JP3129813B2 - Recording device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording medium in which a region showing a receding contact angle corresponding to a heating temperature is selectively or reversibly formed on the surface of a recording medium, and the region contains a developer. The present invention relates to a recording apparatus that forms a visible image by contacting an agent.

[0002]

2. Description of the Related Art A conventional recording apparatus is disclosed in
There is one disclosed in Japanese Patent No. 5185. this is,
By selectively heating the surface of the recording body in contact with the contact material, or by contacting the surface of the recording body with the contact material while selectively heating, the surface of the recording body is heated to the heating temperature. There are provided means for applying the contact material for forming a latent image area having a corresponding receding contact angle to the surface of the recording medium to a uniform thickness, and means for heating the surface of the recording medium through the contact material. The contact material has the function of a recording agent.

In this recording apparatus, the means for heating the surface of the recording body, that is, the heating element for thermal recording is, for example, 300 dpi, the length Lx in the x direction is 70 μm, and the length in the y direction is 70 μm, as shown in FIG. The heating elements 20 are rectangular in shape with a length Ly of 110 μm, and the heating elements 20 are arranged in parallel with a gap d of 15 μm. It is. However, in such a standard heating element shape, the temperature difference between the heating element 20 and the gap d is large, which causes white stripes. Therefore, various measures have been taken to make the temperature distribution between the adjacent heating elements 20 uniform, such as by providing slits in this rectangle, changing the electrode extraction method, and forming a meandering shape.

FIG. 7 shows a model of the temperature distribution and the receding contact angle change of the heating element 20. The receding contact angle of the area where the heating element is heated to a predetermined temperature, for example, 80.degree. For example, the temperature is reduced to 25 degrees, so that ink is to be attached to a region substantially the same as the shape of the heating element.
In this case, it is necessary that the temperature distribution of the shape of the heating element matches the temperature distribution of the recording medium.

[0005]

However, as shown in FIG. 8, the temperature distribution of the heating element 20 in the conventional recording apparatus is 80.degree. C. to 100.degree. C. compared to the ideal temperature distribution (see FIG. 7). The portion of ° C. protrudes, and the ink also adheres to the protruding portion (the hatched portion is the development region), so that it becomes difficult to adhere the ink to the area of the recording paper that faithfully corresponds to the shape of the heating element. For this reason, the SN ratio of the receding contact angle in the area of the gap d becomes worse,
There is a problem that mutual interference between adjacent dots during development is increased.

[0006] Such deterioration of the SN ratio of the gap portion increases as the shape of the heating element increases as Lx <Ly. Therefore, by lowering the temperature by lowering the overall applied voltage, the deterioration of the S / N ratio in the gap portion is improved, but the heat generation region above the threshold temperature required for ink adhesion is reduced, and the transfer to the recording paper is rather performed. There is a problem that dots sometimes do not connect on the recording paper and cause white stripes.

Therefore, the present invention solves the above-mentioned conventional problems, reduces the temperature difference in the gap between adjacent heating elements, provides a good SN ratio of the receding contact angle in this gap, and improves the It is an object of the present invention to provide a recording apparatus capable of preventing white streaks from occurring.

[0008]

Means for Solving the Problems The present invention, in a state where the surface of serial Rokutai contact with the solid to be liquid by the liquid or vapor or heated, is heated by the heating element, to increase the heating
Forming a smaller receding contact angle in accordance with that temperature, after development by contacting the recording agent containing a developer to the superheating unit, transfers the visible image onto a recording sheet, or the receding contact simultaneously it makes a corner by contacting the pre-crisis recording agent and a latent image formed after developing and the same time, in a recording apparatus for transferring the visible image onto a recording sheet, the shape of the heating element,
The length Lx of the direction of the adjacent heating element (x direction) and the length Ly of the direction perpendicular to the direction (y direction) satisfy the relationship of Lx> Ly, and the basic pixel of the visible image is There is provided heating means for forming the heating element by heating the heating element in parallel in the y-direction sequentially and a plurality of times.

[0009]

Therefore, the recording body is heated by the heating element to form a receding contact angle corresponding to the heating temperature (formation of a latent image).
In this case, the basic pixels are formed by heating a plurality of times sequentially in parallel in the y direction by a heating unit. As a result, the temperature distribution in the basic pixel approaches the ideal temperature distribution, so that development without mutual interference with the adjacent heating element is performed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. In FIG. 1, a latent image forming liquid 2 and a thermal head 3 (a part of a heating unit) having a heating element at a front end portion are included in the vicinity of a recording medium 1 supported by supporting rollers 11a and 11b. Latent image forming section 4, developer 5 as recording agent
, A transfer roller 8 for pressing the recording medium 1 through the recording paper 7, a cleaning unit 9 for removing the residual developing solution on the recording medium 1, an image removing unit 10 for erasing a latent image after cleaning, and the like. Is arranged.

The recording apparatus shown in FIG. 2 is substantially the same as the recording apparatus shown in FIG. 1, and the same members are denoted by the same reference numerals. That is, the developing unit 12 is arranged together with the developing unit 6. The developing section 12 has a thermal head 3 and a developer 5.

By the way, the recording medium 1 and the developing solution 5 in the embodiment shown in FIG. 1 and FIG.
The pitch of the thermal element shape of the thermal head 3 is 8 dots / m.
m, as shown in FIG. 3, the shape of the heating element 15 is such that the length Lx in the direction of the adjacent heating element 15, that is, in the x direction is 100 μm.
m, the length Ly in the direction orthogonal to the x direction is 30 μm, and Lx> Ly (the conventional heating element shape is Lx <Ly, indicated by a broken line), and the adjacent heating element The gap between 15 is d. However, the lengths of Lx and the gap d for a resolution of 300 dpi are the same as in FIG.

In the printing apparatus having the above structure, the heating means is driven by setting the moving speed of the printing medium 1 to 10 mm / S and the driving frequency of the thermal head 3 in the sub-scanning direction to 333 Hz. As shown in FIG. The heating in the sub-scanning direction was performed five times on the basic pixel per dot, that is, five times in parallel in the y direction. By this heating, the shape of the basic pixel per dot is Lx = 100 μ
m, Ly = 150 μm. In this case, the temperature distribution of the heating element 15 at 80 ° C. is, as shown in FIG.
In the heating element 15 having a relation of> Ly, the deviation from the ideal temperature distribution is small in the x direction and large in the y direction (A is an 80 ° C. line and the hatched portion is a development region), as shown in FIG. When the basic pixel shape per dot is formed by heating a plurality of times, the gap d and the heating element 1 are formed.
The temperature difference with the 5 parts approaches the ideal temperature distribution. The latent image thus formed was sharp, and the developer 5 easily passed between the latent images.

Here, for comparison, as in the prior art, the latent image was formed by driving the heating element only once with respect to the basic pixel per dot, with Lx = 100 μm. As a result, the latent image had an elliptical shape with a short diameter of 110 μm and a long diameter of 150 μm, the shape was not sharp, the developer 5 was hard to pass between the latent images, and the background was stained.

As described above, by adopting the shape of the heating element 15 of this embodiment, the temperature difference between the heating element 15 and the gap d is reduced, and the SN ratio of the receding contact angle in the gap region is improved. .

[0016]

As described above, according to the present invention,
The shape of the heating element is set such that the length Lx in the direction of the adjacent heating element and the length Ly in the direction perpendicular thereto are Lx> Ly, and a basic pixel (dot) is moved in the y direction. Since it is formed by heating a plurality of times in parallel, the temperature difference between the heating element and the gap portion is reduced, the mutual interference between adjacent dots during development is suppressed, and the occurrence of white stripes can be prevented. .

Also, since the area where the ink adheres to the recording paper in the adjacent dots can be provided close to each other, there is an effect that the gap portion is filled with the ink by a slight diffusion of the ink when the ink is transferred to the recording paper. .

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a recording apparatus according to the present invention.

FIG. 2 is a schematic configuration diagram showing an embodiment of a recording apparatus according to the present invention.

FIG. 3 is an explanatory view showing a shape of a heating element of the present invention.

FIG. 4 is an explanatory diagram showing a method of forming a basic pixel per dot.

FIG. 5 is an explanatory diagram showing a temperature distribution of a heating element.

FIG. 6 is an explanatory view showing the shape of a conventional heating element.

FIG. 7 is a characteristic diagram showing an ideal temperature distribution and a change in receding contact angle of a conventional heating element.

FIG. 8 is an explanatory diagram showing a temperature distribution and a development area of a conventional heating element.

[Explanation of symbols]

 Reference Signs List 1 recording medium 5 recording agent 7 recording paper 15 heating element 16 basic pixel

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-3-178479 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) B41L 19/00-19/06 B41C 1 / 00-1/16 B41M 5/00-5/26

Claims (1)

(57) [Claims] A recording medium is heated by a heating element in a state in which the surface of the recording medium is in contact with a liquid, a vapor, or a solid which becomes liquid by heating, and the surface of the recording medium is reduced in accordance with the temperature which is increased by the heating. forming a contact angle, after developing by contacting a recording agent containing a developer to the superheating unit, transfers the visible image onto a recording sheet, or by forming the said receding contact angle at the same time,
After pre-crisis book agent contacting the developer and the latent image formed at the same time, in a recording apparatus for transferring the visible image onto a recording sheet, the shape of the heating element is adjacent the heating element direction (x-direction) Lx and the length Ly in the direction perpendicular to the direction (y direction) are Lx
> Ly, and heating means for forming the basic pixels of the visible image by heating the heating element in parallel in the y-direction a plurality of times sequentially. Recording device.