JPS6310168A - Printing device - Google Patents

Abstract

PURPOSE:To obtain a good electrostatic transfer, and also, to execute a transfer, especially, at the time of high humidity by using a conductive toner containing a (p) type or (n) type semiconductor, as an electric conductor of the toner. CONSTITUTION:A (p) type or (n) type semiconductor is used as an electric conductor 24 of a toner, and one of them is used in accordance with the polarity of a photoconductor layer 3. To a toner 7 being in contact with an image forming body 4, charge corresponding to the polarity of a bias voltage 13 is injected from a sleeve 9, and since the charge injection quantity is different in an exposed part and an unexposed part, a difference is generated in an electrostatic adhesion of the toner, to the surface of the photoconductor layer 3, and an image information is executed. Also, on the surface of the image forming body 4, a recording medium 17 is superposed, the reverse side is electrified to the polarity opposite to the charge which has been injected at the time of forming an image of the toner 7 by a corona transfer device 20, and by an electrostatic force generated between the toner and the charge of the reverse side of the recording medium 17, the toner 7 is transferred onto the recording medium 17 from on the photoconductor layer 3. In this way, even at the time of high humidity, a transfer to usual paper can be executed by an electrostatic transfer method.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a printing device that uses a photoconductor and uses so-called xerography technology, and more specifically, relates to a printing device that uses a toner with a special structure. The present invention relates to a printing device that utilizes new xerographic technology.

[Prior Art] In recent years, various printing devices using xerography technology have been put into practical use and used. To outline the toners used in this technology, in the case of printing devices using the "Carlson process", insulating non-magnetic toner and jumping toner are used in two-component magnetic brush development method and float electrode effect development method (FEED method). In the development method, an insulating magnetic toner is used, and in the case of electrofax, a conductive magnetic toner is used.

Recently, a method using new xerography technology that forms images by simultaneously performing exposure and development (hereinafter referred to as the "simultaneous method") has been studied in various places, which has the potential to greatly simplify the process. For example, JP-A-58-15395
7 has been proposed.

This simultaneous method eliminates the need for chargers, static eliminators, and cleaner processes that are required in printing devices using conventional xerography technology, and also eliminates the generation of toner, which simplifies the process and eliminates toner. This makes it possible to reduce the size and cost of the device. To give an overview of this simultaneous method, a method in which the surface of the image forming body containing the photoconductor layer is rubbed with a brush of conductive magnetic toner to which a bias voltage is applied during exposure is considered to be the optimal development method. , the amount of charge injected into the toner in contact with the surface of the image forming body due to the bias voltage when the photoconductor acts as an insulator (unexposed area) and when it acts as a conductor (N source area) This difference in charge amount results in a difference in the electrostatic adhesion force to the surface of the image forming body, making it possible to form a 1.0-degree image.

[Problems to be solved by the invention] However, due to the conductivity of the toner used in the simultaneous method, the charge on the toner is neutralized in a short relaxation time, and the conductivity of the paper is reduced, especially at high temperatures. As a result, the toner is injected from the paper into the toner, causing problems such as the toner scattering after transfer and disturbing the image, resulting in the disadvantage that a good transferred image cannot be obtained.

The object of the present invention is to provide a printing device using the simultaneous method, which does not have the above-mentioned drawbacks. Specifically, it is an object of the present invention to provide a toner that can form an image in a simultaneous method and can be transferred onto plain paper by an electrostatic transfer method even at high temperatures.

[Means for Solving the Problems] The printing apparatus of the present invention exposes the photoconductor layer to light on the image forming body including the photoconductor layer, and simultaneously or immediately after the exposure, By bringing the toner layer into contact with the image forming body from the opposite side and applying an electric field to the photoconductor layer and the toner layer, the toner is selectively attached to form an image. In a printing device that creates a printed matter by transferring a toner image from an image forming body onto a recording medium, a conductive toner containing a p-type or n-type semiconductor is used as the conductor of the toner, and during development, the toner is It is characterized in that development is performed by charge injection using highly mobile carriers, and during transfer, transfer is performed using an electrostatic electric field with a polarity opposite to that of the highly mobile carriers of the toner.

[Function] When the toner used in the printing apparatus of the present invention has the above configuration, charge injection into the toner that is in contact with the surface of the image forming body during image formation in the simultaneous method is carried out by the semiconductor contained as a conductor. This is done by charge injection due to the movement of highly mobile carriers, and even if the injected charge is neutralized by contact of the toner with the recording medium after electrostatic transfer, the polarity of the transfer electric field remains unchanged between the toner and the toner. By setting the polarity opposite to that of the highly mobile carrier, it is possible to prevent charge from being injected into the toner and scattering of the toner after transfer.

[Example] Figure 1 (ω, (bl) shows an example of the printing apparatus according to the present invention. (a) is an overall view (bl is an enlarged view of the main part. A belt-shaped transparent support An image forming body 4 formed by laminating a transparent conductor layer 2 and a photoconductor layer 3 on a roller 10
is rotating in the direction of arrow 5. 6 is a toner supply device, and toner 7 is supplied to a magnetic roller 8 and a sleeve 9.
The image forming member 4 is conveyed to the surface of the image forming body 4 by a well-known magnetic brush composed of a magnetic brush.

The toner layer thus supplied is arranged to contact the image forming body 4 from the side opposite to the exposure side at the same time or immediately after the exposure 12 by the exposure device 11, and is placed between the transparent conductor layer 2 and the sleeve 9. Due to the action of the bias voltage 13 being applied, there is a difference in the adhesion force to the surface of the image forming body 4 between the exposed area and the non-exposed area, and as a result, selective toner adhesion occurs depending on the exposure, and an image is formed. be done. The exposure device 11 includes a self-focusing rod lens array 14 and an LCS head substrate 15.
- The main component is a linear light source 16 made of a halogen lamp or a fluorescent tube, and this LCS head is disclosed in, for example, Japanese Patent Laid-Open No. 58-193521.

The image forming body 4 on which the toner image has been formed moves in the direction of arrow 5, and the recording medium 17 is moved in the direction of arrow 1 by the conveyance roller 18.
9, the toner image is transferred from the image forming body 4 to the recording medium while moving under the well-known corotron 20 facing the image forming body 4 at the same moving speed as the image forming body 4. 17 by electrostatic transfer. The toner image thus formed on the recording medium 17 passes through a well-known heat fixing roller 21, is fixed, becomes a printed matter, and is discharged in the direction of an arrow 22. After the transfer, the image forming body 4 reaches the image forming unit consisting of the toner supply device 6 and the exposure device 11 again, and enters the next printing process, but the residual material remaining on the image forming body without being transferred is removed. By this time, the toner has been neutralized in accordance with the relaxation time of the toner and the image forming body, and the electrostatic adhesion force has weakened. It turns out that he has no previous history.

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 given the same numbers. An image forming body 4 formed by laminating a transparent support layer 1, a transparent conductor layer 2, and a photoconductor layer 3 in this order receives image exposure 12 as it moves in the direction of an arrow 5.

A well-known magnetic brush formed using a magnet roller 8 and a sleeve 9 causes the toner layer 23 to be in contact with the image forming body 4 at the exposure portion. A bias voltage 13 corresponding to the polarity of the conductor of the toner is applied to the sleeve 9, so that the sleeve 9 charges the toner in contact with the image forming body 4 according to the polarity of the bias voltage. injected into the body. At this time, the amount of charge injected is different between the exposed area and the unexposed area, resulting in a difference in the electrostatic adhesion force of the toner to the surface of the photoconductor layer 3, and image formation is performed.

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 given the same numbers.

A recording medium 17 is placed on the surface of the image forming body 4 on which the toner image has been formed, and the back side of the recording medium 17 is charged by the corona transfer device 2o to a polarity opposite to the charge injected when forming the image of the toner 7. As a result, the toner is transferred from the photoconductor layer onto the recording medium due to the electrostatic force generated between the toner and the charge on the back surface of the recording medium. At this time, the charge of the I-toner that is in electrical contact with the recording medium 17 is neutralized in a short relaxation time, but the charge from the corona charger 20 is made to have the polarity of the low mobility carrier in the conductor of the toner. This can prevent further charge from being injected into the toner and scattering of the toner after transfer.

FIG. 4 shows an example of the structure of the toner used in the printing apparatus of the present invention.
Depending on the polarity of the photoconductor layer 3, one of them is used. 25 is a fine powder of a well-known insulating magnetic material such as Fe3O4 or γ-Fe 203, which is dispersed in the conductor 24. is necessary. As another method of imparting magnetism to the toner, a conductive magnetic material such as iron, cobalt, nickel, etc. can be used for the conductor 24, and is dispersed to an extent that does not impair the semiconductivity of the toner.

[Effects of the Invention] As described above, the printing device according to the present invention uses a conductive toner containing a p-type or n-type semiconductor as a toner conductor in a printing device using a simultaneous method, thereby achieving good results. It is possible to obtain electrostatic transfer that was previously impossible, especially at high temperatures, and the processes included in the printing cycle are greatly reduced compared to printing devices that use conventional xerography technology. It is possible to provide a small, low-cost printing device with a reduced number of printers.

Note that the image forming body used in the printing apparatus of the present invention can be used with a belt with a seam or a belt without a seam, but if the belt is without a seam, the belt circumference can be shortened regardless of the printing length, so the apparatus will be more efficient. Leads to downsizing.

[Brief explanation of the drawing]

FIG. 1 (ml, (b) is a diagram showing an embodiment of the printing device according to the present invention, FIG. 2 is a diagram showing details of image formation in the printing device according to the present invention, and FIG. 3 is a diagram showing the embodiment of the printing device according to the present invention. FIG. 4 is a diagram showing an example of the structure of toner used in the printing device of the present invention. 1-Transparent support 12-N light 2-Transparent conductor Layer 13 - Bias voltage 3 - Photoconductor layer 17 - Recording medium 4 - Image forming body 20 - Corotron 6 - Toner supply device 24 - Conductor 7 - Toner 25 - Insulating magnetic material 11 - Exposure device Applicant: Seiko Epson Co., Ltd. 4 Fig. 1 1 Transparent clear pattern l Fig. 2 Fig. 4

Claims (1)

[Claims] On an image forming body comprising a photoconductor layer, the photoconductor layer is exposed to light, and simultaneously or immediately after the exposure, a toner layer is brought into contact with the image forming body from the side opposite to the exposed side, and By applying an electric field to the photoconductor layer and the toner layer, toner is selectively attached to form an image, and the toner image is transferred from the image forming body onto a recording medium to create a printed matter. In the printing device, a conductive toner containing a p-type or n-type semiconductor is used as the conductor of the toner, and during development, development is performed by charge injection by highly mobile carriers of the toner, and during transfer, the toner is A printing device characterized by performing transfer using an electrostatic electric field with a polarity opposite to that of a highly mobile carrier.