7 This example is an electrophotographic apparatus equipped with one image forming body.

In a double-sided copying method for a recording device such as an electrostatic recording copying machine or a printer, a first toner image serving as a back side image of the double-sided copy is transferred from the image forming body to an intermediate transfer body, and the first toner image is transferred from the image forming body to an intermediate transfer body. A one-sided copy is obtained by overlaying a transfer paper on the toner image and then transferring a second 1 to toner image, which becomes the surface image of the double-sided copy, onto the surface of the transfer paper, as shown in FIGS. 26 to 33. This is implemented using the configuration shown in .

FIG. 26 is a schematic configuration diagram showing an example of a color recording apparatus applied to this example, and reference numeral 1 denotes a photoreceptor belt (hereinafter referred to as "P").
2 is a PC moving roller for supporting and rotating one end side of the PC belt (image forming body) 1, and 3 is a rotating roller for freely rotating the other @ side of the PC belt 1. A PC driven roller for supporting, reference numeral 4 a charger for charging the PC belt 1 by 1F, reference numeral 5 an optical writing unit for forming a color-corresponding electrostatic latent image on the PC belt 1, reference numeral 7.9. 11.13 is a developing device for developing a latent image corresponding to each color, and 6.8.10.12 is each of the above-mentioned developing devices 7.
．． 9.11.13 Developing roller equipped with code 14.
33 and 34 are transfer paper, 15 is a paper feed roller for feeding the transfer paper 14 into the recording device, 16 is a registration roller, and 17 is a transfer section and a fixing section for feeding the transfer paper 14 into the recording device. 18 is a transfer roller that supports and rotates one end of the transfer belt 17, and 19 is a transfer belt 17.
A driven roller rotatably supports the other end side; reference numeral 20 is a belt contact/separation switching roller for bringing the transfer belt 17 into contact with and away from the PC belt 1; reference numeral 21 is a belt contact/separation switching roller for transferring the developed image on the PC belt 1; a transfer charger for transferring onto paper 14;
Reference numeral 22 is a charger for removing electricity from the transfer belt 17, reference numerals 14, 33, and 34 are transfer paper, and reference numeral 15 is a paper feed roller for feeding the transfer paper 14 into the recording apparatus.
Reference numeral 16 indicates a registration roller; reference numeral 17 indicates a transfer belt serving as a transfer paper supporting and conveying member for conveying the fed transfer paper 14 to the transfer section and the fixing section; and reference numeral 18 indicates the transfer belt 17.
A drive roller for supporting and rotating one end side, reference numeral 19
20 is a driven roller that rotatably supports the other end of the transfer belt I7, 20 is a belt contact/separation switching roller for bringing the transfer belt 17 into contact with and away from the PC belt 1, and 21 is P.
A transfer charger for transferring the developed image on the C-belt 1 to the transfer paper 14; reference numeral 22 is a static elimination charger for removing charge from the transfer belt 17; reference numeral 23 is an electrostatic attraction for the transfer paper 14 to the transfer belt 1-17; 24 is a transfer paper separation charger for separating the transfer paper electrostatically attracted to the transfer belt 17; 25 is a transfer paper separation charger for separating the transfer paper electrostatically attracted to the transfer belt 17; A transfer paper conveyance belt cleaner for removing the transfer paper, 26 a paper path switching conveyance belt for switching the conveyance direction of the transfer paper after transfer, 27 a paper leading edge guide plate, 28 a paper trailing edge guide plate,
Reference numeral 29 is a PC belt cleaner for removing residual toner on the PC belt 1 after transfer, reference numeral 30 is a static eliminator for removing electricity from the PC belt 1, and reference numeral 31 is for fixing the image transferred to the transfer paper. This fixing means is substantially the same as the fixing means 117 in FIG.

Reference numeral 32 is a paper discharge tray for discharging the transfer paper after the image is fixed, reference numeral 35 is a color image reading device for reading the color image of the document, reference numeral 36 is a toner polarity reversal charger, and reference numeral 37 is a toner polarity reversal charger. Opposed 11i 1m for 36.

Next, the operation of the above configuration will be explained with reference to FIGS. 27 to 33.

As shown in FIG. 27, the PC belt 1 is negatively charged and a normal image is exposed by the light=3-inclusive unit 5.

Next, as shown in FIG. 28, development (reversal) is performed using negatively charged toner, and this is used as a first toner image 38.

Subsequently, as shown in FIG. 29, 5.5 KV is applied to the transfer charger 21 to transfer the image onto a transfer belt 17 (intermediate transfer member) which is a biaxially stretched polyester belt having a thickness of 75 μm. The counter polarity of the first toner image 38 on the belt 17 is set to +5. Apply OKV to reverse from negative to positive. As a result, when the entire screen is reversed (when the rear end of the screen is at Q2), the moving direction of the transfer belt 17 is reversed. The tip of the image is Q.

(The transfer belt cleaner 25 is kept in a non-contact state until the transfer belt cleaner 25 returns to the PC belt 1 so as not to contact it until the third
As shown in FIG. 1, the direction of the transfer belt 17 is reversed again. Next, the transfer paper 14 is fed with timing and aligned with the screen of the first toner image 38, and as shown in FIG. The paper 14 is electrostatically attracted to the transfer belt 17. At the same time, the first toner image 38 whose polarity has been reversed to positive is transferred from the transfer belt 17 to the transfer paper 14.

Further, as shown in FIG. 33, the mirror image of the negatively charged toner image 39 (second toner image) similarly formed on the PC bell 1-1 is aligned with the screen, and the +5
．． 5 is applied to transfer the second toner image 39 onto the surface of the transfer paper 14. Next, the transfer paper 14 having the toner images 38, 39 on both sides is transferred from the transfer belt 17 to the paper path switching conveyance belt 26 rotating at the same speed as the transfer paper 14, and sent to the fixing device 31 where it is fixed on both sides at the same time.

When the rear edge of the screen mentioned above is Q2, if you want to reverse the moving direction of the transfer belt 17, if the screen is A3 size, move the transfer belt 17 as it is without reversing it so that the leading edge is Q,
It would be faster to have it come to

Further, when transferring the transfer paper 14 to the paper path switching conveyance belt 26, in the case of two or more colors, after the second toner image 39 is completed, it is sent to the fixing means 31, and before that, it is sent to the paper leading edge guide plate 27.

In FIG. 33, +5.5KV is applied to the transfer charger 21.
When applying the first toner image 38, it is possible to transfer the first toner image 38 at the same time at this point, without having to transfer the first toner image 38 by the paper suction charger 23 as shown in FIG. 7 (even if the applied voltage is 0.times.).

As described above, according to Example 7, the back image (first toner image) is transferred to the intermediate transfer member (transfer belt 17), so it is transferred to paper and fixed.

Compared to conventional devices that transport and refeed paper, the distance the back image moves is shorter and the copying speed is faster.There is no positional shift, so there is no magnification error, and the paper transport is short and straight. Because it is close to the original size, jams do not occur, and it is also possible to copy large sheets of paper or small sheets of paper such as oysters.

In Examples 1 to 6 described above, the photosensitive drum 10
Each time a primary toner image of one type of toner is formed on the toner 5, it is transferred to the transfer paper S or the belt 107.

In the present invention, the present invention is not limited to the above example, but after forming a primary toner image consisting of many types of toner images on the photoreceptor drum 105, this primary toner image is transferred to transfer paper S or Bel l-107. You can also.

This primary 1-toner image consisting of many types of toner images is: ■ A composite image of multiple images using only black toner, ■ A composite image of an image of any color and an image of any other color, ■ Any two
Examples include a multi-color image with more than one color, and a full-color image.

To perform such image formation, it is necessary to create at least two types of toner images on the photoreceptor drum, and the process for this is described, for example, in ``Fundamentals and Applications of Electrophotographic Technology'' (Electrophotographic Technology Edition). , Corona Publishing, S 63
．． 6.15 P562-P565) shall apply.

Therefore, the above publication is reproduced below.

``Digital Multicolor Printing Method'' A single-function one-time transfer method is being considered as a method for forming multicolor prints using a digital method.

The single-function one-time transfer method is a method in which a multicolor toner image is formed on a photoreceptor by a nine-color superimposed IJA image, and a color image is formed in one transfer.

Generally, in optical printers, emphasis is placed on fine lines such as characters, so a negative-positive reversal phenomenon, which has excellent fine line reproducibility, is often used as a developing method. Next, the image forming process of a red and black two-color image by negative-positive reversal development will be explained based on FIG. 45.

In Figure 2, reference numeral 200 is a photoreceptor, 201 is a corona charger, 202 is a black signal light, 203 is a black toner, 204 is a scorotron charger, 205 is a red signal light, and 206 is a red toner. are shown respectively.

(1) Charging: The surface potential of the photoreceptor is V by corona discharge.

becomes positively charged.

(2) Image exposure: Expose to black negative signal light.

The surface potential of the exposed area, which becomes the image area, is optically attenuated and becomes the residual potential of the photoreceptor (8).

(3) Black development: Reverse development is performed using positively charged black toner to form a black toner image. At this time, the surface potential of the area developed with the black toner increases by an amount equivalent to the potential of the black toner.
Initial potential of photoreceptor■. It won't be. That is, the black toner adhering portion still has the ability to adhere toner. Therefore, if development is performed with 51 toner and then reverse development is performed with red toner, the red toner will adhere on top of the black toner.

In order to prevent this, it is necessary to return the surface potential of the black toner adhered portion to the initial potential vo of the photoreceptor before forming the red toner image.

(4) Recharging The photoreceptor is charged again using a Niscorotron charger to bring the surface potential of the smoked toner-attached area to the same potential as that of the undeveloped area. At this time, the toner layer in the black toner adhesion area and the photosensitive layer are charged in inverse proportion to the capacitance of each layer.

(5) Optical image exposure: Expose to red negative signal light.

(6) Red development: Reverse development with red toner.

Next, the two-color toner images are simultaneously corona-transferred onto image-receiving paper and fixed by heating to obtain a two-color print.

The process for forming a two-color image has been described above, but a three-color image can be obtained by repeating steps (4) to (6) using a third 1-ner. Further, full color images can be obtained by using tC+M and Y toners. To reproduce a full-color image, a latent image must be formed by exposing the toner image to light. Therefore, in order to sufficiently charge the photoreceptor in the re:IF charging step (4), a photoreceptor is used in which the capacitance of the photosensitive layer is smaller than the capacitance of the toner layer. ” In the present invention, in order to apply the above process, in the recording device shown in FIG.
A surface flexible recording device replaced with the developing means 106' shown in the figure or a surface flexible recording device shown in FIG. 26 is used. In these cases, the main charger 114 serves as the corona charger 101 and the scorotron charger 104.

Further, the scanning beam as an exposure means is single, and after exposure with this single beam with image information of -, the toner image obtained on the photoreceptor drum 105 by development is added with other image information of -. When adopting a method in which a superimposed toner image is formed on the photoreceptor drum 105 by exposure and development with the above-mentioned scanning beam containing In order to appropriately move the belt 107 away from the photosensitive drum 105 and bring it close to the photosensitive drum 105 during transfer, a contacting and separating means is provided.

For the same reason, the cleaner 112 is also made to be able to move toward and away from the photoreceptor drum 105, and the developing method of the developing means 106 adopts a so-called jumping development method, and the distance between the photoreceptor drum and the developing sleeve is 0.1~ A distance of 0.2 mm is provided to avoid image disturbance, and development is performed by blowing off toner by applying a required bias voltage. A primary toner image consisting of multiple types of toner images is created by simultaneously exposing with multiple beams containing image information corresponding to different colors or different image information, and developing the latent images resulting from this exposure simultaneously with different developing sleeves. If a method is adopted in which a toner image is created and transferred all at once, the means for bringing the intermediate transfer body into contact with and separating it from the intermediate transfer member is not necessary, and the jumping development method is, of course, not an essential condition.

A specific example will be explained below. In addition, on each side below, the primary
~The toner image will be explained as a two-color toner image, red and black. When obtaining a full color image (not described), a multicolor image, or a monochrome image, a primary toner image may be created by repeating exposure and development a required number of times. Furthermore, mode switching for executing each method is performed by operating a selection button switch on the operating section, and is executed by a control means using a CPU. Hereinafter, for each side, a method of forming an image on the front side of the transfer paper, a method of forming an image on the back side of the transfer paper, and a method of forming an image on both sides of the transfer paper will be explained.

Example 8 This example is a modification of Example 1. Therefore, except for the fact that the primary toner image formed on the photoreceptor drum is made up of multiple types of toner images and the process to create such an image, the following example describes the process to obtain the final copy. 1
In accordance with the process of

Method 32 (see Figures 36 and 37).

This method corresponds to method 1 and is a method of forming an image on the surface of transfer paper, and is carried out in a composite single-sided mode. The method 1 above applies to various chargers and other voltage application methods of 1 m.

(Process) As shown in FIG. 36, the belt 107 and cleaner 112
A primary 1-toner image is formed on the photoreceptor drum 105 in a position where the imager is not in contact with or separated from the photoreceptor, that is, in a state where it is retracted in the direction shown by the arrow. First, during the first rotation of the photoreceptor drum 105, a latent image for an optical image is created on the photoreceptor drum by the scanning light L' from the optical writing means and developed by the developing device 106R. A point image latent image is created by ', and developed by a developing device 106B.

It is assumed that the scanning by the scanning light L' is controlled to be written as a mirror latent image in order to make the image on the transfer paper surface a normal image. In this way, a primary toner image is formed on the photoreceptor drum 1o5. The primary toner image is a composite image of a mirror red toner image and a mirror black toner image.

In the figure, the red toner image has a polarity symbol enclosed in a circle.
A black toner image is shown as a polarity symbol enclosed in a circle with diagonal lines.

After the primary toner image is thus formed on the photosensitive drum 105, the belt 107 is brought into contact with the tram as shown in FIG.
2 is brought into contact with the drum, and the primary toner image is transferred onto the surface of the transfer paper S carried on the belt. This transfer is performed in the charger 108 by a (+) corona discharge having a different polarity from each toner of the primary toner image.

Method 33 (see Figure 38).

This method corresponds to method 2, and is a method of forming an image on the back side of the transfer paper, and is carried out in a composite single-sided mode.

Regarding each charger and other voltage application modes, the method 2 is applied.

(Process) In this method, the primary toner image on the photosensitive drum 105 is once transferred to the belt 107, and then transferred to transfer paper to obtain a copy. Therefore, in order to make the image on the transfer sheet a normal image, the scanning by the scanning light is controlled so that the latent image of the work is carried on the surface of the photoreceptor drum.

As shown in FIG. 38, the primary toner image formed on the surface of the photoreceptor drum as a normal image becomes a mirror image on the surface of bells 1 to 07 due to the (+) corona radiation of opposite polarity to the toner from the charger 108. It is transferred as a secondary toner image. after that,
This secondary toner image is charged with a charger 131, and
After the polarity is changed to (+) by the charger 129, the charger 1.08 to 1-
The image is transferred by a (+) corona discharge that has the same polarity as the toner.

Method 34 (see FIGS. 38 and 39), which corresponds to method 3, is a method in which images are simultaneously formed on both sides of the transfer paper, and is carried out in a composite duplex mode.

(Process) According to method 33, a (-) secondary toner image is carried on the belt 107 by transfer (see FIG. 38).

Next, the polarity of this secondary toner image is changed to (+) according to method 33 above.

On the other hand, according to method 32, a (-) primary toner image is created on the surface of the photoreceptor tram, the above primary toner image is formed on the front side of the transfer paper S carried on the belt 1.07, and the above 2 toner image is formed on the back side of the transfer paper S. The next toner images are simultaneously transferred by the (+) corona discharge of the charger 108 to form toner images on both sides and sent to the fixing means 117.

Example 9 This example is a modification of Example 2. Therefore, the process of obtaining the final copy is the same as that of Example 2, except that the primary toner image formed on the photoreceptor is composed of a red and black toner image, and the process for creating such an image is different. In accordance with Image formation on the surface of the transfer paper is performed according to method 32. To form an image on the back side, method 33 is followed. Hereinafter, a method for forming images on both sides will be explained.

Method 35 (see Figure 40).

This method corresponds to Method 8, and is a method of simultaneously forming images on both sides of the transfer paper, and is carried out in a composite duplex mode.

The charger 108 has (+) polarity when creating a secondary toner image;
During double-sided transfer, it is switched to (-) polar corona discharge.

(Process) According to method 33, a (-) secondary toner image is obtained on Bell 1-107J. On the other hand, according to method 32, (
-) obtain a primary toner image. Then, the polarity of this (-) primary toner image is reversed to (+) by a pre-transfer charger 109. Then, the adhesion force between the primary toner image and the photoreceptor is weakened by a static eliminator 129 in order to ensure smooth transfer.

Then, the transfer paper S is fed at the same timing.
(+) primary toner on the surface of the photoreceptor drum] 05 -
The (-) secondary toner image on the belt 107 is transferred to the back surface by the (-) corona discharge from the charger 108, respectively.

Example 10 This example is a modification of Example 3. Therefore, except for the difference in that the primary toner image formed on the photoconductor consists of a red and black toner image and the process to create such a 1-toner image, the following is an example of the process to obtain the final copy. Follow the process in step 3. To form an image on the surface of the transfer paper, method 32 is followed. Method 3 to form an image on the same back side
A primary toner image of a red and black 1-toner image is created on the photoreceptor tram according to Method 13. Next, a method of forming images on both sides will be explained.

Method 36 (see Figure 41).

This method corresponds to method 14, and is a method of simultaneously forming images on both sides of the transfer paper, and is carried out in a composite duplex mode.

(Process) A primary toner image of red and black toner is created on the surface of the photoreceptor drum according to method 33, and this primary toner image is further transferred onto the belt 107 according to method 7 to form a (-) secondary toner image. Make a statue. This is polarized by a charger 129 to form a (+) secondary toner image.

Meanwhile, (-) is placed on the photoreceptor drum 105 according to method 32.
Create a primary toner image.

Then, as shown in FIG. 41, the second charger 140 transfers the secondary toner image on the belt 107 onto the back side of the transfer paper S that is sent at the same timing.
by charger 108 on the surface of.

The primary toner images are transferred to form red and black images simultaneously on both sides of the transfer paper.

Example 11 This example is a modification of Example 4. Therefore, the process to obtain the final copy is the same as in Example 4, except that the primary toner image formed on the photoreceptor is composed of red and black toner images, and the process to create such a toner image is different. Follow the process. To form an image on the surface of the transfer paper, method 32 is followed. To form an image on the same back side, method 3
A primary toner image of a red and black toner image is created on the photosensitive drum according to Method 3, and the following procedure is carried out according to Method 18. Next, a method of forming an image on the back side will be explained.

Method 37 (see Figure 42).

This method corresponds to method 19 and is a method of simultaneously forming images on both sides of the transfer paper, and is carried out in a composite duplex mode.

The charger 108 has (+) polarity when creating a secondary toner image;
During double-sided transfer, it is switched to (-) polar corona discharge.

(Process) A primary toner image of a red and black toner image is created on the surface of the photoreceptor drum according to method 33, and this primary toner image is further transferred onto the belt 107 according to method 7 to form a (-) secondary toner image. Make a statue. The charger 129 removes the charge so that it can be easily transferred.

Meanwhile, (-) is placed on the photoreceptor drum 105 according to method 32.
Create a primary toner image.

Then, as shown in FIG. 42, the polarity of this (-) primary toner image is reversed by a pre-transfer charger 109, and the charge is further removed by a charge remover 110.

Furthermore, the second charger 140 first applies the belt 107 to the back side of the transfer paper S that is sent at the same timing.
The upper (-) secondary toner image is transferred, and then the (+) primary toner image on the photosensitive drum 105 is transferred onto the surface of the transfer paper S by the action of the charger 108.

The transfer paper S, on which red dot images are formed on both sides, is separated from the belt by the charger 115 and sent toward the fixing means.

Example 12 This example is a modification of Example 5. Therefore, the process to obtain the final copy is the same as in Example 5, except that the primary toner image formed on the photoreceptor is composed of red and black toner images, and the process to create such a toner image is different. Follow the process. To form an image on the surface of the transfer paper, method 32 is followed. To form an image on the same back side, method 3
3, a primary image is created by a red and black toner image on the photoreceptor drum.
〜Create a color image, and proceed according to Method 23 below. Next, a method of forming images on both sides will be explained.

Method 38 (see Figure 43).

This method corresponds to method 24 and is a method of simultaneously forming images on both sides of the transfer paper, and is carried out in a composite duplex mode.

(Process) A primary toner image of red and black 1-toner image is created according to method 33, and transferred onto the belt 107 according to method 7 (-
) to create a secondary toner image.

Meanwhile, (-) is placed on the photoreceptor drum 105 according to method 32.
Create a primary toner image.

Then, as shown in FIG. 43, the charger 129 inverts the polarity of the (-) secondary toner image and sends it at the same time to match the back side of the transfer paper S. At the same time, the (-) primary toner image on the photosensitive drum 105 is transferred to the surface of the transfer paper, and at the same time the secondary toner image on the belt 107 is also transferred to the back surface of the transfer paper.In this way, two-color images are formed on both sides. The transferred transfer paper S is further ensured to be transferred by a third charger 150, separated from the belt by a charger 115, and sent toward a fixing means.

Example 13 This example is a modification of Example 6. Therefore, except for the difference in that the primary toner image formed on the photoreceptor is composed of multiple types of toner images and the process to create such a toner image, Example 6 is the same as the process to obtain the final copy. In accordance with the process of

To form an image on the surface of the transfer paper, method 32 is followed. To form an image on the back side, create a primary toner image of red and black toner on the photoreceptor drum according to method 33,
Hereinafter, method 28 will be followed. Next, a method of forming images on both sides will be explained.

Method 39 (see Figure 44).

This method corresponds to method 29 and is a method of simultaneously forming images on both sides of the transfer paper, and is carried out in a composite duplex mode. The charger 108 is switched to (+) polarity during secondary toner image formation and to (-) polarity corona emission Ia during double-sided transfer.

(Process) Primary 1 to toner images of red and black toner images are created on the surface of the photoreceptor drum according to Method 33, and this primary toner image is further transferred onto the belt 107 according to Method 7 to form (-) 2. Next, create a toner image.

Meanwhile, (-) is placed on the photoreceptor drum 105 according to method 32.
Create a toner image.

Then, as shown in FIG. 44, this (-) primary toner image is polarized by a pre-transfer charger 109 to become a (+) primary toner image, and is further neutralized by a static eliminator 110.

At the same time, the secondary primary image on the belt 107 is transferred by the corona discharge of the charger 108 onto the back side of the transferred transfer paper, and at the same time the plow of the charger 108 is transferred. on the photoreceptor drum 105 (
+) is transferred to the surface of the transfer paper.

The transfer paper S, on which red and black images have been formed on both sides, is transferred further by the third charger 150, and is then separated from the belt by the charger 115 to eliminate static electricity, and is sent toward the fixing means.

In each of Examples 1 to 12 above, (a) a method of forming an image on the front side of the transfer paper, (b) a method of forming an image on the back side of the transfer paper, and (c) a method of forming an image on both sides of the transfer paper. As explained above, the advantages of these are as follows.

1. By selecting (a) or (b) above, it is possible to make monochrome, multicolor, or full-color copies on either the front or back side of the transfer paper. For example, some users may request that the copy be ejected from the back side of the copier because they do not want others to see the copy, or they may request that the copy be ejected from the front side from the copier when they want to immediately check the finished copy. may be requested, and we can respond to each case. It is also convenient for page alignment when copying one copy from multiple originals.

2. According to (a) above, copying onto the surface of the transfer paper requires only one transfer process, thereby avoiding a reduction in copy speed, and since it is one rotation, high image quality can be maintained.

3. According to (b) above, since the intermediate transfer belt also serves as a paper conveyance belt, there is no separation trouble from the photoconductor as in conventional black and white copying machines, and there is no possibility of jams or damage to the photoconductor. This method is economical because it does not require a special progressive member, and has high reliability in transfer paper conveyance performance.

4. Copy productivity can be increased by the above (a), (b), and (c), and image quality and reliability can be improved.

5. Full-color and multi-color double-sided copies can be created using (c) above.

6. With the above (c), it is possible to prevent the occurrence of image deviation, transfer unevenness, transfer paper skew, folding, wrinkles, etc., which are considered to be most difficult in conventional multi-color and full-color copying machines.

7. Due to the above (c), there is no need to use a sheet clipper to hold the transfer paper on the transfer drum as in the past, so full-color or multi-color image copying is possible.

8. In the above (a), (b), and (c), it is possible to carry the transfer paper in a stray 1-conveyance, and to carry it by electroadsorption in 11f1 using a belt as an intermediate transfer body, and paper-free conveyance of small to large sizes is also possible. It is. Further, monochrome single-sided copying, which is most frequently used by users, can be efficiently performed on both the front and back sides.

Example 14 (see Figures 1, 26, 34, and 35)
.

This example relates to fixing means 31, 117, etc. on each side.

A pair of rollers 117A constituting these fixing means,
, 117B, each roller has a heat source or is configured as a heat roller.

Therefore, the fixing process is completed by passing the transfer paper, on which unfixed toner images are formed on both sides, through the fixing means once, as seen on each side. Also, one surface
Even when an image is formed on any of the back sides, fixing can be performed without reversing the paper.

Therefore, compared to the conventional example in which the paper had to pass twice through the fixing unit where only one of the paired rollers was configured as a heating roller, the effects of heat shrinkage can be minimized, and image misalignment and wrinkles can be minimized. , problems such as paper folding can be solved. Also,
Since there are two heating rollers, the service life of the rollers is also extended.

Furthermore, as a modified example, for each of the upper and lower opposing rollers,
By making the roller surface roughness different from each other, it is possible to obtain a desired gloss level for copies where one side is in color and the other side is in black and white.

By the way, we prepared opposing rollers with large and small surface roughness, and compared the toner adhesion amount on the image surface of each roller with a relatively small amount of about 0.3 mg/am2 and about 1.2 mg/cm2. When the glossiness of the fixed image surface was examined while changing the fixing temperature depending on the number of targets, the characteristics shown in FIG. 35 were obtained.

In FIG. 35, curve B1 uses a roller with a rough surface roughness, and characteristic 1 curve B2 when an image with a toner adhesion amount of 1 or 2 mg/am2 is fixed uses the same roller.
The characteristics when fixed are shown for images with a toner adhesion amount of 0 and 3 mg/cm2, respectively.

Similarly, curve A1 uses a roller with rough surface roughness, and characteristic 1 when fixing an image with toner adhesion Ek of 1.2 mg/cm2. Curve A2 uses the same roller and fixes an image with toner adhesion: Iit of 0.3 mg/cm2. The characteristics of each are shown when they are firmly established.

When the above-mentioned rollers are used facing each other, the temperature at the facing portion including the roller nip portion is common, and this becomes the fixing temperature. Then, fixing temperatures T2 to T3 are set in a temperature range excluding the cold offset generation area where the fixing temperature is T0 or lower and the hot offset generation area where the fixing temperature is 14 or higher, and which is set slightly inside the temperature of each area above for safety. The temperature range can be said to be a "preferred fixing temperature range" common to each roller in which offset can be avoided.

On the other hand, regarding glossiness, a glossiness of 20% or more is a preferable range for full-color images, and a glossiness of 5% or less is a preferable range for black-and-white images.

If a pair of fixing rollers is constructed by arranging a roller with a rough surface roughness and a roller with a fine surface roughness to face each other, the opposing portions of both rollers, that is, the temperature of the fixing portion, will be at a common temperature as described above, and this temperature will be the fixing temperature. At this common fixing temperature, rollers with fine surface roughness are used for full color fixing, and rollers with rough surface roughness are used for black and white fixing.

Specifically, as shown in FIG. 34, the upper roller is provided as a pair of rollers 117'A with a coarse surface roughness, and the lower roller is provided as a pair of rollers 117'B with a fine surface roughness.
By forming a black toner image on the front side and a color toner image on the back side, the color image can be printed with a gloss level of 20.
It is possible to obtain copies with an appropriate gloss level depending on each image characteristic, such as a gloss level of 5% or higher for monochrome images or a gloss level of 5% or higher for black and white images.

Incidentally, the structure of the pair of rollers 117'A includes a halogen heater H in the center, a cylindrical core metal 160 made of AQ, Fe, etc. surrounding this heater, and a Si rubber layer 170 covering the periphery of the core metal.

Further, the roller pair 117'B has the same configuration as the roller pair 117'A described above except for the outermost layer, and the outermost layer 171
The bottom surface is spray-coated with Sl-based rubber and has an extremely fine rough surface.

Various rubbers such as HTV, RTV, and LTV can be used as the Se-based rubber, and are appropriately selected in consideration of toner releasability, fixing temperature range, durability, and the like.

To make the surface rougher finer, perform surface polishing, spray coating with mold release agent, etc.

As mentioned above, when a low gloss level is preferred, such as for black-and-white copying, a roller with rough surface roughness is used, and when a high gloss level is preferred, such as for color copying, the opposite roller can be used. good.

(Effects of the Invention) According to the present invention, copying can be realized with a simple and compact configuration without using any reversing means.

Furthermore, it is possible to fix either the front or back side with one pass of paper. Therefore, in double-sided copying, there is little effect of thermal shrinkage of the paper, and image shift, paper wrinkles, folds, etc. do not occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 and 26 are diagrams illustrating the configuration of a recording apparatus suitable for carrying out the present invention, FIG. 2 is an explanatory diagram of the developing means, and FIGS. 3 to 25, and 36 to FIG. 44 is a diagram explaining how to form an image, FIG. 27 is an explanatory diagram showing charging and exposure on the PC bell 1, FIG. 28 is an explanatory diagram showing the first toner image, and FIG. 30 is an explanatory diagram showing the toner polarity reversal. FIG. 31 is an explanatory diagram showing the reversal of the transfer belt. FIG. 32 is an explanatory diagram showing the back side transfer. is an explanatory diagram showing surface transfer, the third
FIG. 4 is an explanatory diagram of the fixing roller, FIG. 35 is an explanatory diagram of the fixing characteristics, and FIG. 45 is an explanatory diagram of the image forming process of a red and black two-color image.

l... Photoreceptor belt, 5... Optical writing 2-nit.

7, 9.11.13...Developer, 14.33.34.
S... Transfer paper, 17... Transfer belt, 21... Transfer charger, 23... Paper adsorption charger, 31.1
17...Fixing means.

104... Rotating mirror, 105... Photosensitive drum,
106.106'...Developing means, 107...Belt, 108...Charger, 117...Fixing means, 1
17A, 117'A, 117B.

117' B... Opposing roller, 140... Second charger, 150... Third charger.

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Claims (1)

[Scope of Claims] 1. An optical writing means capable of writing an image on a writing target as a normal image or a mirror image; a rotatable photoreceptor as the writing target; a developing means for visualizing the written latent image as a primary toner image; a belt serving as an intermediate transfer member disposed opposite to the photoreceptor and configured to freely pass a transfer sheet between the opposed members; a primary toner image transfer means for transferring the toner image to the transfer paper; an intermediate transfer means for transferring the primary toner image to the belt as a secondary toner image; and a transfer means for transferring the secondary toner image to the belt. A surface-adjustable recording device comprising a secondary toner image transfer means for transferring onto paper. 2. The surface-adjustable recording device according to claim 1, wherein the belt serving as the intermediate transfer member also serves as conveyance means for the transfer paper. 3. In claim 1, the fixing means for fixing the toner image on the transfer paper sent out from the belt is constituted by opposing rollers for passing the paper, and each of these rollers is a heated roller. Surface flexible recording device.