JP2001062981A - Method and device for plate-making and controlling method for plate-making thermal head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate the continuous defective perforation in the processing for a stencil base paper using a perforation means such as a thick film thermal head or the like to prevent the generation of defective printings such as strike- through, set-off and others and achieve the simplification of a manufacturing process and the lowering the manufacturing cost and material cost while preventing the generation of paper wastes and resin wastes caused by the continuous defective perforation. SOLUTION: In a control method and a control device thereof, the perforation timing of scanning lines of odd number order is shifted by Δt respectively from the perforation timing (d) of the constant period T representing [a]=ta1=ta2= ta3=ta4...=T controlled based on strobe signals of the general constant periods heretofore available and delayed to make longer timing pitches tb1, tb3... between the perforation timing of the even-numbered order and the perforation timing of the following odd-numbered order in the sub-scanning direction and set larger the width of a separation section 6 between perforations 5b and 5c dealing with the above timing pitches.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate making method and a plate making apparatus, and a method of controlling a plate making thermal head.

[0002]

2. Description of the Related Art Thermal heads used for image formation in various recording apparatuses include a thin-film type thermal head using a thin-film forming technique and a thick-film type thermal head not using this. When making a stencil sheet for stencil printing using such a thermal head, it is necessary to form a separated portion between adjacent perforations without fail and to form fine perforations in order to improve printing quality. Have been.
In addition, in order to enable stencil printing of A2 size or even larger size, it is required that the thermal head be made larger. Further, since the manufacturing process of the thermal head generally occupies a high ratio in the manufacturing process of the plate making apparatus, the simplification of the manufacturing process of the thermal head and the reduction of the manufacturing cost are required. ing.

In general, a thin-film thermal head is manufactured by an advanced process using an expensive semiconductor manufacturing apparatus such as a sputtering apparatus or a vacuum evaporation apparatus similar to the semiconductor manufacturing process. Although it is suitable for miniaturization, the manufacturing process is complicated and the manufacturing cost is expensive. In addition, if a special large-sized substrate-compatible manufacturing apparatus is not specially used, the size is at most about 8 to 12 inches. You can only make things. on the other hand,
Thick film thermal heads can be manufactured at low cost because they are manufactured by a simple manufacturing method, screen printing, and large-format thermal heads can be easily manufactured. It is practically extremely difficult to form accurately. As described above, the thin-film thermal head and the thick-film thermal head each have advantages and disadvantages.

In general, a thick-film type thermal head is formed by arranging a plurality of electrodes at predetermined intervals on an insulating substrate made of ceramic or the like, and forming a linear pattern of heating resistors on the upper surfaces of the electrodes. Its main part is configured.
When a drive voltage corresponding to the content of printing is applied to the electrodes, a predetermined potential difference is generated between adjacent electrodes, a current flows through the heating resistor therebetween, and heat corresponding to the energized energy is generated by the heating resistor. Emanated from the body. The heat propagates while diffusing toward the surface portion in contact with the recording medium, and thermal printing or ribbon transfer printing is performed on the recording medium. According to such a thick-film thermal head, an image (print dot) in which each dot is appropriately continuous can be formed by the heat distribution in a region wider than the heat generating region of each heat generating element formed between the electrodes. In addition, it is possible to obtain a print image of high quality print quality by a printing apparatus of a thermal recording paper printing system or a ribbon transfer printing system. Moreover,
As described above, there is also an advantage that the size of the entire thermal head can be increased and the cost can be reduced.

[0005]

However, when such a thick film type thermal head as described above is used for making a stencil sheet for stencil printing, the arrangement of electrodes in the main scanning direction (the width direction of the stencil sheet). Although the perforation size can be reduced by adjusting the interval, the width of the heating resistor is set to 100 μm in the sub-scanning direction (running direction of the stencil sheet).
Since it is extremely difficult to form a stencil sheet having a smaller dimension, it is extremely difficult to reduce the perforated dimension of the stencil sheet.
Moreover, since the heat generated from the heating resistor diffuses and propagates to the surface of the recording medium on which printing (heat application) is performed, the amount of heat finally applied to the recording medium per dot ( That is, the apparent heating area on the surface) is further increased. As a result, originally
There is a problem in that a plurality of perforations that must be formed with (separately) separated from each other are continuous, and a continuous perforation failure occurs. When printing is performed using a stencil sheet on which such continuous perforation failure has occurred, an excessive amount of ink penetrates from the portion of the continuous perforation failure, resulting in an excessive transfer amount of the ink to the printing paper. Printing problems such as strike-through, such as ink bleeding to the back side of printing paper, or set-off, where ink is re-transferred between printed materials because it is placed in a semi-dry state after printing. is there. In addition, in stencil printing, generally, the diameter of the dot actually printed by printing the ink on the printing paper is larger than the diameter of the perforation of the stencil. The ratio of the size of the actually printed dot diameter to the perforated diameter of the stencil is called a dot gain, and this dot gain usually has a value of about 200%.
Therefore, it is desirable to further reduce the perforation diameter of the stencil in consideration of the further enlargement of dots due to such dot gain. Becomes increasingly difficult.

In addition, in a portion where such continuous perforation failure occurs, a large number of small pieces of paper residue or resin residue which are completely separated from the surrounding stencil sheet and easily fall off are generated. In addition, there is a problem that print residue or resin residue accumulates in a smear state on the side surface or the upper surface of each part protruding from the substrate surface, such as a heating resistor or an electrode, or on the surface of the substrate itself, which greatly deteriorates the print quality of the thermal head.

[0007] In order to prevent the occurrence of continuous perforation failure of the stencil sheet which causes the above-described printing failure, the heating area of the heating resistor must be made smaller than before. In the head, as described above, the miniaturization of the size of the heating resistor in the width direction has already reached the limit, particularly in the sub-scanning direction, so that it has been extremely difficult to further miniaturize the heating area.

On the other hand, a thin-film thermal head is advantageous in terms of eliminating continuous perforation defects in stencil making of stencil paper and further miniaturizing perforation dimensions. This is because, in the manufacturing process of the thin-film thermal head, the width and the shape of the heating resistor can be significantly reduced in size as compared with the thick-film thermal head. However, on the other hand, as described above, the manufacturing process is complicated, the manufacturing cost is high, and it is difficult to cope with the large format. In particular, in regard to this large-format support, a large-sized thermal head is formed by connecting a plurality of thermal head blocks, so that a heat generation failure may occur at the joint, and the joint may be heated. There is a problem that white streak defects occur in printing in the above. In addition, due to individual differences in heat generation characteristics among the plurality of thermal head blocks, variations in print density between the thermal head blocks may adversely affect print image quality. Alternatively, precise alignment of multiple thermal head blocks requires extremely high alignment accuracy, but the probability of successful high-accuracy alignment is low, reducing the yield and There is also a problem that the cost is further increased.

As described above, the conventional thick-film type thermal head can cope with large-size printing which is practically extremely difficult with the thin-film type thermal head, and the manufacturing process is simple and the manufacturing cost can be reduced. Although it has a great advantage that it is possible, there has been a problem that continuous perforation failure occurs when making a stencil sheet, and it is extremely difficult to prevent this. In addition, with the occurrence of such continuous perforation defects, there is a problem that paper residues and resin residues tend to remain, which further causes perforation defects and printing defects.

In addition to the above-described method of making a stencil sheet using a thermal head as described above, a stencil sheet is formed by irradiating a laser beam on the stencil sheet with a laser beam to form a stencil sheet. A similar problem has arisen in ink-jet plate making, in which a solvent is projected onto a stencil sheet made of stencil using an ink-jet apparatus to make a plate. In other words, if you go further with high-resolution plate making,
Even if an attempt is made to perform fine independent perforation at a predetermined pitch in the main scanning direction or the sub-scanning direction, it is caused by technical difficulties in the plate making apparatus, its control method, and the plate making method, such as the precision of controlling the position and size of the perforation. Then, there is a problem that the perforation length in the main scanning direction or the sub-scanning direction becomes longer than the above-mentioned predetermined pitch, and continuous perforation failure occurs.

The present invention has been made in view of such a problem, and eliminates the occurrence of continuous perforation defects during stencil making on a stencil sheet, thereby preventing the occurrence of printing defects such as strike-through or set-off. A plate making method, a plate making apparatus and a plate making method capable of simplifying the manufacturing process and further reducing the manufacturing cost and material cost while preventing the generation of paper slag and resin slag generated due to continuous perforation failure. And a method of controlling the thermal head for printing.

[0012]

A stencil making method according to the present invention is a stencil making method for piercing a stencil sheet at a predetermined piercing pitch in a main scanning direction and a sub-scanning direction.
The perforations are provided every other or in a plurality in the one direction so as to provide a separation portion in which the stencil sheet remains between perforations adjacent in any one of the main scanning direction and the sub-scanning direction. It is characterized in that it is performed while being shifted from a predetermined perforation pitch. In addition, this plate making method, such as a plate making method using a laser beam, a plate making method using an inkjet, or a plate making method using a thermal head,
It is applicable to those using various means as the perforation means.

In the method of controlling a thermal head for stencil making according to the present invention, the heating elements arranged in the main scanning direction are selectively driven and the stencil sheet is relatively scanned in the sub-scanning direction.
In the method for controlling a stencil thermal head for performing perforation at a predetermined perforation pitch on the stencil sheet, the perforation is performed such that a separation portion where the stencil sheet remains remains between perforations adjacent in the sub-scanning direction. The present invention is characterized in that the perforation is performed at every other or every plural number in the sub-scanning direction while being shifted from the predetermined perforation pitch.

Here, the on-pulse timing of the heat generation control signal for controlling the heat generation timing of the heating element is shifted from a predetermined cycle corresponding to the predetermined perforation pitch, so that the perforation pitch in the sub-scanning direction is set to the predetermined pitch. May be offset from the perforation pitch.

[0015] The separation portion may be provided also between the perforations adjacent in the main scanning direction.

Further, the heating elements are formed at intervals of a plurality of electrodes arranged in the main scanning direction at predetermined intervals, and the width of the electrodes in the main scanning direction is equal to the width of the heating elements. A plate making thermal head formed to have a width larger than the width in the direction may be used.

The perforations shifted in one direction as described above may be in a state of being continuously perforated with the perforations adjacent to the perforations. This is because a separation portion that remains with a wide width can be reliably secured between the perforations adjacent to each other in the opposite direction.

Further, the method of shifting the perforation pitch may be such that, for example, regular shifting is performed for each even-numbered perforation in the sub-scanning direction. It goes without saying that irregular shifting, such as repeating shifting alternately, may be mixed. Alternatively, two perforations adjacent to one perforation can be shifted so as to approach one perforation at the center of the three perforations.
In this case, the continuous three perforations may be continuous perforations in some cases. However, the width between the three perforations and the perforations before and after the three perforations is wider than that when the three perforations are independently perforated. Can be reliably provided (remaining).

Further, the method of shifting the perforations according to the present invention is to shift the perforations so that the separated portion can be reliably left. That is, for example, even if the heat generation control signal (so-called strobe signal) is delayed due to some factor in the thermal print head control circuit and the perforation is shifted accidentally, or the perforation is displaced to the extent of an error, the deviation continues. Cannot be generated or a significant displacement cannot be generated, so that the separated portion cannot be reliably left. Therefore, it is needless to say that it is desirable as a technique of the present invention to positively provide the deviation of the perforation so as to surely provide the wide separated portion without being accidental.

A stencil making apparatus according to the present invention is a stencil making machine for piercing a stencil sheet at a predetermined piercing pitch in a main scanning direction and a sub-scanning direction. The method is characterized in that the perforations are shifted from the predetermined perforation pitch every other or in a plurality in the one direction so as to provide a separation portion where the stencil sheet remains between perforations adjacent in one direction. I have.

The stencil making apparatus according to the present invention comprises a thermal head control circuit for selectively driving the heating elements arranged in the main scanning direction, and the stencil sheet for perforating the stencil sheet at a predetermined perforation pitch. In a stencil making head having a stencil sheet sub-scanning means for scanning relatively in the sub-scanning direction with respect to the heating element, a separation section in which the stencil sheet remains between perforations adjacent in the sub-scanning direction is provided. The thermal head control circuit selectively drives the heating element while the stencil sheet sub-scanning means scans the stencil sheet, so that the perforations are formed in the sub-scanning direction at intervals of one or more. It is characterized by being shifted from the perforation pitch.

Here, the thermal head control circuit includes:
By shifting the on-pulse timing of the heat generation control signal for controlling the heat generation timing of the heating element from a predetermined cycle corresponding to the predetermined punching pitch, the pitch of the drilling in the sub-scanning direction is shifted from the predetermined punching pitch. It may be.

Further, the separation portion may be provided between the perforations adjacent in the main scanning direction.

The heating element is formed between a plurality of electrodes arranged in the main scanning direction at a predetermined interval, and the width of the electrode in the main scanning direction is set in the direction of the heating element in the main scanning direction. May be formed to have a width larger than the width of.

The stencil sheet sub-scanning means may be any means capable of scanning the stencil sheet in the sub-scanning direction relative to the heating element. Scanning may be performed in the scanning direction (so-called paper feed), or a stencil sheet may be fixed on a mounting table and the thermal print head body may be moved.

The external dimensions and positions of the perforations in the sub-scanning direction are determined depending on the scanning speed of the stencil sheet, the heat generation timing and the heat continuation time of the heat generating element, and the heat generation power. Since the print head differs depending on the print head, the scanning speed of the stencil sheet and the heat generation timing of the heat generating element may be set so as to ensure the separated portion by shifting the perforation in each case.

As a more specific method for shifting the perforation, the scanning speed of the stencil sheet is kept constant,
A method in which the heat generation start timing of the heating element is shifted from a fixed cycle and a method in which the heat generation start timing of the heat generation element is fixed and the speed is changed at the time of perforation in which the scanning speed of the stencil sheet is to be shifted are used.

Further, as a more specific method for providing a space between adjacent perforations in the main scanning direction,
In addition to the above-described method of increasing the width of the electrode in the main scanning direction to reduce the width of the heating element in that direction, the heating diffusion time is reduced by adjusting the heating duration time (heating duty). It is also possible to use a method of performing control so as to perform the control, or to use both methods in combination.

[0029]

According to the plate making method, the plate making apparatus and the method of controlling the thermal head for plate making according to the present invention, one stencil in the sub-scanning direction is provided so as to provide a separation portion where the stencil sheet remains between the perforations adjacent in the sub-scanning direction. Punching is performed at a predetermined pitch or every other number. In other words, even if the perforations shifted in one direction are continuous with the perforations adjacent in the shifted forward direction, the perforations adjacent in the opposite direction to the shifted forward direction are surely provided. A wide separation portion can be secured. As a result, it is possible to eliminate the occurrence of continuous perforation defects in the sub-scanning direction on the stencil sheet. As a result, it is possible to eliminate printing defects such as ink bleeding, strike-through or set-off, and a decrease in print quality due to an excessive amount of ink transfer to the printing paper.

Further, by shifting the on-pulse timing of the heat generation control signal for controlling the heat generation timing of the heat generation element from a predetermined cycle corresponding to a predetermined punching pitch,
The pitch of perforation in the sub-scanning direction is shifted from a predetermined perforation pitch. By controlling in this way, the thermal head body can be modified by modifying the thermal head control circuit or operating the thermal head control circuit using a general structure and a thick-film thermal head having a heating element. Since the present invention can be realized only by software modification, the present invention can be easily applied to drive control of a plate making apparatus using a thermal head including a thick film type thermal head body having a general structure. It becomes possible. As a result, the separation section can be reliably provided in the sub-scanning direction without increasing the cost of the entire apparatus and complicating the manufacturing process.

Further, by providing a sufficient space between the perforations adjacent in the main scanning direction, it is possible to prevent continuous perforation in the main scanning direction.

The heating elements are formed at intervals between a plurality of electrodes arranged in the main scanning direction at predetermined intervals, and the width of the electrodes in the main scanning direction is equal to the width of the heating elements in the same direction. By using a simpler method of using a larger plate-making thermal head, it is possible to reliably provide the above-described separation portion in the main scanning direction. As a result, the separation portion can be reliably provided in the main scanning direction without complicating the manufacturing process of the entire apparatus or increasing the cost.

[0033]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a diagram showing a schematic configuration of the plate making apparatus.
FIG. 2 is a plan view of a main part of a thermal head main body used in the apparatus, and FIG. 3 is a sectional view taken along line AA of FIG. This plate making machine
A thermal head body 100 in which the heating elements 1 are arranged in the main scanning direction, a thermal head control circuit 200 for selectively driving the heating elements 1, and a stencil sheet (not shown) in the sub scanning direction with respect to the heating elements 1. The main part thereof is constituted by a stencil sheet sub-scanning section (stencil sheet sub-scanning means) 300 to be scanned and a power supply circuit 400 for supplying a driving power supply voltage thereto.

The thermal head main body 100 is a so-called thick-film type thermal head. A thermal insulating layer 102 is formed on almost the entire surface of a substrate 101 made of ceramic, and a plurality of electrodes 103 are provided on the thermal insulating layer 102 at a predetermined interval. Are arranged in a comb-tooth shape, and the electrode 1 is further formed thereon.
A linear heating resistor 104 is formed so as to be orthogonal to 03, and a heating element 1 is formed between the electrodes 103. Then, a protective layer 105 is formed so as to cover almost the entire surface of the substrate 101 including the electrode 103 and the heating resistor 104 to protect them. The heat insulating layer 102 is a general one formed of a glass material and having a thickness of 40 to 100 μm. The electrode 103 has a thickness of 0.5 to 4 μm and is formed by solidifying a silver paste or a gold paste, or a general electrode formed of aluminum or the like. The heating resistor 104 is made of ruthenium oxide (RuO2).
The heating resistor 104 material obtained by mixing glass powder and a solvent is patterned by a screen printing method or the like, and is formed by curing and solidifying the material. The planar shape is a linear shape that is long in the same direction as the longitudinal direction of the thermal head main body 100. Therefore, the individual heating elements 1 formed using the heating resistors 104 are not substantially independent but are thermally continuous in the main scanning direction. Protective layer 10
Reference numeral 5 denotes a wear-resistant glass material having a thickness of 1 to 20 μm, and is formed so as to cover substantially the entire surface of the substrate 101 including the heating resistor 104 and the electrode 103.

As described above, the thermal head main body 100 has the same structure as the conventional laminated structure in terms of the laminated structure. However, the width (dimension) of the electrode 103 in the main scanning direction
Are formed to have a width larger than the interval between the electrodes 103, that is, the width (dimension) of each heating element 1 in the main scanning direction. In other words, within one pitch of the heating elements 1 in the main scanning direction, the larger the width of the electrode 103 is, the narrower the width of each heating element 1 is in the main scanning direction. By making the width of each heating element 1 in the main scanning direction sufficiently small as described above, even if the heat generated from the heating element 1 diffuses in the main scanning direction while propagating to the surface of the heating resistor 104, It is possible to eliminate continuous perforation between adjacent perforations in the main scanning direction and to reliably form (remain) the separated portion 7 in the main scanning direction. More specifically, the thermal head body 100 of the present embodiment is compatible with a dot density of 400 dpi, and the width of each heating element 1 in the main scanning direction is 23.5 μm.
m, the width of the electrode 103 in the same direction is 40 μm.

On the other hand, since the size of the heating element 1 in the sub-scanning direction depends on the width of the heating resistor 104, a stack formed by a general screen printing method such as the thermal head body 100 is used. Similar to a thick-film thermal head having a structure, the width of the heating resistor 104 can be reduced to a limit of 100 while maintaining practical accuracy.
It is up to about μm. For this reason, it is extremely difficult to modify the hardware of the thick-film type thermal head body 100 having a general structure to eliminate continuous perforation in the sub-scanning direction. Unless the perforation pitch in the sub-scanning direction is set to be at least larger than the width of the heating resistor 104, continuous perforation will occur in the sub-scanning direction. However, the dot density of perforation is further improved to achieve higher definition. In order to realize the above, it is desirable to reduce the perforation pitch in the sub-scanning direction. Therefore, the size of the heating element 1 in the sub-scanning direction is the same as that of a general thick film type thermal head, and as described later, the heating element 1 is formed by shifting the perforation intervals.
By the method on the control method and the method on the control circuit,
It is ensured that the wide separation portion 6 remains in the sub-scanning direction.

The stencil sheet sub-scanning section 300 scans the unperforated stencil sheet at a constant speed in the sub-scanning direction while synchronizing with the progress of the perforating operation based on the image data. Controlling system control circuit 301
An image processing / sub-scanning control circuit 302 including an image processing circuit for processing image data and a sub-scanning motor driving circuit for controlling the electromechanical rotation of the sub-scanning motor in synchronization therewith; A sub-scanning mechanism 3 for mechanically scanning (paper feeding) the stencil sheet in the sub-scanning direction at a constant speed using a driving force supplied by a scanning drive motor (not shown).
03.

The thermal head control circuit 200 includes a sub-scanning control circuit 201, a timing generation circuit 202, and a history control circuit 203. Each of the heating elements 1 based on various signals and data as shown in FIG. Is to control the heat generation operation. The timing generation circuit 202 stores image data (FIG. 6B) in a thermal head driving register (not shown) provided in the thermal head main body 100.
Signal (FIG. 6 (c)) and strobe for setting (so-called latching)
A signal and a clock signal (FIG. 6A) are output.
The history control circuit 203 supplies information on how to shift the perforation and image data to the sub-scanning control circuit 201 and the timing generation circuit 202, and also controls the heating elements 1 arranged in the main scanning direction based on the image data. A waveform for selectively driving is generated and is generated.
0 is supplied. The sub-scanning control circuit 201 is schematically shown in FIG. 6F based on the perforation shifting information and image data supplied from the history control circuit 203 and the clock signal supplied from the timing generation circuit 202. 6D, the punching timing of odd-numbered scanning lines in the sub-scanning direction is controlled by a conventional general strobe signal having a constant period as shown in FIG. 6D as a comparative example. ... = T, the drilling timing is shifted by Δt at intervals of Δt as shown in FIG. 6 (e). That is, the on-pulse timing of the strobe signal waveform is delayed by Δt.

As a result, the temporal pitch tb1, tb3,... Between the even-numbered punching timing and the subsequent odd-numbered punching timing in the sub-scanning direction becomes longer, so that the corresponding separation portion between the punches 5b, 5c becomes longer. 6 can have a large width. On the other hand, since the temporal pitches tb2 and tb4 between the odd-numbered drilling timing and the subsequent even-numbered drilling timing become shorter, the corresponding drilling 5a, tb4 becomes shorter.
The pitch between the holes 5b becomes narrow, and the two perforations 5a and 5b become severe. However, even if such continuous perforations 5a and 5b occur, the width of the separation portion 6 between the even-numbered perforations and the odd-numbered perforations described above can be reliably increased. By providing this large separation portion 6, it is possible to eliminate perforation defects such as continuous occurrence of continuous perforation.

Further, the control for shifting the odd-numbered holes is such that the conventional pulse waveform of the strobe signal having a constant period as shown in FIG. 6D is replaced with a waveform as shown in FIG. 6E. Since it can be realized by a simple method on the pulse timing, it is possible to reliably provide the separation portion 6 in the sub-scanning direction without complicating the manufacturing process of the device and increasing the cost. The continuous drilling defect that has occurred continuously can be eliminated by a simple and low-cost method.

Here, how much the punching timing in the sub-scanning direction should be shifted depends on the external dimensions of the heating element of the thermal head main body 100 in the sub-scanning direction, the amount of heat generation, and the amount of heat generated during propagation through the heating resistor 104. An appropriate shift amount is set based on the size of a heat area in which heat spreads and spreads in the sub-scanning direction (in other words, the feed speed of the stencil sheet). For example, when the resolution (dot density) in the sub-scanning direction is 400 dpi, assuming that the constant heat generation timing in the sub-scanning direction in the conventional control method is 2 ms / 1 cycle, the punching pitch in the sub-scanning direction Is 63.5 μm. It has been confirmed from various experiments by the present inventor that if a stencil sheet of a general material is used, it is experimentally desirable to provide the separation portion 6 having a width of 15% or more of one perforation pitch. Therefore, in order to secure such a separation part 6 having a width of 15% or more of one perforation pitch, that is, a width of about 9.5 μm or more in the sub-scanning direction, the amount of deviation Δt of the heat generation timing must be Δt =
It can be seen that 2 ms × 15% = 300 μs is sufficient.

Here, the stencil paper for thermal perforation includes:
There are two types: one obtained by laminating a heat-sensitive film such as a polyester film or a PET film on a Japanese paper or screen serving as a support, or one consisting of a single heat-sensitive film. Either of them can be used. .

FIG. 5 shows an example of a case where a stencil sheet is perforated using the plate making apparatus according to the present embodiment as described above. By shifting the timing of the odd-numbered punching in the sub-scanning direction in the direction of delay as described above,
For example, among the three perforations 5a, 5b, and 5c adjacent in the sub-scanning direction as shown in FIG. 5, the pitch in the sub-scanning direction is shorter between the perforations 5a and 5b, so that these two perforations are continuous. A perforation 5b and a perforation 5c, which are adjacent perforations on the opposite side, are surely provided with a separation portion 6 having a sufficient width. Moreover, since the width of the heating element 1 in the main scanning direction is narrow,
Also in the main scanning direction, the separation portion 7 is reliably secured between adjacent perforations (for example, between the perforations 5a and 5e).

On the other hand, on the other hand, as a comparative example, the same specifications as those used in the above-described embodiment are used on the basis of a conventional general strobe signal having a constant period as shown in FIG. As a result of an experiment in which the thermal head main body 100 was driven to pierce a stencil sheet having the same specifications as described above, as shown in FIG. In the test, continuous perforation failure occurred frequently in both the main scanning direction and the sub-scanning direction.

As described above, according to the method of controlling the thick film thermal head for plate making and the plate making apparatus controlled (driven) based on the method according to the present embodiment, the manufacturing process of the apparatus becomes complicated and cost increases. Since the separation portion 6 can be provided in the sub-scanning direction and the separation portion 7 can be provided in the main scanning direction without causing the problem, the occurrence of continuous drilling failure can be eliminated. It is possible to further improve the perforation quality of the stencil sheet while maintaining the advantages of the head, such as low cost and large format.

In the above-described embodiment, the thermal head main body 100 is fixed, and the stencil sheet, that is, the stencil sheet is mechanically scanned in the sub-scanning direction. (Not shown) or the like, and the thermal head body 100 may be moved (scanned) thereon.

In the above embodiment, the scanning speed (feed speed) of the stencil sheet is kept constant, and the thermal head control circuit 200 shifts the punching timing in the sub-scanning direction. It is needless to say that the method of the present invention is not limited to this. In addition, the perforation timing in the sub-scanning direction by the thermal head control circuit 200 is repeated at a fixed period timing in the same manner as in a general method of the related art.
The scanning speed of the stencil sheet according to 00 may be controlled so that the scanning speed at the time of performing the odd-numbered punching is lower than the scanning speed at the time of performing the even-numbered punching in synchronization with the punching timing.

In the above-described embodiment, a case has been described in which all odd-numbered holes are regularly shifted in the sub-scanning direction. In addition, for example, the holes may be shifted every multiple of three. Alternatively, a method of shifting every two perforations and every fifth perforation may be used.

Further, in the above-described embodiment, the separation portions 7 in the main scanning direction are surely left. However, the separation portions 7 in the main scanning direction are not limited to only leaving all the separation portions 7. It is needless to say that is not limited. This is because even if the separation portion 7 in the main scanning direction is damaged, according to the present invention, the separation portion 6 in the sub-scanning direction can be reliably left in a wide width. However, it is necessary to ensure that both the main and sub-direction separating portions 6 and 7 remain.
Needless to say, it is more desirable.

In the above embodiment, the electrode 103 is formed on the surface of the substrate 101, and the heating resistor 1
Although the case where the present invention is applied to a thick film type thermal head having a general laminated structure in which No. 04 is formed is shown,
The laminated structure of the thermal head main body 100 is not limited to this. In addition, the present invention is applied to a thick-film type thermal head having a structure in which a heating resistor 104 is buried in a groove by, for example, forming a groove in the substrate 101, and an electrode 103 is provided thereon. It is needless to say that it is also possible to apply.

Further, in the above-described embodiment, the case where a thermal head is used as the piercing means is shown.
The stencil making method according to the present invention controls the presence or absence of ink transfer by the presence or absence of perforation, so long as it is used for making a stencil sheet used in a so-called digital dot printing method, any perforation means can be used. Applicable. That is, in addition to the above, for example, a laser stencil method (method and apparatus) for irradiating a heat sensitive stencil paper with a laser beam and performing perforation by the thermal energy, or a solvent such as polyethylene, polypropylene or isobutylene for a support. An aliphatic hydrocarbon solvent, an aromatic hydrocarbon solvent, an alcohol solvent, or the like is projected onto a solvent-soluble stencil sheet obtained by laminating a soluble resin layer, and perforation is performed by melting a portion to which the solvent adheres. The present invention is also applicable to a plate making method and a plate making apparatus using a perforating means of an ink jet plate making method for performing the above.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of a plate making apparatus according to an embodiment.

FIG. 2 is a plan view of a main part of a thermal head main body.

FIG. 3 is a sectional view of the thermal head body taken along line AA.

FIG. 4 is a longitudinal sectional view of the thermal head main body taken along line BB, schematically showing a state of propagation of heat generated from the heating element and showing a laminated structure of the thermal head main body.

FIG. 5 is a diagram showing an example of a stencil sheet obtained by performing perforation using the stencil making machine according to the present embodiment.

FIG. 6 is a diagram showing an example of various signal waveforms used in the plate making apparatus according to the present embodiment.

FIG. 7 is a diagram showing an example of a stencil sheet obtained by performing perforation using a conventional stencil making machine as a comparative example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating element 5 Perforation 6 Separation part in sub scanning direction 7 Separation part in main scanning direction 100 Thermal head main body 200 Thermal head control circuit 300 Stencil base paper sub scanning part 400 Power supply circuit

Claims (10)

[Claims] 1. A stencil making method in which a stencil sheet is pierced at a predetermined piercing pitch in a main scanning direction and a sub-scanning direction, wherein the stencil sheets are adjacent to each other in one of the main scanning direction and the sub-scanning direction. A stencil making method, wherein the perforations are shifted from the predetermined perforation pitch in the one direction at intervals of one or more so as to provide a separation portion where the stencil sheet remains between the perforations. 2. A stencil making machine which selectively drives a plurality of heating elements arranged in a main scanning direction and relatively scans a stencil sheet in a sub-scanning direction to perforate the stencil sheet at a predetermined perforation pitch. In the method for controlling a thermal head, the predetermined number of the perforations may be provided in the sub-scanning direction at intervals of one or more so as to provide a separation portion where the stencil sheet remains between the perforations adjacent in the sub-scanning direction. A method for controlling a plate-making thermal head, wherein the method is performed while being shifted from a perforation pitch. 3. The method according to claim 1, wherein the on-pulse timing of the heat generation control signal for controlling the heat generation timing of the heat generating element is shifted from a predetermined cycle corresponding to the predetermined perforation pitch, so that the perforation pitch in the sub-scanning direction is set to the predetermined pitch. 3. The method according to claim 2, wherein the pitch is shifted from a perforation pitch. 4. The separating section as claimed in claim 2, wherein the separating section is provided between the perforations adjacent in the main scanning direction.
The method for controlling the thermal head for plate making described in the above. 5. The heating element is formed between a plurality of electrodes arranged in the main scanning direction at a predetermined interval, and the width of the electrode in the main scanning direction is equal to the width of the heating element. 5. The method according to claim 4, wherein a plate making thermal head larger than the width in the direction is used. 6. A stencil making apparatus for piercing a stencil sheet at a predetermined piercing pitch in a main scanning direction and a sub-scanning direction, wherein the stencil sheets are adjacent to each other in one of the main scanning direction and the sub-scanning direction. A stencil making apparatus characterized in that the perforations are shifted from the predetermined perforation pitch in the one direction at intervals of one or more so as to provide a separation portion where the stencil sheet remains between the perforations. 7. A thermal head control circuit for selectively driving the heating elements arranged in the main scanning direction, and the stencil sheet is pierced with respect to the heating elements in order to pierce the stencil sheet at a predetermined perforation pitch. A stencil sheet sub-scanning means for relatively scanning in the sub-scanning direction, wherein the stencil sheet sub-scanning is provided so as to provide a separation portion where the stencil sheet remains between perforations adjacent in the sub-scanning direction. While the means scans the stencil sheet, the thermal head control circuit selectively drives the heating element to shift the perforations from the predetermined perforation pitch every other or every plurality in the sub-scanning direction. A plate making device that is characterized. 8. The thermal head control circuit shifts an on-pulse timing of a heat generation control signal for controlling a heat generation timing of the heat generating element from a predetermined cycle corresponding to the predetermined perforation pitch, so that the sub-scanning direction is reduced. The plate making apparatus according to claim 7, wherein a pitch of the perforations is shifted from the predetermined perforation pitch. 9. The device according to claim 5, wherein the separation portion is provided between the perforations adjacent in the main scanning direction.
The plate making device described in the above. 10. The heating element is formed between a plurality of electrodes arranged in the main scanning direction at a predetermined interval, and the width of the electrode in the main scanning direction is equal to the width of the heating element. 10. The width in the direction is larger than the width in the direction.
The plate-making apparatus described in the above.