JPS63135970A - Printing device - Google Patents

Abstract

PURPOSE:To perform an image formation by a concurrent processing method and to transfer the image on the sheet of plain paper at the time of high humidity, by using the mixed toner of an electric conductive toner and insulating toner, and setting the same polarity of the frictional electrification of the insulating toner as that of charge injected in the electric conductive toner at the time of exposing an image. CONSTITUTION:As toner, mixed toner 7 is used in which the electric conductive toner 24 having magnetism whose resistance ratio is less than 10<8>OMEGAcm, and the insulating toner 25 having the magnetism resistance ratio is more than 10<9>OMEGAcm are mixed in a weight mixture ratio of the electric conductive toner to the insulating toner 1:(0.1-10). Furthermore, the polarity of the frictional electrification of the insulating toner 25 is set at the same polarity as that of the charge injected in the electric conductive toner 24 at the time of exposing the image. At the time of transfer, since an electric field in which electrostatic force can act on the electric conductive toner 24 and the insulating toner 25 from an image forming body 4 in the direction of a recording medium 17 is applied, a toner image is transferred on the recording medium 17 according to a regular electrostatic transfer principle. At this time, transfer property can be secured even at the time of high humidity because the insulating toner 25 is used.

Description

[Detailed Description of the Invention] [Field of Application] Regarding the printing method using the so-called xerography technology using the original conductor r for the unexploded 8A. Concerning a printing method utilizing new xerographic technology.

[Conventional technology]

In recent years, various printing methods using xerography technology have been put into practical use and used. To give an overview of the toners used in this technology, in the case of a printing method that fully utilizes the "Carlson process", insulating non-magnetic toner, in two-component magnetic brush development method and float electrode effect development method (Fmgo method), In the jumping development method, a HalIA edged magnetic toner is used, and in the case of electrofax, a four-tolerant magnetic toner is used.

Recently, a method using new xerography technology (hereinafter referred to as the "simultaneous method") in which images are formed by simultaneously performing image formation and development, which has the potential to greatly simplify the process, has been introduced in various places. For example, Japanese Patent Application Laid-Open No. 58-15395
7 has been proposed.

This F! According to the 1-hour method, there is no need for the charger, static eliminator, and cleaner processes that are required in conventional xerographic printing methods, and there is no waste toner, resulting in a 10-process simplification. It is possible to reduce the size and cost of the device by reducing the size and toner consumption. This simultaneous method t- To summarize, a bias voltage is applied in the 8 elements and fc4tjt
It is considered that the best developing method is to use a brush of polarized toner to scratch the surface of the image forming body, which originally consists of m-polymers. There is a difference in the amount of charge injected into the toner that is in contact with the surface of the image forming body due to the bias voltage between the exposed part) and the part where 4 acts as a body (exposed part), and the difference in the amount of charge is ii
#7 The difference in electrostatic adhesion to the surface of the image forming body makes it possible to form a toner image.

[Problem that the invention seeks to solve]

However, due to its conductivity, the toner used in the simultaneous method loses the charge injected during image formation in a short time when it comes into contact with transfer paper, weakening its electrostatic adhesion to the paper. The disadvantage of the electrostatic transfer method is that it cannot be transferred to paper in f minutes! Was. Particularly in high humidity, as the resistance value of the paper decreases, the injected charge r;c of the toner is further rapidly lost, and eventually a charge with the opposite polarity to the charge previously M is injected from the paper to the toner. As a result, a so-called blow-off phenomenon occurs in which the toner once transferred to the paper scatters, making transfer practically impossible.

The object of the invention is to provide a printing method using a simultaneous method, which does not have the drawbacks mentioned above. Specifically, the toner 7 provides φ, which enables image formation by a simultaneous method and which can be transferred to plain paper by an electrostatic transfer method even at high humidity.

[Means for solving problems]

In the present invention, the printing system (fit) is carried out by imagewise exposure on both types of formed body comprising a photoconductor layer, and is supplied by a toner supply device consisting of a non-magnetic sleeve containing a magnet when the two types of forming body including the photoconductor layer are opened. A toner pigeon is brought into contact with the image forming body from the side opposite to the image exposure side, and toner tS is selectively applied to the surface of the image forming body by φ acting on the photoconductor layer and the toner j- in an electric field. In a printing device that creates a printed matter by forming a milt layer of C toner and transferring and fixing the toner onto a 1 ml recording medium, the toner is made of steel having a resistivity of 10 $Ω or less. Magnetism'kW
A conductive toner with a resistivity of 10 ΩG or more and an insulating toner with magnetic properties are mixed at a weight mixing ratio of 4'wI.
P3 edge toner α1 to α10 are mixed with V# of L-type toner 1, and fc mixed toner is used. It is characterized by having the same polarity as the charge.

[Effect]

When the toner used in the printing apparatus of the present invention has the above-mentioned configuration, iihIgl, during formation, an image is formed through a stream of conductive toner, which necessarily exists in terms of electrical conductivity, from the toner supply device to the image forming body. A charge corresponding to the accumulation of light is injected into the conductive toner near the surface of the formed body by a developing bias voltage. This difference in the amount of charge injected causes a difference tg in the electrostatic adhesion force of the toner to the surface of the image forming body, and a toner image is formed on the surface of the image forming body using a mixed toner of a conductive toner and an insulating toner. During transfer, an electric field is applied to the conductive toner and insulating toner so that an electrostatic force acts in the direction from the image forming body to the recording medium, so that the toner image is transferred onto the recording medium according to the normal electrostatic transfer principle. It is transferred to 4. At this time, since an insulating toner is used, transferability is ensured even at high temperatures.

〔Example〕

First factor (a), (first of all, an embodiment of the printing apparatus according to the present invention is shown. (a) is an overall view, and (b) is an enlarged view of the main part. A belt-shaped transparent support 1 is A roller 10 rotates an image forming body 4 in the direction of an arrow 5 by a roller 10. A toner supply device 6 supplies conductive toner and insulating toner. The mixed toner 7 is conveyed to the surface of the image forming body 4 by a well-known magnetic brush composed of a magnet roller 8 and a sleeve 9. In particular, it is arranged so that it contacts the image forming body 4 from the side opposite to the aX equipment immediately after the transparent conductor increase 2.
and the developing bias voltage 1 applied between the sleeve 9 and the sleeve 9.
Due to the 30 action, a difference Jl- is generated in the adhesion force to the surface of the image forming member 4 between the g original part and the non-exposed part, and as a result, selective toner adhesion occurs in response to the m light, and an image is formed. m light device 1
1 is a self-focusing rod lens array 14-L C8
1115, a line-shaped source 162 such as a halogen lamp or a fluorescent tube, and this LC
For 8 heads, for example, Japanese Patent Application Laid-Open No. 58-193521
has been disclosed. The image forming body 4 on which the toner image has been formed moves in the direction of arrow 1:D5, and the recording medium 17 is fed by the conveyance roller 18 from the direction of arrow 19, and the recording medium 17 is fed to the well-known direction facing the image forming body 4. The corotron 200 is moving at the same speed as the image forming body 4; during this period, the toner image is electrostatically transferred from the image forming body 4 to the recording medium 17.

The toner image thus formed on the recording medium 17 passes through a well-known thermal fixing roller 21, is sludged and discharged in the direction of an arrow 22. After transfer, image forming body 4
The toner reaches the image forming unit composed of the toner supply device 6 and the optical device 11 again and enters the next printing process, but until this time, the residual toner remaining on the image forming body without being transferred is Then, the hole charge is neutralized according to the relaxation time of the toner and the image forming body, and the electrostatic adhesion force is weakened.
There's nothing left.

FIG. 2 shows details of how an image is formed in the printing apparatus according to the present invention. In the figure, the same elements as in FIG. 1 are labeled with the same symbols. The image forming body 4, which is made up of the transparent support 1, the A8A conductor shield 2, and the photoconductor layer 6 stacked in this order, is moved in the direction of the arrow 5; J dew original 1
27 Receive. A well-known magnetic brush formed using a magnet roller 8 and a sleeve 9 transfers the conductive toner 24.
And insulating toner-25? The mixed toner 7 is in contact with the image forming body 4 at the exposure portion. Since the sleeve 9 is made of a non-magnetic material and a developing bias voltage 15 is applied, the conductive toner in contact with the image forming body 4 is
4′! Charge is injected from the sleeve 9 through seven channels formed by the contact of the toner particles 24 with each other. This current wr changes from time to time according to the mutual positional relationship of the toner particles, which become smaller as the mixed toner 7 moves on the sleeve 9. There are definitely multiple current paths to the toner, and the above-mentioned ammeter pressure injection occurs reliably.

At this time, the charged polarity of the insulating toner 25 is the polarity of the charge injected into the conductive toner 24 during image formation (minus in this embodiment) and the quadrupolar (minus in this embodiment)
Since the insulating toner material is selected so that the electroconductive toner 24 and the insulating toner 25 are electrodynamically repulsive, an electrodynamic repulsive force is generated between the conductive toner 24 and the insulating toner 25, but are both magnetic? ]-! L, because they are in the magnetic field of the magnet 8, they are attracted to each other by 4 m, and when the sexual toner 24 is deposited on the surface of the image forming body 4, the nearby insulating toner 25 also adheres, and is deposited on the image forming body 4. An image is formed using a mixed toner 7 of a conductive toner 24 and an insulating toner 25.

In the Mayu non-g light club, light guide il! Since layer 3 is considered insulating, the charge injected into conductive toner 24 by development bias voltage 13 is small. Furthermore, the insulating toner 25 has an adhesion force to the image forming body 4 due to its pre-existing charge (in this case, a negative charge), but this toner adhesion can be prevented by setting the magnetic attraction force of the magnet 8 to an excessive value. can. Incidentally, the insulating toner 25 is added to the material so as to have a charged charge r with a local polarity due to the heavy electrical connection with the sleeve 9, and is charged in advance during the toner feeding process in the toner supply device 6 and is supplied to the developing section. Ru.

FIG. 3 shows details of how images are transferred by the electrostatic transfer method in the printing apparatus of the present invention.

In the figure, the same elements as in FIG. 1 are labeled with the same symbols.

A recording medium 17 is stacked on the surface of the image forming body 4 on which a toner image has been formed, and an insulating toner 25 and a conductive toner 24 are transferred from the side of the recording medium 17 by a corona transfer device 20.
ft1l! Ions of opposite polarity to the charge (positive ions in this example) are implanted. As a result, an electric field is generated in which an electrostatic force acts on the insulating toner 25 and the conductive toner 24 in the direction from the image forming body 4 toward the recording medium 17, and the toner 1ili image is transferred to the recording medium according to the normal electrostatic transfer principle. 17.

Charge neutralization (leakage) occurs in the conductive toner 24 in the toner image before the conductive toner 24 is transferred to the transfer area, depending on the relaxation time determined by the resistance value and dielectric constant of both the image forming body and the toner 4. Although the amount of charge held by the toner decreases, since magnetic attraction exists between the toner particles due to their magnetism, the insulating toner adheres to and is transferred to the recording medium as it is transferred to the recording medium. Similarly, after transfer, the toner having the same characteristics as the recording medium 17 loses charge to the recording medium 17 and is injected with ion charges supplied from the corotron, so that the attraction force with the recording medium 17 decreases and is further affected by repulsive force, but the above-mentioned insulating properties It is held on the recording medium by magnetic attraction with the toner 25.

The conditions to be satisfied by the mixed toner of the tetraelectric toner and the P3II+ toner used in the present invention will be described below.

During image formation, it is necessary to quickly inject a charge corresponding to j1 into the toner in contact with the image forming body through the toner train from the toner supply device to the image forming body. Therefore, there is an upper limit to the electrical resistance value of conductive toner. Experiments have shown that the resistivity of μ-conductive toner is one order of magnitude lower than that of toner, which is generally referred to as a low-resistivity toner108
It has been confirmed that Ω is the upper limit, and if a 4m toner having a resistivity higher than this was used, no image was formed.

Additionally, during transfer, since the insulating toner in the toner image is electrostatically transferred, the electric resistance value of the frame and the insulating toner must be relatively large. Experiments have confirmed that the lower limit of the resistivity of insulating toner is 10Ω.
When an insulating toner with a smaller resistivity was used, transfer defects occurred when electrically transferring a conductive toner.

Furthermore, regarding the mixing ratio of the four-electrode toner and the insulating toner, what is the mixing ratio of the insulating toner to the conductive toner? If the size is too large, the ratio of the four electric pole toners that come into contact with the image forming body during image formation will decrease, and the probability of the existence of a droplet line of conductive toner from the toner supply device to the forming body will also decrease, making it difficult to form an image. less likely to form. On the contrary, for conductive toner! I! If the mixing ratio of the three-edge toner is too small, the proportion of insulating toner included in the formed toner image will decrease, resulting in fewer violets being electrostatically transferred to the recording medium, making it impossible to obtain an image with the desired density. It disappears. When the mixture ratio of the conductive toner and the insulating toner was varied seven times, various tests were conducted, and it was found that the insulating toner cL1 to 10 was within the permissible range for the conductive toner 1 in terms of the mixture ratio 1 [it].

As is clear from the above explanation, it is necessary that magnetic attraction force acts on the conductive toner and the insulating toner. Also, the toner needs to be subjected to a certain magnetic force toward the toner supply device. Therefore magnetic! A conductive toner having a magnetic tV and an insulating toner having a magnetic tV are used.

Below are typical examples of the composition of the mixed toner used in the embodiments of the printing method of the present invention. show.

〔composition〕

Conductive toner: Resistance IK 10 μm Average particle size 10 μm Maximum magnetization 400 m u/g Insulating toner: Resistivity 10I4Ω Confucian chargeability Glass.

Average particle size: 10 μm Large magnetization: 20 emu/g Weight mixing ratio: 1 part of conductive toner to 2 parts of insulating toner When the mixed toner having the above structure was used, good results were obtained in both image forming properties and transfer properties.

[Effects of the Invention] As described above, the printing apparatus according to the present invention solves the problems caused by the simultaneous printing method by using a mixed toner mixture of a four-electrode toner and an insulating toner. It has improved transferability, making it possible to perform transfers that were previously impossible, especially in times of high humidity. Also,
As a result, it is possible to provide a compact and low-cost printing device 111 whose steps included in a printing cycle are greatly reduced compared to printing devices using conventional xerography technology.

Note that it is not necessary that the coloring agent for visualizing the image be included in both the conductive toner and the insulating toner, but it is sufficient that the coloring agent be included in at least the insulating toner in the printing method of the present invention. It is clear from the principle.

Furthermore, the image forming body used in the present invention is Sea A
It is possible to use either a Fff D belt or a belt without a seam, but if the belt is without a seam, the belt length can be shortened regardless of the printing length, which leads to further downsizing of the apparatus.

Furthermore, the surface of the image forming body is coated with a thin film that has appropriate electrical resistance and mechanical strength, which improves printing durability.
It is effective in improving the stability of image formation.

[Brief explanation of the drawing]

FIG. 1 (aL (1) J is a diagram showing an embodiment of the printing device according to the present invention, FIG. 2 is a diagram showing details of how image formation is performed in the printing device according to the present invention, and FIG. A diagram illustrating details of how the image is transferred by the electrostatic transfer method in the printing device according to the invention. 1...Transparent support 2...Transparent conductor layer 5...Photo 4-electrode, jso 4... Image forming body 6... Toner supply device 7... Mixed toner 8... Magnet roller 9... Sleeve 11... G light device 12... No light 15... Bias voltage 17... d Self-recording medium 18...Conveyance roller 20...Corotron 21...Heat fixing roller 24...*1 toner 25...Insulating toner or above Applicant Seiko Epson Corporation Figure 1

Claims (1)

[Scope of Claims] An image forming body comprising a photoconductor layer is subjected to imagewise exposure, and at approximately the same time as the imagewise exposure, a toner layer is supplied by a toner supplying device comprising a non-magnetic sleeve containing a magnet. is brought into contact with the image forming body from the side opposite to the image exposure side, and an electric field is applied to the photoconductor layer and the toner layer, thereby selectively adhering toner to the surface of the image forming body. In a printing device that forms a toner image and transfers and fixes the toner image onto a recording medium to create a printed matter, the toner includes a conductive toner having magnetism with a resistivity of 10^6 Ωcm or less, and a conductive toner with a resistivity of 10^6 Ωcm or less. A mixed toner is used in which an insulating toner having a magnetic conductivity of 6 Ωcm or more is mixed in a weight mixing ratio of 0.1 to 10 parts of the insulating toner to 1 part of the conductive toner, and further, the friction of the insulating toner is A printing device characterized in that charging polarity is the same as the charge injected into the conductive toner during the image exposure.