JPH04338962A - Electrostatic thermal recording method and electrostatic image carrier - 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.

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. Both patents describe the use of a material that has the property that the electrical resistance of the resin layer (a macromolecular compound) decreases or increases with temperature. JP-A-51-68233, JP-A-52-
No. 19534 discloses a technique in which a thermal signal 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.

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 specifications already filed include a description of using a thermal head for heating, a pre-charged thermal head, or applying a bias voltage to the thermal head, and that the recording layer has slipperiness and is polypropylene or polypropylene-based. It is described that the recording medium is made of a copolymer, a fluorinated acrylic-acrylic copolymer, a perfluoroalkyl acrylate, a silicone polymer, or a mixture thereof. A thermal writing method from the conductive layer side has also been proposed. 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. The prior art does not disclose a specific method such as thermal writing from the conductive layer side, and therefore does not disclose a recording material suitable for that method. Furthermore, although the present inventors have already proposed a thermal writing method from the conductive layer side, disclosure of the specific method and necessary conditions for the recording material was lacking. It has already been proposed that writing and development can be performed simultaneously if thermal writing is performed from the conductive layer side. However, the specific implementation method and materials were not disclosed.

0003

SUMMARY OF THE INVENTION The present invention provides a method for forming an image with excellent image quality using a small device by thermal writing from the conductive layer side of an electrostatic image carrier, and an electrostatic image carrier therefor. This is what we are trying to provide.

[Means for Solving the Problems] The structure of the present invention for solving the above problems is an electrostatic thermal recording method and an electrostatic image carrier as set forth in the claims. In the electrostatic image bearing member of the present invention, the conductive layer preferably consists of an aluminum layer having a thickness of 0.05 μm or more and is preferably 1/10 or less of the thickness of the recording layer. If the thickness of the aluminum conductive layer is less than 0.05 μm, sufficient conductivity will not be obtained and uneven charging will occur, causing uneven printing. If it is thicker than 1/10 of the thickness of the recording layer, heat Because of the diffusion, the printing becomes blurry.

[0004] Hereinafter, the electrostatic thermal recording method using the electrostatic image carrier of the present invention will be explained in detail with reference to the drawings. 1 and 2 illustrate 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. aluminum conductive layer 3
This is to make the charging uniform, but it is not necessarily necessary if this function is achieved by sandwiching it between the conductive members of the counter roller or the 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 there are also methods of applying voltage to a metal roller and methods of frictional charging using rollers with brushes or sponge materials that have various organic or inorganic surfaces. Can 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 (Figure 5) This is the same as powder toner development and liquid toner development performed in normal electrophotography, but it is reversal development. [Development by the repulsion power field of the toner with the same sign (- in the figure) as the charge that remains without a thermal signal (minus charge in the figure)] Transfer process (Figure 6) This process is also performed in the same way as 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, to ensure a good surface for the next image,
Any powder or liquid toner left on the electrostatic thermal recording layer must be removed before reuse. By repeating these steps, digital information can be recorded on plain paper.

[0006]

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples shown in Table 1. When a conductive layer made of Al was provided with different thicknesses on a PET film with a thickness of 25 μm and recorded in the order as explained in the drawing, it was found that the thickness was 0.05 μm.
It was found that Al having a thickness of 1/10 or less of the recording layer thickness is suitable.

[0007]

[Table 1]

[0008]

As described above, according to the present invention, by writing with a thermal head from the conductive layer side, disturbances in the electrostatic latent image can be eliminated. Furthermore, development can be performed simultaneously with writing, and the process steps can be shortened, resulting in smaller and lower costs of the apparatus.

[Brief explanation of drawings]

[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 an electrostatic image carrier having an aluminum conductive layer on the back surface of the recording layer, a latent image is formed on the electrostatic image carrier by heating and partially attenuating the potential depending on the image. An electrostatic thermal recording method in which an image is formed by forming a latent image and a developed image is obtained by developing the latent image, the image being written by a thermal head from the aluminum conductive layer side on the back side of the recording layer. 2. In an electrostatic image carrier comprising an electrostatic thermal recording layer that is chargeable at room temperature and becomes non-chargeable or weakly chargeable under heating, and a conductive layer on the back side, an aluminum conductive layer is used. An electrostatic image carrier having a thickness of 0.05 μm or more and 1/10 or less of the thickness of an electrostatic thermal recording layer.