JPH05345436A - Heat recording film head - Google Patents

Abstract

PURPOSE:To prevent the variation of printing density and the generation of uneven printing because of the voltage drop generated by the internal resistance of a common electrode correspondingly to the numbers of heating resistance elements developing heat simultaneously. CONSTITUTION:A through-hole 118 running through a substrate layer 1020, a heat dissipating layer 120 and a heat insulated layer 103 is formed in a heat recording film head, on which a heating resistance element 104 and a couple of electrodes 105a and 105b crossing the heating resistance element are formed in a row, on a component of a structure consisting of heat dissipating layer 120 of high heat conductivity and high electrical conductivity and a heat insulated layer 103 of low heat conductivity and insulated electrically, bonded and laminated over the heat insulated layer on the flexible substrate layer 102. The inner wall of the hole 118 and the outlet periphery of the hole are coated by a conductive material 119, and a common electrode 105a on the power supply side for applying the electric current to the heat dissipating layer 120 and the heating resistance element 104 is conducted through the conductive material 119.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal recording apparatus by a method of heating an ink sheet to transfer ink to a recording paper or a method of directly heating a thermal paper to develop a color for recording, and a copying machine using the same. The present invention relates to a thermal recording film head used in a recording device such as a facsimile, a printer and a word processor.

[0002]

2. Description of the Related Art A thermal recording method involves heating an ink sheet,
Recording is performed by transferring ink to a recording paper or by directly heating a thermal paper to develop a color.

A conventional thermal transfer recording method using an ink sheet will be described with reference to the drawings. FIG. 6 is a side view of a thermal transfer recording apparatus using a conventional flat type thermal recording head (thermal head), and FIG. 7 is a side view of a conventional thermal recording head.

First, a conventional flat-type thermal recording head will be described with reference to FIG. In the figure, 201 is a planar thermal recording head using a planar substrate. In the flat-type thermal recording head 201, a heat insulating layer 203 made of glass is provided on a support substrate 202 made of alumina, and a heating resistor 204 and a heating resistor 204 are sandwiched by using a thin film or thick film technique. A pair of electrodes 205a and 205b are formed in a row. Here, 205a is a common electrode on the supply side, 2
Reference numeral 05b is a return-side individual electrode.

The return-side individual electrodes 205b are connected together to the gates of a plurality of driving semiconductor elements (ICs) 214 in a certain number. Due to this switching of the driving IC 214, the current from the common electrode 205a on the supply side flows through the heating resistor 204 to generate heat.

On the heating resistor 204, an oxidation resistant film is formed in order to prevent oxidation of the heating resistor 204 and an abrasion resistant layer 207 is sequentially formed to prevent abrasion by the ink sheet.

In a thermal transfer recording apparatus using this head, as shown in FIG. 6, a recording paper 208 is a recording paper cassette 209.
The sheet is fed by the sheet feeding roller 210 from the flat type thermal recording head 201 to the platen roller 211. The ink sheet 212 and the recording sheet 208 are pressed against each other by the thermal recording head 201 and the platen roller 211, and the heat of the heating resistor 204 transfers the ink of the ink sheet 212 onto the recording sheet. In parallel with this operation, since the recording paper 208 is conveyed by the platen roller 211, an image is recorded on the recording paper 208. Then, when recording is completed, the recording paper 208 is discharged by the discharge rollers 213a and 213b.
Is discharged. 223a and 223b are platen pinch rollers.

Next, the energization of these thermal transfer recording devices will be described. FIG. 13 shows an equivalent circuit of the thermal recording head. In FIG. 13, Ra is the common electrode 205 on the supply side.
a is the internal resistance, Rb is the internal resistance of the individual electrode connected to each heating resistor 204, Rc is the resistance of the heating resistor 204, Rd
Is the internal resistance of the driving IC 214, and Re is the internal resistance of the return-side common electrode 205c. Ii is current. The relationship between each resistance and voltage can be expressed as shown in the following mathematical formula 1.

[0009]

[Formula 1]

As shown in the equation (1), when the number n of the heating resistors 204 simultaneously energized increases, the voltage drop at the internal resistance Ra of the supply side common electrode 205a and the internal resistance Re of the return side common electrode 205c becomes large. Becomes, heating resistor 20
The voltage applied to 4 becomes small, and the amount of heat generation becomes small. In fact, the return-side common electrode 205c is short, so its influence is small.

For this reason, when the area of the image to be printed is large and the number of heating resistors simultaneously energized is large, the heating value of each heating resistor is smaller than that in the opposite case, and The image density decreases.

In order to solve this problem, a reinforced common electrode 205a on the supply side as shown in FIGS. 9 and 10 has been put into practical use. That is, the flexible substrate 2
A semiconductor layer 205d is formed on the conductive layer 205d, and the formed conductor layer 205d is short-circuited with the supply-side common electrode 205a and connected to the connector 216. Then, as shown in FIG. 10, the resistance value is reduced and the voltage drop is reduced by widening the width of the conductor layer 205d.

However, in this structure, the width of the conductor layer 205d is limited for the convenience of mounting the head support member 217, and the flexible substrate 21 is also limited.
5 had to be joined to the head supporting substrate 202, which had a drawback that the manufacturing became complicated.

Further, Japanese Patent Laid-Open No. 4-80051 discloses a method as shown in FIGS. 11 and 12.

This is provided with a heat storage layer 303, a plurality of heat generating resistors 304 on a heat resistant resin substrate 302, and a driver IC 314 for controlling energization of the heat generating resistors 304. A plurality of common electrodes are provided on the resin substrate 302, and one of the common electrodes for mounting a heat generating resistor has a heat storage layer 303 also serving as an insulating layer and a heat generating resistor 304 on the upper surface. It is provided. The common electrode 305a is connected to the heating resistor 304 by the wiring electrode 305d through the contact hole 318 formed in the heat storage layer 304, and the remaining common electrode 305e.
Is connected to the heating resistor 304 by a wiring electrode 305d in an insulated state from the heating resistor mounting common electrode 305,
Each heating resistor 304 is connected to the driver IC 314 by a signal electrode 305b. This wiring electrode 30
5d and the signal electrode 305b are patterned in the same step.

[0016]

However, in this method, the contact hole 318 must be formed after forming the heating resistor mounting electrode 305a.
The process becomes complicated. In order to connect the wiring electrode 305d and the heating resistor mounting electrode 305a through the contact hole 318, it is necessary to surely inject and fill the inside of the contact hole 318 with a conductor. There is a problem in that it is difficult and completely unreliable to completely fill the product because air is present inside.

The present invention solves the above-mentioned conventional problems, and because of the voltage drop due to the internal resistance of the common electrode, the printing density changes depending on the number of heat-generating resistors that simultaneously generate heat. It is an object of the present invention to improve the deterioration of image quality, which causes unevenness of image formation, without depending on a complicated structure, and by sufficiently increasing the effect.

[0018]

A first thermal recording film head according to the present invention comprises a flexible support layer, a heat dissipation layer having high heat conductivity and high conductivity, and a heat conductivity layer formed thereon. Film head for heat recording, in which a heat-generating resistor and a pair of electrodes sandwiching the heat-generating resistor are formed in a row on a member having a structure in which heat-insulating layers that are low in temperature and are electrically insulating In, the support layer, the heat dissipation layer, and has a hole penetrating the heat insulating layer, the inner wall of the hole and the periphery of the outlet of the hole are covered or filled with a conductor, and the heat dissipation layer is formed through the conductor. At least one of a supply-side common electrode for supplying a current to the heating resistor or a return-side common electrode to which a current flowing out of the heating resistor joins is made conductive.

The second thermal recording film head of the present invention comprises a flexible support layer, a heat dissipation layer having high heat conductivity and high conductivity, and a heat dissipation layer having low heat conductivity and being electrically insulated on the heat dissipation layer. In a thermal recording film head in which a heat-generating resistor and a pair of electrodes sandwiching the heat-generating resistor are formed in a row on a member having a structure in which the heat-insulating layer is in close contact and overlaps, A part is exposed from the heat insulating layer and is electrically connected to at least one of the supply side common electrode and the return side common electrode.

[0020]

According to the present invention, the combined current passing through the common electrode flows into the heat dissipation layer. Since the heat dissipation layer has a sufficient cross-sectional area and the resistance value is very small, there is almost no voltage drop here even if the number of resistors that simultaneously generate heat is large.
Therefore, the print density does not change due to the voltage drop due to the internal resistance of the common electrode, and high-quality recording can be performed.

[0021]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of an apparatus showing an embodiment using the thermal recording film head of the present invention. 2 is a side sectional view of a film head showing the first embodiment of the present invention, and FIG. 3 is a bottom view thereof. FIG. 4 is a side sectional view of a film head showing a second embodiment of the present invention, and FIG. 5 is a bottom view thereof.

The first thermal recording film head of the present invention will be described with reference to FIGS. In the figure, 101 is an end face type thermal recording head having a structure in which a film head 121 is fixed to the surface of a film head support 117. The film head 121 is shown in FIGS.
As shown in, a heat-dissipating layer 120 and polybenzimidazole, which are formed by copper plating or copper foil adhesion and have good thermal conductivity and high conductivity, are formed on a flexible support layer 102 such as polybenzimidazole or polyimide. A heat insulating layer 103 such as polyimide having heat resistance, low heat conductivity and electrical insulation is provided, and a heat generating resistor 104 and a pair of electrodes 105a sandwiching the heat generating resistor 104 are formed thereon by using a thin film or thick film technique. 105b are formed in rows.

Reference numeral 105a is a supply side common electrode, 105b is a return side individual electrode, and 105c is a return side common electrode. In order to control the current to the heating resistor 104, a driving IC 114 is connected on the return path side.

Further, in order to prevent oxidation and wear of the heating resistor 104, an oxidation resistant film 106 is formed on the heating resistor.
And the abrasion resistant layer 107 is formed.

In this first embodiment, the support layer 10
After the heat dissipation layer 120 and the heat retention layer 103 are formed on the second layer,
A plurality of through-holes 118 are opened in a position corresponding to the supply-side common electrode 105a, and the inner wall of the through-hole and the periphery of the outlet of the hole are plated 119.

After that, the heating resistor 104 is formed, and the supply side and return side electrodes 105a, 105b, 105 are formed thereon.
c is formed, and at the same time, other conductive wires are formed by patterning. At this time, the common electrode 105a on the supply side is electrically connected to the plating 119 around the exit of the through hole 118. Since the plating 119 on the inner wall of the through hole 118 and the cross section of the heat dissipation layer 120 are electrically connected, the supply-side common electrode 105
The a is electrically connected to the heat dissipation layer 120.

Further, the heat dissipation layer 120 has a connector 116.
Are connected by through holes in the same manner as described above, and a current flows through the heat dissipation layer 120 to the heating element 104. As a result, there is no need to run the wires from the connector 116, and there is almost no voltage drop due to the large cross-sectional area of the heat dissipation layer 104.

On the return path side, since the distance from the driving IC 114 to the connector 116 is short, the voltage drop at the return path common electrode 105c is small. An insulating layer 121 is formed on the electrodes.

As described above, the merged currents passing through the common electrodes 105a and 105b flow into the heat dissipation layer 120. Since the heat dissipation layer 120 has a sufficient cross-sectional area and the resistance value is very small, there is almost no voltage drop here even if the number of resistors that simultaneously generate heat is large.

In the above embodiment, the through hole 1
Although the inner wall of 18 and the periphery of the outlet are covered with plating 119, the inside of the through hole 118 may be filled with a conductive material so that the supply-side electrode 105 a and the heat dissipation layer 120 are electrically connected.

Next, the second embodiment will be described with reference to FIGS.
Will be described. Also in the second embodiment, the heat dissipation layer 120 is formed on the support layer 102 in the same manner as the first embodiment. After that, the heat insulation layer 103 is formed thereon so that a part of the heat dissipation layer 120 on the supply side is exposed.

After forming the heating resistor 104, the electrode layers 105a, 105b and 105c are formed.
At this time, the heat dissipation layer 12 in which the supply-side common electrode 105a is exposed
Joined with 0.

Further, the heat dissipation layer 120 is connected to the connector 116 by a through hole as in the first embodiment, and the heat dissipation layer 1
An electric current flows through the heating element 104 through 20. Connector 1
There is no need to run the wires from 16, and there is almost no voltage drop due to the large cross-sectional area of the heat dissipation layer 120.

On the return path side, since the distance from the driving IC 114 to the connector 116 is short, the return path common electrode 105
The voltage drop at c is small.

An insulating layer 122 is formed on the electrodes as in the first embodiment.

Next, the printing operation of the thermal transfer recording apparatus to which the thermal recording film head according to the present invention is applied will be described with reference to FIG. The recording paper 108 is fed from the recording cassette 109 by the paper feed roller 110, and the platen roller 1
11 and the platen pinch roller 123a, and is conveyed between the end face type thermal recording film head 101 according to the present invention and the platen roller 111. Then, the ink sheet 112 and the recording paper 108 are pressed against each other by the end face type thermal recording film head 101 and the platen roller 111, and the heat generated by the heating resistor 104 causes the ink sheet 11 to come into contact.
The second ink is transferred to the recording paper 108. Since the recording paper 108 is conveyed by the platen roller 111 in parallel with this operation, an image is recorded on the recording paper 108. When recording is completed, the platen roller 111 and the platen pinch roller 12
The recording paper 108 is ejected by the paper ejection rollers 113a and 113b through 3b.

[0037]

As described above, according to the present invention, since the resistance of the common return electrode is very small, the voltage applied to the heating resistors fluctuates depending on the number of resistors that simultaneously generate heat. Since there is almost no image density unevenness in which the density varies depending on the size of the image to be printed, high image quality can be realized.

[Brief description of drawings]

FIG. 1 is a side view of an apparatus using a thermal recording film head of the present invention.

FIG. 2 is a side sectional view of the first embodiment of the thermal recording film head of the present invention.

FIG. 3 is a bottom view of the first embodiment of the thermal recording film head of the present invention.

FIG. 4 is a side sectional view of a second embodiment of the thermal recording film head of the present invention.

FIG. 5 is a bottom view of the second embodiment of the thermal recording film head of the present invention.

FIG. 6 is a side view of an apparatus using a conventional thermal recording head.

FIG. 7 is a side sectional view of a conventional thermal recording head.

FIG. 8 is a bottom view of a conventional thermal recording head.

FIG. 9 is a side sectional view of a conventional thermal recording head.

FIG. 10 is a bottom view of a conventional thermal recording head.

FIG. 11 is a side sectional view of a conventional thermal recording head.

FIG. 12 is a bottom view of a conventional thermal recording head.

FIG. 13 is an equivalent circuit of a thermal recording head.

[Explanation of symbols]

 Reference Signs List 101 end face type thermal recording head 102 support layer 103 heat retaining layer 104 heating resistor 105a supply side common electrode 105b return side individual electrode 105c return side common electrode 106 oxidation resistant film 107 abrasion resistant layer 108 recording paper 109 recording paper cassette 110 paper feeding Roller 111 Platen roller 112 Ink sheet 113a Paper discharge roller 113b Paper discharge roller 114 Driving IC 116 Connector 117 Head support member 118 Through hole 119 Plating 120 Heat dissipation layer 121 Film head 122 Insulation layer 123 Platen pinch roller

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] April 14, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction content]

On the heating resistor 204, an oxidation resistant film 206 is formed in order to prevent oxidation of the heating resistor 204, and an abrasion resistant layer 207 is sequentially formed to prevent abrasion by the ink sheet.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

In a thermal transfer recording apparatus using this head, as shown in FIG. 6, a recording paper 208 is a recording paper cassette 209.
The sheet is fed by the sheet feeding roller 210 from the flat type thermal recording head 201 to the platen roller 211. The ink sheet 212 and the recording sheet 208 are pressed against each other by the thermal recording head 201 and the platen roller 211, and the heat of the heating resistor 204 transfers the ink of the ink sheet 212 onto the recording sheet. In parallel with this operation, since the recording paper 208 is conveyed by the platen roller 211, an image is recorded on the recording paper 208. Then, when recording is completed, the recording paper 208 is discharged by the discharge rollers 213a and 213b.
Is discharged. Incidentally, 123a and 123b are platen pinch rollers.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

Next, the energization of these thermal transfer recording devices will be described. FIG. 13 shows an equivalent circuit of the thermal recording head. In FIG. 13, Ra is the common electrode 205 on the supply side.
a is the internal resistance, Rb is the internal resistance of the individual electrode connected to each heating resistor 204, Rc is the resistance of the heating resistor 204, R
d is the internal resistance of the driving IC 214, and Re is the internal resistance of the return-side common electrode 205c. Ii is current. The relationship between each resistance and voltage can be expressed as shown in the following mathematical formula 1.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

[0009]

[Formula 1]

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

In order to solve this problem, a reinforced common electrode 205a on the supply side as shown in FIGS. 9 and 10 has been put into practical use. That is, the flexible substrate 2
A conductor layer 205d is formed on the electrode 15, and the formed conductor layer 205d is short-circuited with the supply-side common electrode 205a and connected to the connector 216. Then, as shown in FIG. 10, the resistance value is reduced and the voltage drop is reduced by widening the width of the conductor layer 205d.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

This is provided with a heat storage layer 303, a plurality of heat generating resistors 304 on a heat resistant resin substrate 302, and a driver IC 314 for controlling energization of the heat generating resistors 304. A plurality of common electrodes are provided on the resin substrate 302, and one of the common electrodes for mounting a heating resistor has a heat storage layer 303 also serving as an insulating layer and a heating resistor 304 on the upper surface. It is provided. The common electrode 305a is connected to the heating resistor 304 by the wiring electrode 305d through the contact hole 318 formed in the heat storage layer 304, and the remaining common electrode 305e.
Are connected to the heating resistors 304 by the wiring electrodes 305d in a separated state from the heating resistor mounting common electrode 305a, and each heating resistor 304 is connected to the driver IC 314 by a signal electrode 305b. The wiring electrode 305d and the signal electrode 305b are patterned in the same step.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

[0018]

A first thermal recording film head according to the present invention comprises a flexible support layer, a heat dissipation layer having high heat conductivity and high conductivity, and a heat conductivity layer formed thereon. Film head for heat recording, in which a heat-generating resistor and a pair of electrodes sandwiching the heat-generating resistor are formed in a row on a member having a structure in which heat-insulating layers that are low in temperature and are electrically insulating In, the support layer, the heat dissipation layer, and has a hole penetrating the heat insulating layer, the inner wall of the hole and the periphery of the outlet of the hole are covered or filled with a conductor, and the heat dissipation layer is formed through the conductor. At least one of a supply-side common electrode for supplying a current to the heating resistor and a return-side common electrode to which a current flowing out of the heating resistor joins is made conductive.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0022

[Correction method] Change

[Correction content]

The first thermal recording film head of the present invention will be described with reference to FIGS. In FIG. 1, reference numeral 101 denotes an end face type thermal recording head having a structure in which a film head 121 is fixed to the surface of a film head support 117. As shown in FIGS. 2 and 3, the film head 121 is formed by copper plating or copper foil bonding on a flexible support layer 102 such as polybenzimidazole or polyimide, and has good thermal conductivity. Heat-dissipating layer 120 having high heat resistance and heat-insulating layer 103 such as polybenzimidazole, polyimide, etc., which has heat resistance, low heat conductivity and is electrically insulating, are provided thereon, and a thin film or thick film technology is used to generate a heat-generating resistor. 104 and a pair of electrodes 105a and 105b sandwiching the same 104 are formed in a row.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

Reference numeral 105a is a supply-side common electrode, 105b is a return-side individual electrode, and 105c is a return-side common electrode. In order to control the current to the heating resistor 104, a driving IC 114 is connected on the return path side.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

On the return path side, since the distance from the driving IC 114 to the connector 116 is short, the voltage drop at the return path common electrode 105c is small. An insulating layer 122 is formed on the electrodes.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] Explanation of code

[Correction method] Change

[Correction content]

[Explanation of reference numerals] 101 end face type thermal recording head 102 support layer 103 heat retaining layer 104 heating resistor 105a supply side common electrode 105b return side individual electrode 105c return side common electrode 106 oxidation resistant film 107 abrasion resistant layer 108 recording paper 109 recording Paper cassette 110 Paper feed roller 111 Platen roller 112 Ink sheet 113a Paper ejection roller 113b Paper ejection roller 114 Driving IC 116 Connector 117 Head support member 118 Through hole 119 Plating 120 Heat dissipation layer 121 Film head 122a Insulation layer 123b Platen pinch roller

[Procedure Amendment 12]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

[Figure 1]

[Procedure Amendment 13]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 7

[Correction method] Change

[Correction content]

[Figure 7]

[Procedure Amendment 14]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Change

[Correction content]

[Figure 10]

[Procedure Amendment 15]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 11

[Correction method] Change

[Correction content]

FIG. 11

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Satoshi Kuwahara 2-18 Keihan Hondori, Moriguchi City Sanyo Electric Co., Ltd.

Claims (2)

[Claims] 1. A structure in which a heat dissipation layer having a high heat conductivity and a high conductivity and a heat insulation layer having a low heat conductivity and an electrical insulation are closely adhered and overlapped on a flexible support layer. In a film head for thermal recording in which a heating resistor and a pair of electrodes sandwiching the heating resistor are formed in a row on a member having, a penetrating through the supporting layer, the heat radiating layer, and the heat retaining layer. The inner wall of the hole and the periphery of the outlet of the hole are covered or filled with a conductor, and a current is supplied to the heat dissipation layer and the heat generating resistor through the conductor. A film head for thermal recording, wherein at least one of the common electrodes on the return path where the current flowing out of the body joins is made conductive. 2. A structure in which a heat dissipation layer having high heat conductivity and high conductivity and a heat insulation layer having low heat conductivity and electrical insulation are closely adhered and overlapped on a flexible support layer. In a film head for thermal recording in which a heating resistor and a pair of electrodes sandwiching the heating resistor are formed in a row on a member having, a part of the heat dissipation layer is exposed from the heat retaining layer, A film head for thermal recording, which is electrically connected to at least one of the supply-side common electrode and the return-side common electrode.