JPS6290686A - Device and method for printing - Google Patents

Abstract

PURPOSE:To realize a high-reliability, small-sized, and inexpensive printing device which obtains images of high picture quality with high density by using a microcapsule toner for a developer and applying pressure thereto, and transferring a toner image from a photosensitive body to recording paper and fixing the image. CONSTITUTION:A photosensitive body 1 is charged electrostatically by an electrostatic charger 2, image exposure is carried out by an exposing device 3, and the light irradiated part is discharged electrostatically and selectively to form a latent image on the photosensitive body 1. This latent image is developed into a visible image by sticking microcapsule toner 5 which is charged electrostatically by a developing device 4 selectively according to the latent image. At this point of time, the capsule toner 5 sticks on the photosensitive body 1 electrostatically. Then, a form is fed from a paper feeding part at transfer timing and pressed against the photosensitive body 1 by a transfer roller 6. The capsule toner 5 pressed between the paper and photosensitive body has capsules destroyed and liquid ink flows out and is absorbed by the recording paper. The liquid ink is absorbed by the paper immediately, so there is no deficiency in image density due to low transfer efficiency like powder toner transfer and the density of the image is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electrophotographic printing apparatus and a printing method thereof.

[Conventional technology]

Conventional electrophotographic printing devices generally charge a photoreceptor and then expose it to image light to form an electrostatic latent image, and a developing device uses toner charged according to the potential of this electrostatic latent image. Copies are obtained by developing the toner and then transferring and fixing the toner onto transfer paper. A powder whose main component is a thermoplastic resin is used for the developer, and OaS, amorphous Sθ, OPC, etc. are used for the photoreceptor.

Further, an electrostatic transfer method is used for transferring, in which toner is attracted by electrostatic force, and a heat fixing method is mainly used for fixing, in which the toner is welded and fixed on the paper.

[Problem that the invention seeks to solve]

However, in the above-mentioned conventional technology, since toner is transferred electrostatically, 10 to 30% of the toner remains on the photoreceptor without being transferred, resulting in a low density image. Additionally, during the cleaning process to remove residual toner from the photoreceptor, toner leaks outside the cleaner and floats inside the device, contaminating elements that should not be contaminated, such as the charger, resulting in performance deterioration and image stains. has. A heat fixing method is generally used for fixing, but since the toner has the property of melting at high temperatures, there is a problem that when the environmental temperature is high, some of the toner softens and becomes fixed and agglomerated during storage. Another problem is that it takes time for the temperature of the fixing device to reach a predetermined value, and that electric power is required to maintain the fixing device at a predetermined temperature. In addition, there are many process components, which causes the equipment to become larger and more expensive. SUMMARY OF THE INVENTION The present invention aims to solve these problems, and its purpose is to realize a highly reliable, compact, and low-cost printing device that can produce high-density, high-quality images.

[Means to solve the problem]

The printing device of the present invention uses a microcapsule toner as a developer in which liquid ink obtained by dissolving or dispersing dyes and pigments in a medium is encapsulated in microcapsules, and applies pressure to the microcapsule toner to form a toner on a photoreceptor. It is characterized by transferring and fixing images onto recording paper.

[Effect]

According to the above structure of the present invention, the electrostatic latent image on the photoreceptor is made visible by the charged microcapsules, and the microcapsules are destroyed by pressing through the recording paper placed facing the photoreceptor. The liquid ink inside the capsule is then absorbed by the recording paper to form a visible image on the paper.

[Embodiment 1] FIG. 1 is a sectional view of a printing apparatus in an embodiment of the present invention. A microcapsule toner 11 in which a liquid ink 10 made by dissolving or dispersing a dye or pigment as a coloring material in water or other liquid is encapsulated in microcapsules 9 is used as a developer, and the microcapsule toner is transferred by applying pressure.・
It is characterized by simultaneous fixing. The photoreceptor 1 is charged by a charger 2, imagewise exposed by an exposure device 5, and the light irradiated area is selectively relaxed to form a latent image on the photoreceptor 1. This latent image is developed into a visible image by selectively adhering microcapsule toner charged by the developing device 4 according to the latent image. At this point, the microcapsule toner 5 is electrostatically attached to the photoreceptor 1. Next, a sheet of paper is fed from the sheet feeding section in accordance with the transfer timing, and is pressed against the photoreceptor 1 by the transfer roller 6. When the microcapsule toner is pressurized between the paper and the photoreceptor, the capsule is destroyed and the liquid ink flows out from inside and is absorbed by the recording paper. Since the liquid ink is immediately absorbed by the paper, it is possible to achieve high image density without causing insufficient image density due to low transfer efficiency, unlike in the case of powder toner transfer.

On the other hand, the capsule shell remains attached to the photoreceptor due to its electrical charge. Microcapsule shell 7 attached to photoreceptor
is removed from the photoreceptor by the cleaner 8. At this time, the shells of the microcapsules become highly humid due to the destroyed toner, and stay inside the cleaner instead of floating inside the machine like dry powder toner. Microcapsule liquid ink soaks into the paper and does not need to be fixed. Therefore, the two processes of transfer and fixing in a conventional printing apparatus can be performed simultaneously by using microcapsules, and the apparatus can be made smaller. Furthermore, since there is no need to use a thermoplastic resin in the microcapsules, the problem of sticking and aggregation due to temperature rise during storage does not occur. Further, due to the electrification in the developing device, there is no possibility of softening and agglomeration due to frictional heat caused by stirring. The size of the microcapsule toner 11 is suitably 5 to 100 μm in diameter, but preferably 10 μm.
That's about it. Further, since the transfer roller 6 is brought into direct pressure contact with the photoreceptor 1, it is necessary to select a photoreceptor with high hardness to prevent deformation and performance deterioration due to pressure. In this embodiment, amorphous silicon is used as the photoreceptor.

The Vickers hardness of the commonly used photoreceptor OPO is about 25 degrees, and the edge pressure is 4 with a pressure of several hundred to several volts, whereas the Vickers hardness of amorphous silicon is extremely high at 1200 to 1800 degrees. to high<20//cr
Even under pressure of about n, it does not cause ulcers and performance deterioration does not occur. The breaking strength of the microcapsules can be adjusted by adjusting the shell material, shell thickness, and microcapsule diameter. In this example, the breaking strength of the microcapsule toner is set so that it can be completely destroyed by a pressure of 18 Kp/cIn. Microcapsule toner can be destroyed without damaging it.

〔Effect of the invention〕

As described above, according to the present invention, by using a microcapsule toner in which liquid ink is encapsulated in microcapsules as a developer, transfer and fixing can be performed simultaneously. By using liquid ink, it is possible to achieve high density images. Also, unlike the heat fixing method, there is no need to use a thermoplastic resin, so there is no aggregation of the image during storage.
High reliability is achieved, and since transfer and fixing are performed simultaneously, the device can be made smaller and lower in price.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the printing apparatus of the present invention, and FIG. 2 is a sectional view of μ capsule toner used in the printing apparatus of the invention. 1...Photoreceptor 5...Microcapsule toner 6...
Transfer roller 10...Liquid ink or more

Claims (3)

[Claims] (1) In an electrophotographic printing device, a microcapsule toner in which liquid ink is encapsulated in microcapsules is used as a developer to develop an electrostatic latent image on a photoreceptor, and the image is placed opposite the photoreceptor carrying the toner image. It has a pressure applying means for pressing the photoreceptor through the arranged recording paper, and the pressure applying means destroys the microcapsule toner on the photoreceptor and absorbs the liquid ink inside the microcapsule onto the recording paper. A printing device configured to form an image on recording paper by (2) The printing apparatus according to claim 1, wherein the photoreceptor is made of an amorphous silicon photoconductive layer. (3) In an electrophotographic printing device, a microcapsule toner in which liquid ink is encapsulated in microcapsules is used as a developer to develop an electrostatic latent image on a photoconductor, and a record is placed facing the photoconductor. A printing method comprising: applying pressure to the microcapsule toner through paper to destroy it, and absorbing liquid ink inside the microcapsules onto the recording paper to form an image on the recording paper.