JPH04268562A - Electrostatic thermal recording method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention uses a dielectric material as an electrostatic image carrier (
The present invention relates to a transfer type thermal recording method (electrothermography) in which a latent image is formed by heating (hereinafter also referred to as a latent image medium or a recording medium) and a recording medium used therein. It also relates to printers, faxes, and digital copiers.

0002

2. Description of the Related Art There is a method in which a resin layer whose electrical resistance decreases with temperature by heating is provided on an electrically conductive substrate, and this layer is electrostatically charged and visualized by applying heat through infrared irradiation. Publication 35-14722, Special Publication 37-1587
8, known as Special Publication No. 38-14347. It has been described that these utilize a material in which the electrical resistance of a resin layer (a macromolecular compound) decreases or increases with temperature. JP-A-51-68233, JP-A-52-1
No. 9534 discloses a technique in which a thermal signal provided is used in place of a thermal head. However, there is a lack of disclosure of specific technical means, and in order to put it into practical use, many related technical inventions are required.In fact, image forming devices that form electrostatic latent images by heating have not yet been commercialized. It has not been.

[0003] On the other hand, there are many products of image forming apparatuses employing an electrophotographic method. However, in the electrophotographic method, there are problems due to the photoreceptor. One is the increased cost due to the production of the photoreceptor, and the other is the increased cost because the photoreceptor must have light-shielding properties as part of the device configuration. In addition, the optical unit has a large amount of space,
There are issues such as restrictions on the irradiation direction, which inhibits the degree of freedom in mechanical configuration. The previously filed specifications include a description of using a thermal head for heating and applying a bias voltage to a pre-charged thermal head or a thermal head;
It is described that the recording layer has lubricity and is a recording medium made of polypropylene, a polypropylene copolymer, a fluorinated acrylic-acrylic copolymer, perfluoroalkyl acrylate, a silicone polymer, or a mixture thereof. There is. It has also been proposed to reduce the coefficient of friction by using a lubricant or the like on the surface of the recording layer. Furthermore, the properties of the dielectric material that is the resin layer include that the glass transition temperature of the material is higher than the operating environment temperature, that its thermal deformation temperature is higher than the glass transition temperature, and that the thermal deformation temperature is higher than the thermal writing temperature. is listed.

0004

SUMMARY OF THE INVENTION The present invention aims to prevent disturbance of an electrostatic latent image due to poor lubricity during thermal writing, particularly to prevent streak-like stains due to poor lubricity.

[Means for Solving the Problems] The structure of the present invention for solving the above problems is to charge an electrostatic image carrier and then heat it according to the image using a thermal head to partially attenuate the potential. In an image forming method in which a latent image is formed on an electrostatic image carrier by applying a liquid to the electrostatic image carrier and a developed image is obtained by developing this latent image, the surface in contact with the electrostatic image carrier is formed of a material with good slippage. It is an electrostatic thermal recording method using a thermal head,
In particular, this is an electrostatic recording method that uses a fluorine-based polymer or a silicone-based polymer material as a slippery material. The electrostatic thermal recording method of the present invention will be specifically explained with reference to the drawings. FIGS. 1 and 2 show the electrostatic medium of the present invention. FIG. 1 consists of an electrostatic thermal recording layer 2, a base layer 1, and an aluminum conductive layer 3. The electrostatic thermal recording layer 2 is a resin layer. The base layer 1 is a support member for the electrostatic thermal recording layer 2, and is made of a film-forming material and may also serve as the electrostatic thermal recording layer 2.

[0005] The aluminum conductive layer 3 is used to make charging uniform, but it is not necessarily necessary when this function is achieved by sandwiching it between the conductive members of a counter roller or a counter plate. As the material of the conductive layer, an Al vapor deposited layer and various conductive treatment agents are used. It can also be constructed from a metal drum or belt. The basic structure of the transfer electrostatic recording method of the present invention will be explained with reference to FIGS. 3 to 7. Charging process (Figure 3) The method using corona discharge provides the most uniform charging, but
A method of applying a voltage to a metal roller or a method of frictional charging using a roller having a brush or sponge material having various organic or inorganic surfaces may also be used. Heating process using thermal signals (Figure 4)

In conventional thermoelectrostatic recording, the original and the recording medium are overlapped, and the absorption and heat generation of the black portion by irradiation is utilized (
(analog signal), but in this recording, heating is performed using a digital signal from a thermal head. Thermal head is 8dot/mm~1
A serial head or line head with a high resolution of 6 dots/mm is used. Developing process (FIG. 5) This is the same as powder toner development and liquid toner development performed in normal electrophotography, but it is a reversal development. [Development by the repulsion power field of the toner with the same sign (- in the figure) as the charge remaining without a thermal signal (minus charge in the figure)] Transfer process (Figure 6
) This process is performed in the same way as in electrophotography. In the case of powder toner, it is heated and fixed using a heated roller after transfer. In the case of liquid toner, it is only necessary to dry the remaining liquid. Cleaning process (Figure 7)

After transfer, any remaining powder or liquid toner on the electrothermal recording layer must be removed before reuse to ensure a good surface for the next image. By repeating these steps, digital information can be recorded on plain paper. In electrostatic thermal recording, when thermal writing is performed on a recording layer from a thermal head, if the surface of the thermal head does not have good slipperiness, the electrostatic latent image on the recording layer will be disturbed. We solved this problem by using a material with good slipperiness as the surface layer of the thermal head. As the surface layer material of these thermal heads, fluorine-based polymers such as perfluoroalkyl acrylate and fluorinated alkyl-acrylic copolymers or silicone-based polymers can be used. Fluoropolymer materials showed particularly remarkable effects.

[0008]

[Examples] The present invention will be specifically explained below with reference to Examples. In addition, all the amounts of each component described in the examples are based on weight. Example 1 Fluorine resin paint (Lumiflon, Asahi Glass Co., Ltd.)
(manufactured by) 100 parts xylene

80 parts n-butanol

80 parts hardening agent (butylated melamine)
20 parts of the liquid mixture having the above composition was spray coated on the surface of the thermal head. The recording layer made of PET with a thickness of 25 μm has a minus 70
After charging to 0 V, thermal writing was performed using the thermal head, and development was performed. Clear printing was achieved without any streak-like stains due to disturbance of the latent image.

Example 2 Silicone resin (KR311, manufactured by Shin-Etsu Silicone) 100 parts Mica powder

Part 15 Titanium White

40 parts xylene


After mixing and dispersing all the ingredients consisting of 10 parts with three rolls, it is applied to the surface of the thermal head to form a coating film.
It was dried at 0° C. for 20 minutes to form a surface layer on the thermal head. When an image was formed using this thermal head in the same manner as in Example 1, clear printing was possible without streak-like stains. Comparative Example When recording was carried out in the same manner as in the above example using a thermal head having a surface of TaN without surface treatment, the slipperiness was poor and streak-like scumming occurred due to disturbance of the latent image.

0010

As explained above, according to the present invention, the surface of the thermal head is made slippery, thereby making contact with the recording layer smooth and preventing streak-like stains due to latent image disturbance.

[Brief explanation of the drawing]

[Figure 1]

FIG. 2 is a schematic cross-sectional view showing the structure of the electrostatic image carrier of the present invention;

[Figure 3]

[Figure 4]

[Figure 5]

[Figure 6]

FIG. 7 is an explanatory diagram of steps when implementing the method of the present invention.

[Explanation of symbols]

1 Base layer 2 Electrostatic thermal recording layer 3 Aluminum conductive layer 4 - Corona charging device 5 Thermal head 6 Toner 7 Paper 12 + Corona charging device 14 Initialization device

Claims (2)

[Claims] 1. After charging the electrostatic image carrier, it is heated according to the image using a thermal head, and the potential is partially attenuated to form a latent image on the electrostatic image carrier,
In an image forming method for developing this latent image to obtain a developed image,
An electrostatic thermal recording method characterized by using a thermal head whose surface in contact with an electrostatic image carrier is made of a slippery material. 2. The electrostatic image carrier according to claim 1, wherein the slippery material is a fluorine-based polymer or a silicone-based polymer material.