JPH07156429A - Current supply transfer recording apparatus and head - Google Patents

Abstract

PURPOSE:To make the close contact of an ink ribbon and a recording head excellent, to prevent the generation of long-term discharge and to perform recording free from density irregularity. CONSTITUTION:A current supply recording head 4 is arranged to the lower part of a platen 2 feeding image receiving paper 3 and a recording electrode IC 5 is attached to the head 4 and a recording electrode 6 is loaded with a common electrode 7 having a surface inclined with respect to the recording electrode 6. An ink ribbon 11 is held between the platen 2 and the current supply recording head 4 and the resistance layer of the ink ribbon 11 is being in contact with the contact part provided to the inclined surface of the common electrode 7. Since an insulating film 31 is formed outside from the contact part of the common electrode 7, the continuity surface with the ink ribbon 11 is not changed and the generation of discharge can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies an electric current to the resistance layer of an ink ribbon composed of an ink layer coated with ink and a resistance layer which generates heat when energized, and heats the resistance layer to form an image-receiving paper superposed on the ink layer. The present invention relates to an electric transfer recording apparatus and an electric transfer recording head that transfer ink.

[0002]

2. Description of the Related Art In recent years, thermal transfer recording has been adopted as a recording system for printers, facsimiles and the like because of its features of low cost, small size, light weight and easy maintenance. However, in the method using the thermal head, the thermal efficiency for heating the ink on the ink ribbon is low, and it is difficult to increase the printing speed due to the heat stored in the thermal head itself.

Therefore, an electric transfer recording system has been put into practical use in which heat is generated in the ink ribbon according to a recording signal, and the heat is used to heat the ink to transfer it to the image receiving paper.
The recording principle of this electric transfer recording system will be described with reference to FIG.

The ink ribbon 140 is composed of a resistance layer 141 and an ink layer 142 coated with ink to be transferred to the transfer paper 150 by heat. The recording head 143 is composed of a recording electrode 144 and a supporting member 145. The recording electrode 144 is connected to an external recording electrode drive circuit 146 that drives the recording electrode 144 according to a recording signal.

The ink ribbon 140 is superposed on the transfer paper 150, sandwiched between the recording electrode 144, the platen 149, the common electrode shaft 147 and the auxiliary roller 148, and is conveyed by the platen 149.

Recording electrode 144 and common electrode shaft 147
When the recording electrode drive circuit 146 applies a voltage to the recording electrode 144 according to image information,
The recording current flows in the direction of arrow L.

Since the contact area between the recording electrode 144 and the resistance layer 141 is smaller than the contact area of the common electrode shaft 147, the current density inside the resistance layer 141 near the recording electrode 144 becomes high, and the Joule heat generated causes heat generation. The ink of the ink layer 142 that is in contact with the resistance layer 141
And the image is formed.

In the energization transfer recording system as described above, the resistance layer 141, which is a heat source, moves along with the recording operation, so that there is no heat storage and no cooling time is required, and the heat source is close to the ink layer 142. Therefore, there is an advantage that high-speed printing is possible because the heat transfer efficiency is good.

Further, in recent years, a line type recording head having a plurality of recording electrodes has been adopted in order to perform printing in a wide range from postcard size to A4 size at high speed. However, the recording current is the resistance layer 22 of the ink ribbon 11.
Since the electric field is transmitted from the common electrode to the recording electrode while slightly expanding in the inside, in the electric transfer recording apparatus using such a line type recording head, when a plurality of adjacent recording electrodes are driven, the adjacent recording is performed. Since the recording current flowing into the electrodes spreads out, interference occurs, and the recording current is not evenly transmitted to each recording electrode, resulting in density unevenness.

In order to solve this drawback, there is one in which the distance between the recording electrode and the common electrode is shortened. As a recording head having a short inter-electrode distance, a counter electrode 156 including a pair of recording electrodes 151 and a common electrode 152 as shown in FIG.
A recording head (see Japanese Patent Laid-Open No. 63-179768), which contacts the ink ribbon 154 on a plane, and a recording electrode 160 and a common electrode 161 facing each other, as shown in FIG. 19, are embedded in an insulating support 162. Ink ribbon 16 with structure
4 and a recording head that is in vertical contact with the recording head (Japanese Patent Laid-Open No. 3-11475)
No. 1).

[0011]

However, in the recording head shown in FIG. 18, the end portion M of the contact surface of the common electrode 152 which contacts the resistance layer 153 of the ink ribbon 154.
However, the conductive width of the ink ribbon 154 may be widened due to a traveling problem such as slack.

As a result, the state of continuity or non-conduction occurs continuously, which causes discharge, which causes problems such as abrasion of the electrodes 151 and 152 and cutting of the ink ribbon 143.

Further, in the recording head shown in FIG.
Since the recording electrode 160 and the common electrode 161 were covered with the insulating support 162, the conduction width between the resistance layer 163 and the electrode did not change and no discharge occurred.

However, since the wear rate and the thermal expansion coefficient of the electrodes 160 and 161 and the insulating support 162 are different, the thermal expansion coefficient and the like due to the heat of the electrodes 160 and 161 and the insulating support 162 when continuing recording. The balance was broken, and the electrodes and the insulating support 162 were burdened with each other. Therefore, the electrodes were damaged and stable recording could not be performed.

Further, when the electrodes are in contact with each other over the entire plane, the pressure applied to the electrodes is low, so that there is a problem that an image with a low density is obtained. The present invention solves the above-mentioned drawbacks of the prior art, has excellent adhesiveness between the ink ribbon and the recording head, does not cause discharge for a long time, and can perform recording without density unevenness, and an electric transfer recording head. The purpose is to provide.

[0016]

In order to solve the above-mentioned problems, the first invention is to transfer an ink layer having a color material to be transferred onto a thermal transfer paper and to generate heat when energized to transfer the color material of the ink layer. An ink ribbon composed of a resistance layer for transferring to paper, a carrying stage for carrying the ink ribbon together with the transfer paper, a recording electrode in contact with the resistance layer of the ink ribbon, and a contact between the recording electrode and the ink ribbon. A common electrode that is in contact with the resistance layer of the ink ribbon at a position different from the position and is electrically connected to the recording electrode with a predetermined width in the ink ribbon transport direction, and the common electrode outside the contact portion in the ink ribbon transport direction. And an insulating means provided on the surface of the common electrode to insulate the surface of the common electrode so that the common electrode and the ink ribbon do not come into contact with each other by a predetermined width or more.

In order to solve the above-mentioned problems, a second aspect of the present invention is for transferring an ink layer having a coloring material transferred to a transfer paper and generating heat when energized to transfer the coloring material of the ink layer to the transfer paper. An ink ribbon composed of a resistance layer, a transport means for transporting the ink ribbon together with a transfer paper, a recording electrode in contact with the resistance layer of the ink ribbon, and a position different from a position where the recording electrode and the ink ribbon are in contact with each other. Is formed in a shape such that the resistance layer of the ink ribbon comes into contact with the ink ribbon with a predetermined width in the conveyance direction at a position of, and the ink ribbon does not contact the common electrode outside the contact portion in the conveyance direction of the ink ribbon. And a common electrode.

In order to solve the above-mentioned problems, the third invention is such that the common electrode is formed in a convex shape, and the common electrode is provided on the recording electrode so that the convex protrusion is located on the resistance layer of the ink ribbon. The present invention relates to the second invention.

In order to solve the above-mentioned problems, the fourth invention is a third invention comprising an insulating means for insulating the outer surface of the contact portion where the protruding portion of the common electrode comes into contact with the resistance layer of the ink ribbon. Relates to the invention.

In order to solve the above-mentioned problems, a fifth aspect of the present invention is for transferring an ink layer having a color material to be transferred onto a transfer paper and generating heat when energized to transfer the color material of the ink layer onto the transfer paper. In an energization transfer recording head for energizing an ink ribbon composed of a resistance layer, a recording electrode in contact with the resistance layer of the ink ribbon, and a surface provided on the recording electrode and inclined with respect to the recording electrode are provided. A common electrode that contacts the resistance layer of the ink ribbon on the inclined surface with a predetermined width in the transport direction of the ink ribbon, and a contact portion provided on the surface of the common electrode and the common electrode and the ink ribbon in the transport direction of the ink ribbon. And an insulating means for insulating the surface of the common electrode so as not to come into contact with the outside of the common electrode.

In order to solve the above problems, in the sixth invention, the common electrode is provided on the recording electrode so that the tip portion of the recording electrode is located in front of the extension line of the inclined surface of the common electrode. It relates to the fifth invention.

In order to solve the above-mentioned problems, a seventh aspect of the present invention is for transferring an ink layer having a color material to be transferred onto a transfer paper and generating heat when energized to transfer the color material of the ink layer onto the transfer paper. In an energization transfer recording head that energizes the ink ribbon as the ink ribbon including the resistance layer is conveyed by the platen roller, the ink ribbon is in contact with the resistance layer of the ink ribbon and the ink ribbon with the platen roller. And a curved surface having a curvature smaller than that of the platen roller provided on the recording electrode, and contacting the resistance layer of the ink ribbon with a predetermined width in the transport direction of the ink ribbon on the curved surface. A common electrode that holds the ink ribbon between the platen roller and the common electrode that is provided on the surface of the common electrode and the ink. In which carbon and is provided with an insulating means for insulating the surface of the common electrode so as not to contact with the outer contact portion in the conveying direction of the ink ribbon.

[0023]

According to the present invention, in the above structure, the end portion of the contact surface of the common electrode that contacts the resistance layer of the ink ribbon is electrically insulated so that the area of the conductive portion of the common electrode does not change, and the discharge is performed. Wear of the electrode part due to the occurrence of
This makes it possible to eliminate the inferiority of printing.

[0024]

【Example】

(First Embodiment) A first embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the configuration of an electric transfer printer 1 which is an embodiment of the present invention. The platen 2 is arranged at the substantially central portion of the main body. The platen 2 wraps the image-receiving paper 3 to prevent the misregistration so that the misregistration does not occur when the colors are superimposed and transferred as in color printing.

An energization recording head 4 is provided below the platen 2.
Is provided. The energizing recording head 4 controls the recording electrode I
C5 is attached, and a common electrode 7 is mounted on the recording electrode 6 and fixed by a screw 8. The energization recording head 4 has a structure in which it is separated from the platen 2 in the direction of arrow A by a solenoid 9 and is urged in the direction of arrow B by a compression spring 10 to pressurize the platen 2.

The ink ribbon 11 is interposed as a transfer medium between the platen 2 and the electric recording head 4. The ink ribbon 11 is conveyed from the ink ribbon supply roll 13 by a pair of drive rollers 12.

The drive roller pair 12 is connected to a drive shaft of a pulse motor (not shown), and is rotationally driven if necessary.
The current-carrying recording head 4 is attached to the fixed base 15 with the screw 14 so that the recording electrode 6 and the common electrode 7 both come into contact with the ink ribbon 11 at predetermined positions.

The fixed base 15 is attached to a shaft 17 of a support portion 16 attached to the printer body 1. The fixed base 15 is rotatable in both directions of arrows A and B around the central axis of the shaft 17, and is positioned by the shaft 17 except in the rotational direction.

On the left side of the platen 2, there is provided a paper feed cassette 18 containing the image receiving paper 3. The paper feed cassette 18 is detachable from the side surface of the printer body 1.

The image receiving paper 3 is taken out from the paper feed cassette 18 and conveyed toward the platen 2. The image receiving paper 3 is wound around the platen 2, and the tip of the image receiving paper 3 is fixed and held on the platen 2 by the grip 19. After the leading edge of the image receiving paper 3 passes through the recording area by the counterclockwise rotation of the platen 2, the energization recording head 4 is pressed against the platen 2 to perform recording.

When recording is completed, the energization recording head 4 is separated from the platen 2 in the direction of arrow A by the solenoid 9, and the conveyance of the ink ribbon 11 is stopped. The image receiving paper 3 is fed in accordance with the rotation of the platen 2, and the rear end of the image receiving paper 3 is separated from the platen 2 by a separating claw not shown.
Then, the leading end of the image receiving paper 3 is released from the grip 19 by the paper discharge guide 20, and is discharged onto the paper discharge tray 21.

FIG. 2 is a sectional view of the structure of the ink ribbon 11. As shown in FIG. 2, the ink ribbon 11 has a thickness of 12 μm in which conductive particles such as carbon black are dispersed.
In this structure, a 1 μm-thick ink layer 23 containing a sublimable coloring material is provided on a resistance layer 22 of m polycarbonate.

In the ink layer 23, a yellow ink layer 23Y containing a sublimable yellow dye, a magenta ink layer 23M containing a sublimable magenta dye, and a cyan ink layer 23C containing a sublimable cyan dye are arranged in the conveyance direction of the ink ribbon 11 (see FIG. It is applied sequentially in the opposite direction of the middle arrow C).

The length of the ink layer 23 of one color depends on the maximum length of the recording screen of the image receiving paper 3 transferred by the electric transfer printer 1, and is 55 mm. The width of the ink layer 23 is wider than the length E of the conducting portion 30 of the common electrode 7 shown in FIG.
mm.

The operation when the ink ribbon 11 is used in the energization transfer printer 1 shown in FIG. 1 will be described. As shown in FIG. 1, when the image receiving paper 3 and the yellow ink layer 23Y of the ink ribbon 11 are set at fixed positions, the solenoid 9 of the energization recording head 4 is released and the compression spring 1 is released.
0 is applied to the platen 2 in the direction of arrow B.

Then, the yellow recording signal of the read image signal is applied to the recording electrode control IC 5 of the energization recording head 4.
Then, the recording electrode control IC 5 selects a recording current and supplies the recording current to the recording electrode 6. The image receiving paper 3 is fed in accordance with the rotation of the platen 2 to finish recording the yellow image, and the energization recording head 4 is separated from the platen 2.

Then, by the same operation, a yellow image,
The cyan image is recorded, and the recording ends. FIG. 3 is a perspective view of the common electrode 7. The common electrode 7 is obtained by mechanically processing an aluminum alloy (A5052 series) and polishing the surface of the portion 30 of the ink ribbon 11 that contacts the resistance layer 22. Is formed by.

Then, masking is applied to a portion 30 (non-shaded portion in the drawing) of the ink ribbon 11 which is in contact with the resistance layer 22 and conducts, and the surface other than the masking portion (the shaded portion in the drawing and an invisible surface indicated by an arrow) The insulating film 31 is formed by subjecting the entire surface (including the entire surface) to anodic oxidation (alumite) treatment. Finally, the masking is removed, and a screw through hole 32 for fixing to the energization recording head 4 with the screw 8 is opened to obtain the common electrode 7.

Through the above steps, the surface of the common electrode 7 which is in contact with the resistance layer 22 of the ink ribbon 11 is insulated except for the conducting portion 30. If the thickness of the insulating film 31 is thin, the insulating effect will be weakened, and if it is thick, the adhesion will be poor, so a thickness of 1 to 10 μm is effective. In this embodiment, the thickness is 3 μm. In particular, when the thickness is 1 to 3 μm, a good balance between the insulating effect and the adhesiveness can be obtained.

If the width D of the conducting portion 30 is too narrow, color development occurs on the common electrode 7, and if it is too wide, the resistance layer 22 of the ink ribbon 11 can be brought into close contact with the entire width D of the conducting portion 30. Since it is difficult, about 2 mm is effective. In this embodiment, the width D of the conducting portion is 1 mm and the length E is 85 mm.
I am trying.

Since the matrix of the common electrode 7 is made of aluminum alloy, it is not necessary to use an expensive material. In addition, the thermal diffusivity is 100 to 200 as compared with resins conventionally used for the support of the common electrode, such as ABS resin and epoxy resin.
Double, non-heat swelling is 1/3 to 1/5 times, heat resistance is 3 to 5
Twice as good. Furthermore, since the heat escapes quickly and the heat storage is small, high-speed recording can be performed as compared with the conventional resin.

Further, since the insulating film 31 is formed by the surface treatment so that the coefficient of thermal expansion is almost the same, the common electrode 6 is damaged due to deformation due to thermal expansion as in the conventional case. Does not occur.

Also in terms of manufacturing, the ink ribbon 11 can be formed by the conventional method such as the attachment of the support or the embedding of the electrodes.
Although it took a lot of time and labor in the step of polishing the contact surface with the metal, the method of applying the insulating film 31 to the metal base by surface treatment is
Since the surface condition is the metal matrix itself, it is easy to manufacture.

Next, the energization recording head 4 will be described in detail. FIG. 4 is a perspective view of the electric recording head 4, and FIG. 5 is a cross-sectional view showing a cross section taken along line FF of FIG. The electric recording head 4 has an electrode pitch of 125 μm and an electrode width of 8 by forming a thin copper film having a thickness of 5 μm on the insulating flat surface of the ceramic substrate 40 having a thickness of 0.7 mm by electroless plating.
628 recording electrodes 6 of 5 .mu.m are formed, and a Ni--P alloy film is formed on the recording electrodes 6 by electrolytic plating.

The width of the ceramic substrate 40 is 100 mm so that the column length of the recording electrodes 6 is 78.5 mm. As the recording electrode control IC 5, one having 64 constant voltage drive circuits is used, and therefore the recording electrode 6 is driven by the ten recording electrode control ICs 5.

The recording electrode drive substrate 41 has an external connection terminal 4
2 is mounted and is driven at a constant voltage, and the one used in the conventional thermal head can be used. The energization recording head 4 includes a ceramic substrate 40 and a recording electrode control IC 5
And the recording electrode drive substrate 41 are supported by the aluminum support 4
It is attached by adhering it on top of the No. 3 board.

The output terminal of the recording electrode control IC 5 is connected to the rear end of the recording electrode 6 on the side opposite to the front side (the surface which contacts the resistance layer 21 of the ink ribbon 11) used for recording of the recording electrode 6 by wire bonding. Has been done. The output terminal of each recording electrode control IC 5 is connected to the external connection terminal 42 by a conductive pattern wiring provided on the plane of the recording electrode drive substrate 41.

Further, a screw through hole 44 for fixing the energization recording head 4 to the fixing base 15 with the screw 14 is provided coaxially with the recording electrode drive substrate 41 and the support body 43. Further, a screw through hole 45 for fixing the common electrode 7 to the energization recording head 4 is provided in the ceramic substrate 40, and a screw hole 46 is provided coaxially with the support body 43.

Here, the transfer of ink from the ink ribbon 11 to the image receiving paper 3 by the energization recording head 4 and the contact state between the ink ribbon 11 and the recording electrodes 6 and the common electrode 7 will be described in detail.

In FIG. 6, the common electrode 7 of FIG. 3 is mounted on the energization recording head 4 of FIG. 4, and the ink ribbon 11 and the image receiving paper 3 are urged in the direction B by the compression spring 10 to form the recording electrode 6 and the common electrode. 7 is a cross-sectional view of a state in which it is sandwiched between 7 and a platen 2. FIG.

The energization recording head 4 is attached to the fixing base 15 by screwing the screw 14 into the screw hole 47 of the fixing base 15 through the recording electrode drive substrate 41 and the screw through hole 44 of the support 43 and tightening. Has been. Common electrode 7
Is mounted on the energization recording head 4 and the ceramic substrate 4
0 through the screw through hole 45, the screw hole 46 of the support body 43,
It is attached to the energization recording head 4 with a screw 8.

FIG. 7 is an enlarged sectional view of a contact portion of the ink ribbon 11, the recording electrode 6 and the common electrode 7 in FIG. As shown in FIG. 7, the recording current flows through the path indicated by the arrow G, the common electrode 7 → the resistance layer 21 → the recording electrode 6, and the current concentrates immediately below the recording electrode 6, so that the ink in the vicinity of the recording electrode 6 is concentrated. Joule heat is generated inside the resistance layer 22 of the ribbon 11, and the ink layer 23 corresponding to the resistance layer 22 is generated.
Ink is transferred and recorded on the image receiving paper 3.

At this time, the outer side of the end portions H ₁ and H ₂ of the conducting portion 30 of the common electrode 7 contacting the resistance layer 22 of the ink ribbon 11 is electrically insulated by the insulating film 31. Since the conductive portion 30 is only the intimate contact portion on the inner side, the variation of the conductive area due to the running condition of the ink ribbon 11 does not occur, and the occurrence of discharge at the end portions H ₁ and H ₂ can be prevented.

Further, since the current does not fluctuate due to the fluctuation of the conductive area, it is possible to prevent the uneven density due to this. In this embodiment, since the thickness of the insulating film 31 is 3 μm, the resistance layer 22 of the ink ribbon 11 and the common electrode 7 are not adhered to each other, and no gap is formed to the extent that the conduction area varies.

The distance between the recording electrode 6 and the common electrode 7 is
Considering the electrode pitch of the recording electrodes 6, the electrode pitch is 50 or more.
Up to about mm is appropriate. This is because if it is less than the electrode pitch, it is difficult to manufacture, and if it exceeds 50 mm, the device and the recording head 2 become large.

In particular, when ICs are used to perform constant voltage driving with line formation, a slightly widened recording current causes interference depending on the number of recording electrodes 6 to be energized, and the recording currents are different from each other. Since density unevenness occurs because it is not evenly transmitted to, it is necessary to shorten the distance between the recording electrode 6 and the common electrode 7 to prevent density unevenness.

The common electrode 7 and the recording electrode 6 as in this embodiment.
In the structure where and are integrated, the distance between electrodes is 10 mm
It is preferably within the range. In this embodiment, the recording electrode 6
By setting the distance to 125 μm, which is the same as the electrode pitch, the recording current does not interfere and is not affected by the number of recording electrodes 6 that are energized, so that stable recording can be performed.

Further, in the conventional method as shown in FIGS. 18 and 19, the recording electrode and the common electrode facing each other are brought into planar contact with the ink ribbon, and the contact pressure of both electrodes with the ink ribbon is almost the same. In the same manner as in the present embodiment, the recording electrode 6 is in contact with the resistance layer 22 of the ink ribbon 11 at the leading edge in the electrically conductive recording head 4 having the structure in which the common electrode 7 is mounted on the recording electrode 6 as in the present embodiment. A pressing force stronger than the pressing force of the common electrode 7 can be applied to the contact point.

On the contrary, in the conducting portion 30 of the common electrode 7,
With a weaker pressing force than that of the recording electrode 6, it can be brought into close contact with the resistance layer 22 of the ink ribbon 11 without causing discharge. Therefore, a strong force is applied only to the portion to be transferred, so that higher quality recording can be performed.

Particularly, in the structure in which the common electrode 7 is mounted so that the tip of the recording electrode 6 is located before the extension line of the inclined surface of the common electrode 7 as shown in FIG. Therefore, the pressing mechanism such as the compression spring 10 and the separating mechanism such as the solenoid 9 can be downsized, and the device can be downsized.

Further, because of its structure, the tip edge portion of the common electrode 7 is not strongly pressed against the resistance layer 22 of the ink ribbon 11 and the platen 2, so that the load resistance applied to the ink ribbon 11 and the platen 2 is reduced, so that the platen 2 The life of the ink ribbon 11 can be extended, and stable conveyance of the ink ribbon 11 can be supplied.

(Second Embodiment) Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 8 shows an application example in which the position of the common electrode 7'is changed in the electro-conductive transfer printer 1 of FIGS. 6 and 7. The common electrode 7 extends beyond the extension of the inclined surface of the common electrode 7 '. The recording electrode 6 is mounted so that the tip of the recording electrode 6 is located in a non-existing area.

In this case, in order to make contact with the same contact width as in FIG. 7, a pressing mechanism for pressing the electroconductive recording head 4 to the position shown by the dotted line is required. Other than that, the same effect as the embodiment shown in FIGS. 6 and 7 can be obtained.

FIG. 9 is a sectional view showing the construction of another embodiment of the ink ribbon used in the present invention. As shown in FIG. 9, the ink ribbon 90 has a structure in which a conductive layer 91 such as aluminum having a thickness of 1000 angstrom is provided between the resistance layer 22 and the ink layer 23.

Therefore, the resistance layer 2 of the ink ribbon 90 is
When the common electrode and the recording electrode are contacted to 2 and energized, the recording current flows through the route of the common electrode → resistive layer 22 → conductive layer 91 → resistive layer 22 → recording electrode, so that the ink ribbon shown in FIG. As compared with the above, the recording current is more surely concentrated on the conductive layer 91 corresponding to the portion of the ink layer 23 to be transferred.

(Third Embodiment) Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 10 is a perspective view showing another embodiment in which the shape of the common electrode is changed. The common electrode 100 has a curvature smaller than the platen 2 on the surface of the ink ribbon 11 that contacts the resistance layer 22, and the conducting portion 30 is provided on this curved surface. The other structure and manufacturing method are the same as those of the common electrode 7 shown in FIG.

In FIG. 11, the common electrode 100 shown in FIG. 10 is mounted on the energization recording head 4 shown in FIG. 4, and the ink ribbon 11 and the image receiving paper 3 are connected to the recording electrode 6 and the common electrode 100 and the platen 2 by the compression spring 10. In the state of being sandwiched between
FIG. 3 is an enlarged cross-sectional view of a contact portion between the ink ribbon 11 and the recording electrode 6 and the common electrode 100.

Since the conducting portion 30 is provided on the curved surface of the common electrode 100 having a curvature smaller than that of the platen 2, it is different from the platen 2 in comparison with the energization recording head 4 on which the common electrode 7 having the flat surface shown in FIG. 3 is mounted. The pressing force is small, and the contact area between the common electrode 100 and the resistance layer 22 of the ink ribbon 11 is wide.

Therefore, even if the contact width fluctuates due to a malfunction of the ink ribbon 11, a non-contact portion between the conductive portion 30 and the resistance layer 22 of the ink ribbon 11 is less likely to occur, and discharge is surely prevented. Therefore, stable recording can be performed.

Also in terms of manufacturing, it is not necessary to perform the precise positioning as much as the current-carrying recording head 4 having the common electrode 7 mounted thereon. Other effects can be the same as those of the embodiment shown in FIGS.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. FIG. 12 is a cross-sectional view showing another embodiment in which the shape of the common electrode is changed, and is the same as that of the first embodiment (FIG. 6) except that the common electrode 120 is mounted on the electric recording head 4 shown in FIG. Since the configurations are the same, the description is omitted.

As shown in FIG. 12, the common electrode 120 is
The common electrode 12 in contact with the resistance layer 22 of the ink ribbon 11.
In this structure, the contact surface 30 'of 0 is projected to insulate the surface of the common electrode 120 outside the end of the contact surface 30'.
Therefore, the surface of the common electrode 120 in contact with the resistance layer 22 of the ink ribbon 11 is a conductive portion, and the conductive area is constant.

Here, even if a trouble occurs in the running of the ink ribbon 11, for example, slack occurs, no discharge occurs because the conductive area of the common electrode 120 does not change because the parts other than the conductive part 30 'are insulated. Since the matrix of the common electrode 120 is smaller than that of the common electrodes 7 and 100 of FIGS. 3 and 10, the device is inexpensive. Common electrode 1 to recording electrode 6
With respect to the mounting position of 20, the pressing relationship between the recording electrode 6 and the common electrode 7, and the like, the same effects as those of the common electrodes 7 and 7'in FIGS. 7 and 8 can be obtained.

(Fifth Embodiment) Next, a fifth embodiment of the present invention will be described with reference to FIG. 13 is the same as that of the conventional technique (FIG. 17) except for the common electrode shaft 134, the description thereof will be omitted.

The common electrode shaft 134 is the ink ribbon 1
The outer side of the end portion J of the contact portion of the common electrode shaft 134 that contacts the first resistance layer 22 is insulated. for that reason,
Even if slack occurs due to a trouble in running the ink ribbon 11, the conductive area of the common electrode 134 does not change, so that no discharge occurs.

Further, since the insulation is performed by the surface treatment, there is no thickness that hinders the conveyance of the ink ribbon 11, so that stable recording can be performed. 14 and 15 are cross-sectional views showing a state in which the ink ribbon 11 and the image receiving paper 3 are sandwiched between the recording electrode 6 and the common electrode 7 and the platen 2, and the conductive portion 30 side of the common electrode 7 shown in FIG. Consider the relationship between the inclination angle α and the size of the platen 2.

The plane of the conducting portion 30 of the common electrode 7 is the platen 2
Touches perpendicularly (or substantially perpendicularly) to the radial direction of. The tip R of the recording electrode 6 does not contact perpendicularly to the radial direction of the platen 2. The dotted line is the tip R of the recording electrode 6.
Represents a plane perpendicular to the radial direction of the platen 2 at, and the point where this dotted line intersects the common electrode is Q.

At this time, the angle formed by the plane of the recording head 4 and the dotted line is β _1, and the angle formed by the center point P of the contact surface of the common electrode 7, the center point O of the platen 2 and the tip R of the recording electrode 6 is defined. Let γ ₁ .

Here, the inclination angle α of the common electrode 7 on the conducting portion 30 side has a relationship of α = β ₁ + γ ₁ = β ₁ + PR / u _{1 when} the radius of the platen is u ₁ .

When the inclination angle α is larger than β ₁ + γ ₁ ,
The common electrode 7 comes into contact first, and the tip portion R of the recording electrode 6
Cannot be sufficiently pressed against the resistance layer 22 of the ink ribbon 11. Further, if the inclination angle α is smaller than β ₁ + γ ₁ , there is a problem that the conducting portion 30 of the common electrode 7 cannot be sufficiently contacted.

Next, consider the deformation amount δ of the platen 2 when the common electrode 7 is pressed against the platen. In FIG. 15, the image receiving paper 3 and the ink ribbon 11 are omitted for clarity.

The ends of the contact surface of the common electrode 7 that contacts the platen 2 are designated as R and S, respectively. Conducting part 3 of common electrode 7
Since the width D of 0 is 1 mm, the distance between R and S is at least 1
must be greater than mm.

The center point P of the contact surface of the common electrode 7 when the common electrode 7 and the recording electrode 6 are brought into contact with the platen 2 having the radius u ₂
From the contact point to the edge S or R of the contact surface is a, and the angle between the point P, the center point O of the platen 2 and the edge S of the contact surface of the common electrode 7 is γ ₂ , then γ ₂ = sin ⁻¹ (a / u ₂ ), where the units of the angles γ ₂ and β ₂ are radians and 0.
If the angle is very small, less than 1 radian, Becomes

Next, the apex of the platen 2 when it is not deformed to the position of the center point P of the contact surface of the common electrode 7 is T. A conductive portion 30 plane of the common electrode 7 and the angle formed between the end portion S and the vertex T of the platen 2 in the contact surface and beta _2, since the triangle OST is isosceles _{triangle, β 2 = γ 2/2} = a / 2 u ₂ , and the deformation amount δ of the platen 2 is calculated as follows. From the triangle PST, δ ≧ a · tan β ₂ ≧ a · tan (a / 2u ₂ ) ≧ a ² / 2u ₂ .

Accordingly, for example, the platen 2 having a radius of 10 mm has at least 1 mm of the width D of the conducting portion 30 of the common electrode 7.
When they are brought into contact with each other, the platen 2 is deformed by about 12.5 μm. In other words, a pressing mechanism that can deform the platen 2 by at least 12.5 μm or more is required.

Next, consider the deformation amount δ of the platen 2 in the case of the common electrode 7'shown in FIG. FIG. 16A is a cross-sectional view showing a state in which the ink ribbon 11 and the image receiving paper 3 are sandwiched between the common electrode 7'having a radius of curvature u ₄ and the platen 2 having the radius u ₃ of the recording electrode 6. Receiving paper 3 for clarity
The ink ribbon 11 is omitted.

Here, the center point P ′ of the contact surface of the common electrode 7 ′ is perpendicular to the radial direction of the platen 2. The end portions of the contact surface of the common electrode 7'contacting the platen 2 are designated as R'and S ', respectively. The platen 2 when not deformed by δ to the position of the center point P'of the contact surface of the common electrode 7 '
Let T'be the vertex of.

The width D of the conducting portion 30 of the common electrode 7'is 1 mm.
Therefore, at least the R ', P', and S'curved surfaces are 1 mm or more. Here, the curve from the center point P'of the contact surface of the common electrode 7'to the contact surface end S'or R'is a '.

FIG. 16 (b) is an enlarged cross-sectional view of the portion connecting the T'-S 'curve, the radius of curvature O'of the common electrode 7'and the end S'of the contact surface. In the following, the description will be omitted when it can be derived by the same method as in FIG.

The angle formed by the center P'of the contact surface of the common electrode 7 ', the center O of the platen 2 and the end S'of the contact surface of the common electrode 7'is γ ₃ . If the angle formed by the center P ′ of the contact surface of the common electrode 7 ′, the center of curvature O ′ of the curved surface of the common electrode 70, and the end S ′ of the contact surface is γ ₄ , Becomes Further, when the angle formed by the platen 2 'and the common electrode 7' vertex T and radially OT 'perpendicular to the plane of the platen 2 including the end portion S' and the end portion S 'of the contact surface of the beta _3, beta ₃ = the γ _3/2. When the angle formed between the plane perpendicular to the radial direction of the platen 2 including the end portion S of the contact surface 'and the end portion S''center P of the contact surface of' the common electrode 7 and β _4, β ₄ = γ ₄ It becomes / 2. Here, the unit of the angles γ ₃ , γ ₄ , β ₃ , and β ₄ is radian, which is a minute angle of 0.1 radian or less.

If the intersection of the plane perpendicular to the radial direction OT 'of the platen 2 including the end S'and the radius OT' of the platen 2 is U and the length is b, Therefore, γ ₃ = sin ⁻¹ (b / u ₃ ) = a ′ / u ₃ . Therefore, the deformation amount δ of the platen 2 becomes δ ≧ a ′ ² / 2u ₃ −a ′ ² / 2u _{4 due} to δ ≧ b (tan β ₃ −tan β ₄ ).

When the platen 2 having a radius of 10 mm is touched by 1 mm of the width D of the conducting portion 30 of the common electrode 7 ', the platen 2 is deformed by 3.75 μm. As compared with the deformation amount of 12.5 μm in the case of the common electrode 7 of FIG. 3, when the same conduction width of 1 mm is contacted, the common electrode 7 ′ of FIG. 2 can be contacted.

The thickness of the insulating film 31 formed by the surface treatment is 3
Since it is μm, the radius of curvature u ₄ of the common electrode 7 ′ is
When the radius is close to the radius u ₃ of the common electrode 7 ′,
First, the ink ribbon 1 is formed on the insulating film 30 on the outer side of the ink ribbon 1.
There is a possibility that the first resistance layer 22 contacts, and in this case, the area of the conducting portion 30 of the common electrode 7 ′ that contacts the platen 2 decreases.

Therefore, the conducting portion 30 of the common electrode 7'needs to come into contact with the resistance layer 22 of the ink ribbon 11 before or at the same time as the insulating film 31. That is, when the thickness of the insulating film 31 is t ₄ , the ink ribbon must enter the curved surface of the insulating film 31 by t ₅ (t ₅ ≧ t ₄ ) at the time of starting contact with the common electrode.

Therefore, in order to obtain the radius of curvature u ₄ of the common electrode by the above equation, the thickness t ₃ of the image receiving paper 3 and the ink ribbon 11 is added to the radius u _{3 of the} platen 2 to obtain the thickness of the insulating film. is' subtracted from the curvature radius u ₄ of, t ₅ ≧ a 'to t ₄ common electrode 7 is required to satisfy the _{^{2/2 (u 3 + t}} 3) -a' 2/2 (u 4 -t 4) . Therefore, the radius of curvature u _{4 of the} common electrode
Is u ₄ ≧ a ′ ² (u ₃ + t ₃ ) / {a ′ ² −2t ₅ (u ₃ + t ₃ )} + t ₄ . Further, since at least t ₅ = t ₄ , it suffices that u ₄ ≧ a ′ ² (u ₃ + t ₃ ) / {a ′ ² −2t ₄ (u ₃ + t ₃ )} + t ₄ . Therefore, the radius of curvature l ₄ of the common electrode 7 ′ shown in FIG. 10 can be determined with reference to the above equation.

[0096]

As described above, according to the present invention, since the end portion of the contact surface of the common electrode that contacts the resistance layer of the ink ribbon is insulated, the conductive area of the common electrode does not change, and thus the printing is performed. Occurrence of discharge can be prevented. Therefore, uneven density due to abrasion of the electrodes or cutting of the ink ribbon does not occur, and durable high-quality transfer recording is possible.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment of an electric transfer recording apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of an ink ribbon.

FIG. 3 is a perspective view of a common electrode.

FIG. 4 is a perspective view of an electric recording head.

FIG. 5 is a cross-sectional view of an electric recording head.

FIG. 6 is a cross-sectional view showing the main parts of the recording apparatus.

FIG. 7 is an enlarged cross-sectional view of the common electrode and the vicinity of the leading end of the electric recording head.

FIG. 8 is an enlarged cross-sectional view showing a second embodiment of the common electrode.

FIG. 9 is a cross-sectional view showing the structure of another embodiment of the ink ribbon.

FIG. 10 is a perspective view showing a third embodiment of the common electrode.

FIG. 11 is a sectional view showing a third embodiment of the common electrode.

FIG. 12 is a cross-sectional view showing a fourth embodiment of a common electrode.

FIG. 13 is a sectional view showing a fifth embodiment of a common electrode.

FIG. 14 is a cross-sectional view showing the relationship between the tilt angle of the common electrode and the radius of the platen.

FIG. 15 is a cross-sectional view showing the amount of deformation of the platen.

FIG. 16 is a cross-sectional view showing the amount of deformation of the platen in the case of a common electrode having a curvature.

FIG. 17 is a structural diagram of a conventional recording electrode and a common electrode.

FIG. 18 is a structural diagram of a conventional recording electrode and a common electrode.

FIG. 19 is a structural diagram of a conventional recording electrode and a common electrode.

[Explanation of symbols]

 2 platen 3 image receiving paper 4 energization recording head 5 recording electrode control IC 6 recording electrode 7, 7 ', 100, 120, 134 common electrode 9 solenoid 10 compression spring 11, 90 ink ribbon 22 resistance layer 23 ink layer 30 conduction part 31, 135 insulating film

Claims (7)

[Claims] 1. An ink ribbon comprising an ink layer having a color material transferred to a transfer paper and a resistance layer for generating heat when energized to transfer the color material of the ink layer to the transfer paper, and the ink. A transport means for transporting the ribbon together with the transfer paper, a recording electrode in contact with the resistance layer of the ink ribbon, and a contact with the resistance layer of the ink ribbon at a position different from the contact position of the recording electrode and the ink ribbon. Then, a common electrode that is electrically connected to the recording electrode with a predetermined width in the ink ribbon transport direction, and the common electrode and the ink ribbon that are provided on the surface of the common electrode outside the conduction portion in the ink ribbon transport direction are provided. And an insulating means for insulating the surface of the common electrode so as not to come into contact with each other with a width equal to or larger than the width. 2. An ink ribbon comprising an ink layer having a color material to be transferred to a transfer paper and a resistance layer for generating heat by being energized to transfer the color material of the ink layer to the transfer paper, and the ink. A transport means for transporting the ribbon together with the transfer paper, a recording electrode in contact with the resistance layer of the ink ribbon, and a resistance layer of the ink ribbon and ink in a position on a plane different from the position where the recording electrode and the ink ribbon contact. And a common electrode formed in a shape such that the ribbon is in contact with a predetermined width in the transport direction and the ink ribbon is not in contact with the common electrode outside the contact portion in the transport direction of the ink ribbon. Electric transfer recording device. 3. The common electrode is formed in a convex shape so that the convex protruding portion is in contact with the resistance layer of the ink ribbon, and all the surfaces of the convex protruding portion are formed of the ink ribbon. 3. An electric transfer recording apparatus according to claim 2, further comprising means for urging the common electrode against the ink ribbon so as to come into contact with the resistance layer. 4. The electric transfer recording according to claim 3, wherein the convex protruding portion of the common electrode is provided with an insulating means for insulating the outer surface of the contact portion which comes into contact with the resistance layer of the ink ribbon. apparatus. 5. An ink ribbon comprising an ink layer having a coloring material transferred to a transfer paper and a resistance layer for generating heat by being energized to transfer the coloring material of the ink layer to the transfer paper is energized. In the energization transfer recording head, a recording electrode that is in contact with the resistance layer of the ink ribbon and a surface that is provided on the recording electrode and that is inclined with respect to the recording electrode are provided. A common electrode that contacts with a predetermined width in the ribbon transport direction, and the surface of the common electrode that is provided on the surface of the common electrode so that the common electrode and the ink ribbon do not contact outside the contact portion in the ink ribbon transport direction. An electrically conductive transfer recording head, comprising: 6. The common electrode is provided on the recording electrode such that a tip portion of the recording electrode is located in front of an extension line of an inclined surface of the common electrode. Energization transfer recording head. 7. A platen roller forms an ink ribbon composed of an ink layer having a color material transferred to a transfer paper and a resistance layer for generating heat when energized to transfer the color material of the ink layer to the transfer paper. A recording electrode for contacting with the resistance layer of the ink ribbon and sandwiching the ink ribbon with the platen roller, in an energization transfer recording head for energizing the ink ribbon as it is conveyed, Has a curved surface having a curvature smaller than that of the platen roller, and contacts the resistance layer of the ink ribbon with a predetermined width in the transport direction of the ink ribbon on the curved surface and sandwiches the ink ribbon with the platen roller. The common electrode and the common electrode provided on the surface of the common electrode and the ink ribbon are arranged in the ink ribbon transport direction. And an insulating means for insulating the surface of the common electrode so as not to make contact with the outside of the contact portion.