JPS63254067A - Recording head - Google Patents

Abstract

PURPOSE:To obtain a recording generating no tailing, by providing a heat generator selectively generating heat in accordance with an image signal, a spacer holding the heat generator and a recording medium to a non-contact state and a temp. gradient part for cooling a recording dot. CONSTITUTION:When a voltage pulse is applied to a heat generator 7, the heat generator selectively generates heat and the ink 3 therearound is melted to be lowered in its viscosity. Then, the ink 3 begins to flow out from an ink passing hole 8 to spread in a space 13. The molten ink 3 fully spreads then in the region where the heat generator 7 is present. At this time, the generation of the heat from the heat generator 7 stops and, at the same time, the radiation of heat begins and the viscosity of the ink 3 increases to stop the outflow of the ink 3. Next, the ink layer is separated into the layer covering the heat generator 7 and the layer transferred to recording paper 10 with the movement of the recording paper 10 to form a recording dot 12 on the recording paper 10 and the state of the heat generator 7 returns to the initial state. In the above-mentioned process, by providing a cooling part 14 on the downstream side of the heat generator 7 with respect to the recording paper 10, a heat radiation property becomes good and the viscosity increasing time of the ink 3 becomes fast.

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a recording gutter used for example in printers, electronic typewriters 1, facsimile machines, electronic whiteboards, various bulletin boards, and the like.

<Prior Art> In recent years, with the development of information technology, various information processing systems have been developed, and recording devices suitable for each information processing system have been developed.

One of the above-mentioned recording devices is a thermal transfer recording device. In this method, recording is performed on recording paper using an ink film formed by applying heat-melting ink to a support.

That is, the ink films are stacked so that the heat-melting ink layer is in contact with the recording paper, and the ink is transferred onto the recording paper by applying pulse-like heat according to the image signal from the support side of the ink film using a recording head. It forms a recorded image.

<Problems to be Solved by the Invention> The recording device using the above-mentioned ink film requires the installation of an ink film feeding mechanism, and furthermore, since the ink film is a consumable item, there are other problems such as high running costs. There is.

<Means for solving the problem> In order to solve the above-mentioned problem, this type of recording gutter, which performs direct thermal recording without using an ink film, is shown in Figures 5 (A) and (B). As shown, a housing 2 capable of storing ink 3 is provided on one side of the substrate 4, and a heating element 7 that selectively generates heat according to image signals is provided on the other side.
, an ink passage hole 8 penetrating the heating element 7 and a spacer (
The applicant has already proposed a device equipped with a window or spacer (9) (Japanese Patent Application No. 1108/1986).
56).

The present invention further develops the above-mentioned technology, and its means includes: an insulating substrate having an ink passage hole; a housing provided on one surface of the insulating substrate for storing ink; A heating element provided on the other surface and selectively generating heat according to an image signal; a spacer provided on or near the heating element to maintain the heating element and the recording medium in a non-contact state; and a dot forming area. It is characterized by having a temperature gradient section for cooling the recording dots inside.

<Function> By having a temperature gradient in the dot formation area, the temperature of the recording dots that flowed out from the ink passage holes and were transferred onto the recording medium decreases quickly as the recording medium advances, and therefore the flowed out ink is continuously transferred. It has a very high viscosity and forms sharp recording dots.

<Example> FIG. 1 is a schematic sectional view of a recording method, and the second part is an external view of a multi-type recording head in which the recording parts of the recording head are arrayed in a line.

In the figure, ■ is a recording head, which houses a so-called heat-melting (including softening and sublimation) ink 3 that maintains a high viscosity at room temperature but decreases in viscosity at high temperatures inside a housing 2. It looks like this.

A ceramic base 4 made of alumina, zirconia, etc. is provided in a part of the housing 2 via a reinforcing plate 5 made of stainless steel, iron plate, copper plate, etc.

On the other surface of the substrate 4, an electrode 6 and a heating element 7 made of ruthenium oxide are provided at the end of the substrate 4.
As shown in FIG. 2, a plurality of ink inks are arranged in an array with one square pitch, and an ink passage hole 8 with a width of 0.2 m is provided at the position of each heating element 7. Further, each heating element 7 is configured to generate heat individually by selectively applying a voltage to the electrode 6 according to an image signal from a control section (not shown).

To perform the recording using the recording gutter 1, as shown in FIG. 1, the spacer 9 is brought into contact with the recording paper IO as a recording medium,
A predetermined image is recorded using recording dots 12 while conveying the recording paper 10 by a platen roller 11 rotated in the direction of arrow a by a drive device (not shown).

Next, a case in which recording is performed using the recording head I will be specifically explained.

First, when a voltage pulse corresponding to an image signal is applied to the heating element 7 through the electrode 6, the heating element 7 selectively generates heat, and the ink 3 near the heating element 7 is heated. This ink 3 has a high viscosity at room temperature and therefore does not pass through the ink passage hole 8, but when heated as described above, the viscosity decreases and it passes through the ink passage hole 8.

As described above, the ink 3 that has passed through the ink passage hole 8 is transferred to the space formed by the heating element 7 and the spacer 9 and to the recording paper 10.
It spreads between. At this time, while the recording paper lO is conveyed by the platen roller 11, the ink 3 is simultaneously transferred to record the recording dots 2. Note that it is preferable to apply a static pressure higher than the outside air pressure (about 0.1 atmosphere gauge pressure) inside the housing 2 because this will promote the passage of the ink 3.

By repeating the above process according to both signals, the recording paper 1
Recording dots 12 are continuously formed on the recording medium 0, and a recorded image is transferred thereto.

Next, the recording process using the above recording head will be explained with reference to FIG.

(A) shows the initial state, in which the ink 3 fills the inside of the housing 2 and the inside of the ink passage hole 8, and also covers the heating element 7. However, the space 1 formed by the spacer 9
3, the ink 3 on the heating element 7 is kept in a non-contact state with the recording medium 10. Also at this time, ink 3
Since the ink maintains a high viscosity, it cannot pass through the ink passage hole 8.

Here, when a voltage pulse is applied to the heating element 7 corresponding to the image signal through the electrode 6, the heating element selectively generates heat (15
(0°C or higher), which melts the surrounding ink and lowers its viscosity. Then, as shown in (B), the ink passage hole 8
The ink 3 begins to flow out from there, and the ink 3 spreads within the space 13 between the heating element 7 and the recording paper 10.

Eventually, as shown in (C), the melted ink 3 spreads to the entire area where the heating element 7 is present. At this time, the heat generation of the heating element 7 ends, and at the same time, heat radiation begins. Along with the heat radiation, the ink 3 becomes highly viscous again, so that the ink 3 stops flowing out.

Next, as shown in (D), as the recording paper 10 moves, the ink layer is separated into a layer covering the heating element 7 and a layer transferred onto the recording paper 10. Then, a recording dot 12 is placed on the recording paper lO.
is formed, and at the same time, the state of the heating element 7 returns to the initial state of (A).

In the above process, by providing a cooling section 14, which will be described later, on the downstream side of the heating element 7 with respect to the recording paper 10 in steps (C) and (D), heat dissipation is improved and the ink 3 is heated. The time it takes for the viscosity to increase becomes faster. Therefore, the ink 3 can be easily cut, and recording marks 2 without trailing can be formed.

Next, the structure of the heat generating section of the recording head I having the cooling section 14 as described above will be shown with reference to FIG.

In FIG. 4, 6 is a TL pole, 7 is a heating element, 8 is an ink passage hole, and 14 is a cooling section. Further, 15 is a dot forming area. Furthermore, the arrow indicates the direction in which the recording paper 10 travels. (In the following explanation, upstream or downstream refers to the traveling direction of the recording paper IO.) In (A), the dot formation area 15 has a heating element in approximately half of the upstream side with respect to the recording paper IO. 7, and a cooling section 14 is formed approximately in the downstream half.

Here, the cooling section 14 will be explained in detail.

The member of the additional part 14 is preferably made of a material with high thermal conductivity, such as metals such as copper, iron, or aluminum, alloys thereof, or ceramics such as A4N. Furthermore, any resin such as polyimide may be used as long as it has a temperature lower than that required for forming dots on the downstream side of the dot forming region during dot formation.

Therefore, any configuration that creates a temperature gradient in the dot forming area with respect to the traveling direction of the recording paper IO may be sufficient.

In (B), since the heating element 7 is not arranged surrounding the ink passage hole 8, the heat of the ink 3 inside the ink passage hole 8 is radiated and the ink 3 inside the ink passage hole 8 is quickly heated. It becomes possible to make it viscous, and there is no tailing.

In (C), (D), and (E), by providing the heating element 7 around the ink passage hole 8, the ink 3 quickly lowers the viscosity when the heating element 7 generates heat, and furthermore, when the heat generation stops, This is a heat generating section configuration in which the ink 3 quickly becomes highly viscous in the cooling section 14 on the downstream side. This has the advantage that there is no trailing or the like, and furthermore, the thermal response of the heat generating section is faster, so that the recording speed is faster.

As explained above, the dot formation region is formed by the heating element 7 and the cooling section 14 connected to the downstream side of the heating element 7. Further, in this embodiment, the area ratio of the heating element 7 to the cooling part 14 in the dot forming area is 1:1, but the area ratio is not limited to this.

Further, the magnitude of the voltage pulse applied to the heating element 7, the number of ink passage holes 8, and the pressure applied to the ink 3 are not limited to those of the above-mentioned embodiments, and may vary depending on the type of ink used and the ink. It goes without saying that it may be changed as appropriate depending on the size of the passage hole, etc.

In addition, although recording paper is used as the recording medium in the above-mentioned embodiments, it is also possible to use recording paper with relatively poor wettability, which is used for so-called whiteboards, electronic blackboard sheets, etc., and has a surface made of fluorine-based resin, etc. It can be used even if it is

<Effects of the Invention> In the recording head of the present invention described in detail above, by providing a temperature gradient in the recording dot formation area, the temperature of the ink after the dots are formed quickly decreases, and accordingly, the temperature of the ink quickly decreases. The viscosity is increased, and therefore it is possible to obtain a record without trailing.

[Brief explanation of the drawing]

Figure 1 is a schematic sectional view of the recording method, Figure 2 is an external view of the multi-type head, Part 3 is an explanatory diagram of the recording process, Figure 4 is an explanatory diagram of the configuration of the heat generating part of the recording head, and Figure 5 is FIG. 2 is an explanatory diagram of a conventional recording throat. 1 is a recording head, 2 is a housing, 3 is ink, 4 is a substrate, 5 is a reinforcing plate, 6 is an electrode, 7 is a heating element, 8 is an ink passage hole, 9 is a spacer, 10 is a recording paper, 11 is a platen roller , 12 is an ink dot, 14 is a cooling section, and 15 is a dot forming area. Applicant Canon Co., Ltd. Agent Patent Attorney Shukichi Nakagawa (Figure 1 Figure 4 To +s -+ Figure 5 (A) 3 (C) Figure CD)

Claims (2)

[Claims] (1) An insulating substrate having an ink passage hole, a housing provided on one surface of the insulating substrate for storing ink, and a housing provided on the other surface of the insulating substrate that selectively generates heat according to an image signal. a spacer provided on or near the heating element to maintain the heating element and the recording medium in a non-contact state, and a temperature gradient section for cooling the recorded dots within the dot forming area. A recording head characterized by: (2) The temperature gradient section is formed by a cooling section connected to the downstream side of the heating element in the recording progress direction, and the heating element and the cooling section constitute a dot forming area. The recording head according to item 1.