JP3681743B2 - Method and apparatus for recording data on heat-sensitive stencil sheet - Google Patents

Description

  The present invention relates to a method for recording data by heating and opening a heat-sensitive stencil sheet with a dot-like heat generating portion, and an apparatus therefor.

  2. Description of the Related Art Conventionally, as a data recording apparatus for a thermal plate making apparatus, a thermal head having a plurality of dot-like heat generating portions arranged at predetermined intervals in the main scanning direction and a platen roller facing the heat generating portion, for example, a polyester resin The platen roller is a heat-sensitive stencil sheet (hereinafter referred to as “base paper”) made of only a biaxially stretched thermoplastic resin film made of or a laminate of a porous support such as a nonwoven fabric or Japanese paper on the film. It is known that data is recorded by heating the film and opening the film by selectively heating the heating part while moving the base paper in the sub-scanning direction perpendicular to the main scanning direction. Yes.

  When recording data by opening holes in the above base paper, if the holes formed in the base paper are large, the dot diameter of the ink that adheres to the printing paper through these holes will increase, and these dots will be connected to reduce the image quality. Will be invited. Therefore, it is desirable that the holes formed in the base paper have an optimum diameter and are individually independent.

  By the way, generally in the manufacturing process of a thermoplastic resin film, heat processing is added at the end of the extending process. This heat treatment is performed in order to remove the heat shrinkage force that causes distortion after being stretched from the film, but for the film used for the base paper, adjusting the heat treatment time, the amount of heating, etc. Many films have some heat shrinkage force remaining (see Patent Document 1). This is because the internal stress remains so that the portion melted by the heat generated by the heat generating portion is quickly opened. On the other hand, if the remaining heat shrinkage force is too strong, the holes formed in the film are enlarged and connected to adjacent holes, resulting in the above disadvantages.

Japanese Examined Patent Publication No. 6-45267

In order to deal with the above problems, conventionally, the heat shrinkage rate of the film is set finely to suppress the expansion of the holes, and the size of the heat generating part of the thermal head is made finer so that the holes can be opened. In order to prevent the holes from continuing, it has been devised to reduce the size.
However, the setting of the heat shrinkage rate for suppressing the expansion of the hole sacrifices the perforation sensitivity of the film, that is, the ease of opening, and there is a problem that it leads to a decrease in the opening rate. Further, if the heat generating part is made finer, the thermal efficiency of the thermal head is lowered, resulting in a decrease in the aperture ratio, and the heat head is shortened due to the heat concentrated on the heat generating part. is there.

  Therefore, the present invention has been made to solve the above-described problems, and the opening is completely independent on the heat-sensitive stencil sheet with a simple configuration without causing a decrease in the perforation sensitivity of the film or shortening the life of the thermal head. It is an object of the present invention to provide a data recording method and apparatus for a heat-sensitive stencil sheet that can form stencil.

  According to the observation by the present inventors, as shown in FIG. 7, it has been found that the continuous opening formed in the film mainly occurs in the sub-scanning direction, that is, the moving direction of the base paper. The reason for this is clarified in Japanese Patent Application No. 5-116962 by the applicant of the present application, but after the energization to the heat generating part of the thermal head is stopped, the heat generating part has a temperature equal to or higher than the film melting point for a while. Therefore, an opening that is longer than the length of the heat generating portion is formed in the sub-scanning direction in relation to the movement of the base paper, and this occurs due to the next opening area. Therefore, in order to prevent the continuation of holes in the sub-scanning direction and form completely independent openings, it is important to suppress the hole expansion in the sub-scanning direction.

  For this reason, as a result of intensive research on how to suppress the hole expansion in the sub-scanning direction, the present inventors have tried to obtain an opening of an appropriate size by heating once by the heating portion. Since the holes in the sub-scanning direction are expanded and the holes are continuous, if the opening to the film and the enlargement / shaping of the openings are performed step by step using the two heat generating parts, It has been found that independent and optimally sized apertures can be obtained.

The present invention has been made based on the above knowledge, and the data recording method on the heat-sensitive stencil sheet according to the present invention performs sub-scanning while making contact with a plurality of dot-like heating portions arranged in two rows along the main scanning direction. A second row in which the heat sensitive stencil sheet is moved in a direction, the base paper is perforated by a first row heat generating portion that generates heat at a temperature higher than the film melting temperature of the base paper, and heat is generated at a temperature lower than the film melting temperature of the base paper. The opening is reheated and shaped by the heat generating part.

In the data recording method on the heat-sensitive stencil sheet of the present invention, the first row of heat generating portions may be larger than the second row of heat generating portions, and the first and second rows adjacent in the sub-scanning direction. These two heat generating sections may be driven simultaneously by the same driver.

Further , the data recording apparatus for the heat-sensitive stencil sheet of the present invention has a plurality of dot-like heat generating portions arranged along the main scanning direction, and moves the heat-sensitive stencil paper in the sub-scanning direction while contacting the heat generating portions. In a data recording apparatus for a heat-sensitive stencil sheet that selectively heats a heat generating portion to open a heat-sensitive stencil sheet,
The heat generating portions are arranged in two rows, and heat is generated at a temperature lower than the film melting temperature of the base paper, and the first row of heat generating portions that open the base paper by generating heat at a temperature higher than the film melting temperature of the base paper. And the second row of heat generating parts to reheat and shape the apertures,
The relationship between S ₂ = nP is satisfied , where P is the heating repetition pitch of the base paper, S ₂ is the center-to-center pitch between the heat generating portions in the first row and the second row , and n is the integer. To do.

In the data recording apparatus for the heat-sensitive stencil sheet of the present invention, the first row of heat generating portions may be larger than the second row of heat generating portions, and the first and second rows adjacent in the sub-scanning direction. These two heat generating sections may be driven simultaneously by the same driver.

According to the present invention, a plurality of dot-like heat generating portions are arranged in two rows in the main scanning direction, but the heat generation temperature is a film in which the heat generating portions in the first row on the upstream side in the sub-scanning direction can open the base paper. The temperature is set to be higher than the melting temperature, and is set to a temperature range in which the second row of heat generating portions is lower than the film melting temperature of the base paper and does not open the base paper. The center-to-center pitch S2 between the first row of heat generating portions and the second row of heat generating portions is set equal to the heating repetition pitch P of the base paper when n is 1, and satisfies the relationship S2 = P. Yes. The base paper that has moved in the sub-scanning direction is opened in contact with the first row of heat generating portions, but the size of the opening may be an optimal size that is not continuous with adjacent openings. , It may be formed smaller than that.

Subsequently, the apertures are reheated in contact with the heat generating portions in the second row as the base paper moves. Here, when the opening is formed to be smaller than the optimum size, the opening is radiated by internal stress remaining around the opening in order to soften by reheating until the opening edge does not melt. It is shaped by spreading in the direction. As the opening expands and the heating effect of the second row of heat generating parts with respect to the opening edge decreases, the temperature of the opening edge decreases and hardens again, maintaining the balance with the surrounding internal stress and opening the hole. Expansion stops. As a result, the aperture is shaped to an optimum size that does not continue to other apertures in the sub-scanning direction, and the aperture ratio increases.
Note that the length and the amount of heat generated by the individual heat generating portions in the second row are set within a range in which the holes already formed in the optimal size in the heat generating portions in the first row are not further expanded. Is preferred.

As described above, according to the present invention, after the holes are opened in the first row of heat generating portions, the holes are reheated in the second row of heat generating portions to expand and reshape the openings. Can be formed.
In addition, since the hole area ratio can be increased by the second row of heat generating portions, there is no problem even if the hole area ratio of the first row of heat generating portions is low. Therefore, each dot-like heat generating portion in the first row can be miniaturized to a size sufficient to make the opening and opening independent, and an opening having an optimum size can be obtained by heating twice. Thus, the current applied to the heat generating portion can be kept as low as possible, and the durability life can be extended.
Furthermore, by simultaneously driving the two heat generating portions in the first row and the second row adjacent in the sub-scanning direction with the same driver, the configuration can be simplified and compared with the case where the two heat generating portions are driven independently. It can be made cheap.

First, a first embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a partially enlarged plan view of a thermal head which is a recording apparatus for recording data by melting and opening a heat-sensitive stencil sheet in a heat-sensitive plate making apparatus. In the thermal head 1, the main heater HM which is a dot-like main heat generating portion is arranged with a predetermined pitch P along the main scanning direction. The sub-heater HS1, which is a dot-like sub-heat generating portion, is arranged upstream of the main heater HM in the sub-scanning direction orthogonal to the main scanning direction, and has the same pitch as the main heater HM along the main scanning direction. Each is arranged with P.

The sub heater HS1 has the same width W in the main scanning direction as the main heater HM, and the length LS1 in the sub scanning direction is shorter than the length LM of the main heater HM. The center-to-center pitch S1 of the main heater HM and the sub-heater HS1 is S1 when the heating repetition pitch of the base paper by the heaters HM and HS1 is P, which is the same as the main scanning direction pitch of the main heater HM, and the integer is n. = P (n + 0.5) is satisfied, and FIG. 1 shows the case where n is 1, that is, the case of S1 = 1.5P.
Here, as specific examples of the above dimensions, the main scanning direction pitch P of the main heater HM and the sub heater HS1 is 63.5 .mu.m, the center pitch S1 between the main heater HM and the sub heater HS1 is 95.25 .mu.m, the main heater HM and the sub heater. It is appropriate to set the width W of HS1 in the main scanning direction to 30 .mu.m, the length LM in the subscanning direction of the main heater HM to 40 .mu.m, and the length LS1 in the subscanning direction of the subheater HS1 to 10 .mu.m.

  FIG. 2 is an enlarged sectional view of the thermal head 1 in the sub-scanning direction. On the non-conductive substrate 2, a heating resistor layer 3 of a predetermined length made of a thin film metal, an electrode layer 4 made of aluminum, and a protective film layer 5 are sequentially laminated, and a part of the electrode layer 4 is removed by etching to form the main heater HM and the sub-heater HS1, and the electrode 41 of the electrodes 41, 42, 43 constituting the electrode layer 4 is a power source. The electrode 43 is connected to a driver (not shown). With this configuration, the two heat generating portions of the main heater HM and the sub heater HS1 adjacent in the sub-scanning direction are driven simultaneously by the same driver. A platen roller 6 is arranged so as to be in contact with the thermal head 1 so as to be rotatable in the direction of arrow a, and a base paper 7 is passed through the outer peripheral surface of the platen roller 6 along the sub-scanning direction. The base paper 7 includes a thermoplastic resin film 71 located on the thermal head 1 side and a porous fiber sheet 72 located on the platen roller 6 side. The film 71 and the fiber sheet 72 are integrally formed with an adhesive or the like. It is stuck.

The plate making operation of the thermal plate making apparatus having the thermal head 1 having the above configuration will be described.
The main heater HM and the sub-heater HS1 are selectively heated when current is applied to the base paper 7 in accordance with image data to be subjected to plate making. However, as shown in the graph of FIG. The heating temperature T2 of the sub-heater HS1 is set to be equal to or lower than the melting temperature T0, which is a temperature range in which the base paper 7 is not perforated.

  The base paper 7 moves in the sub-scanning direction in accordance with the rotation of the platen roller 6 while being in contact with the thermal head 1, and as shown in FIG. It is melt-opened. At this time, as shown in FIG. 3A, the sub-heater HS1 that generates heat to the temperature T2 substantially simultaneously with the main heater HM has a center-to-center distance S1 = 1. A heat treatment portion 74 that does not reach the opening is formed by contacting a position on the base paper that is separated by 5P. As shown in FIG. 3C, the heat treatment portion 74 is located at a boundary portion between the apertured portions 75 and 77 adjacent to each other in the sub-scanning direction which is subsequently opened by the main heater HM. Further, the heat treatment portion 74 serves as a hole expansion stopper in the sub-scanning direction because the film is highly crystallized by the heat treatment, the thermal contraction force is reduced, and the perforation sensitivity is lowered.

Subsequently, when the base paper 7 moves by the heating repetition pitch P in the sub-scanning direction, the main heater HM and the sub heater HS1 generate heat again. At this time, as shown in FIG. 3B, the opening portion 75 adjacent to the heat treatment portion 74 is melted and opened by the main heater HM, but the heat treatment portion 74 upstream of the opening portion 75 in the sub-scanning direction. Expansion to the side is prevented. Simultaneously with the opening of the hole 75, the heat treatment portion 76 is formed by the sub heater HS1.
Thereafter, similarly, when the base paper 7 moves by the heating repetition pitch P, the apertured hole portion 77 and the heat treatment portion 78 shown in FIG. 3C are formed. The hole opening 77 is prevented from expanding downstream in the sub-scanning direction by the heat treatment section 74 and does not continue to the hole opening 75.
In this way, the presence of the heat treatment portion can prevent continuity between the apertured portions adjacent to each other in the sub-scanning direction. Therefore, when the apertured portions are formed in a matrix on the base paper as shown in FIG. In addition, it is possible to obtain completely independent openings.

Next, the second embodiment will be described with reference to FIG. 5, but the description thereof will be omitted because it is the same as the first embodiment except for matters to be noted.
Similarly, in the thermal head 20 of this embodiment, a plurality of dot-like heat generating portions are arranged in two rows in the main scanning direction. However, contrary to the above example, the heat generation in the first row upstream in the sub-scanning direction is performed. The heater is the main heater HM and the second row of heat generating portions downstream thereof is the sub-heater HS2, and the center-to-center pitch S2 of these heater rows is set equal to the heating repetition pitch P of the base paper. Further, as shown in the graph of FIG. 5, the heat generation temperature T1 of the main heater HM is set to be equal to or higher than the melting temperature T0 of the base paper film 71, and the heat generation temperature T2 of the sub heater HS2 is set to be equal to or lower than the melting temperature T0.

In the thermal head 20, when the holed portion of the base paper 7 comes to the contact position with the main heater HM, the hole is melted and opened. It is preferable that the size of the hole is an optimal size that does not continue with the adjacent hole in the sub-scanning direction. However, the temperature drop of the main heater HM and the fibers on the back surface of the hole to be opened There may be a case where a sufficiently large opening cannot be obtained due to heat being taken away due to being dense or lump. In this case, the opening edge is reheated by the sub-heater HS2 and is softened even if it is not melted. Therefore, the opening is enlarged and shaped to an optimum size based on the internal stress remaining around the opening, Thereby, a hole area ratio can be improved.
It should be noted that the opening already formed in the optimum size in the main heater HM is not further expanded by the sub heater HS2.

A thermal head 30 according to the third embodiment is a combination of the thermal heads 1 and 20. That is, as shown in FIG. 6, this thermal head 30 has a plurality of dot-like heat generating portions arranged in three rows in the main scanning direction, and the first sub-heater HS1, main heater HM, The second sub-heater HS2 is used. Further, the pitch between the centers of the heater rows is set to S1 (= 1.5P) and S2 (= P), respectively, as in the above embodiment.
In the thermal head 30 having the above-described configuration, the first sub-heater HS1 forms a heat treatment portion at the boundary between the openings, the main heater HM opens the opening, and the second sub-heater HS2 Enlarge and shape the aperture.

  As is clear from the above description, according to the data recording method and apparatus for the heat-sensitive stencil sheet of the first embodiment, on the boundary portion between the apertured portions adjacent to each other on the base paper in the sub-scanning direction, Since the heat treatment part that functions as a hole expansion stopper is formed by the first row heat generating part (sub heater), the opening formed by the second line heat generating part (main heater) expands in the sub-scanning direction. And can form completely independent apertures. Further, by simultaneously driving the two heat generating portions in the first row and the second row adjacent in the sub-scanning direction with the same driver, the configuration can be simplified and compared with the case where the two heat generating portions are driven independently. It can be made cheap.

  According to the data recording method and apparatus of the second embodiment, the first row of heat generating portions (main heaters) are used to open holes, and then the second row of heat generating portions (sub heaters) are reheated to expand the openings. Since shaping is performed, it is possible to form an opening having an optimum size independent of each other. In addition, since the hole area ratio can be increased by the second row of heat generating portions, there is no problem even if the hole area ratio of the first row of heat generating portions is low. Therefore, each dot-like heating part in the first row can be miniaturized to a size sufficient to make the opening and the opening independent, and an opening having an optimum size can be obtained by heating twice. Therefore, the current applied to the heat generating portion can be kept as low as possible, and the durability life can be extended. Furthermore, by simultaneously driving the two heat generating portions in the first row and the second row adjacent in the sub-scanning direction with the same driver, the configuration can be simplified and compared with the case where the two heat generating portions are driven independently. It can be made cheap.

  According to the data recording apparatus of the third embodiment, the first embodiment and the second embodiment are combined, and the first row of heat generating parts (first sub-heaters) are arranged between the openings. Heat treatment is performed, the holes are opened in the second row of heat generating parts (main heater), and the holes are enlarged and shaped in the third row of heat generating parts (second sub heater). A hole having a size can be formed more reliably.

It is an enlarged plan view and temperature distribution diagram of a thermal head. It is an expanded sectional view of the thermal head of FIG. 1 and a base paper. It is a figure explaining the process of the opening and heat processing by the thermal head of FIG. It is the elements on larger scale of the base paper opened by the thermal head of FIG. It is an enlarged plan view and temperature distribution diagram of another thermal head. FIG. 6 is an enlarged plan view and a temperature distribution diagram of a thermal head in which the thermal heads of FIGS. 1 and 5 are combined. It is a top view which shows the continuous state of the opening in the base paper perforated with the conventional thermal head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Thermal head, 6 ... Platen roller, 7 ... Base paper, 73, 75, 77 ... Opening hole part, 74, 76, 78 ... Heat processing part, HM ... Main heater, HS1, HS2 ... Sub heater.

Claims (6)

The first row of heat generated by moving the heat-sensitive stencil sheet in the sub-scanning direction while making contact with a plurality of dot-like heating portions arranged in two rows along the main scanning direction, and generating heat at a temperature higher than the film melting temperature of the base paper. A method of recording data on a heat-sensitive stencil sheet, wherein the base paper is perforated by a section, and the openings are reheated and shaped by a second row of heat generating sections that generate heat at a temperature lower than the film melting temperature of the base paper. 2. The method of recording data on a heat-sensitive stencil sheet according to claim 1, wherein the first row of heat generating portions is larger than the second row of heat generating portions. 3. The method of recording data on a heat-sensitive stencil sheet according to claim 1, wherein the two heat generating portions in the first row and the second row adjacent in the sub-scanning direction are simultaneously driven by the same driver. A plurality of dot-like heat generating parts are arranged along the main scanning direction, the heat-sensitive stencil sheet is moved in the sub-scanning direction while being in contact with these heat-generating parts, and the heat generating part is selectively heated to open the heat-sensitive stencil sheet. In a data recording device for heat-sensitive stencil paper,
The heat generating portions are arranged in two rows, and heat is generated at a temperature lower than the film melting temperature of the base paper, and the first row of heat generating portions that open the base paper by generating heat at a temperature higher than the film melting temperature of the base paper. And the second row of heat generating parts to reheat and shape the apertures,
The heating repetition pitch of the base paper is P, and the center-to-center pitch between the first row of heating portions and the second row of heating portions is S. ₂ , Where n is an integer, S ₂ A data recording device for heat-sensitive stencil paper satisfying the relation of nP. 5. The apparatus for recording data on a heat-sensitive stencil sheet according to claim 4, wherein the heat generating portion in the first row is larger than the heat generating portion in the second row. 6. The data recording apparatus for heat-sensitive stencil paper according to claim 4, wherein two heat generating portions in the first row and the second row adjacent in the sub-scanning direction are simultaneously driven by the same driver.

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