JP5340094B2 - Recording head and recording apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a recording head capable of suppressing printing blur and a recorder. <P>SOLUTION: A spacer particle 19 coming into contact with a head base body 10 and a radiator 40 with a predetermined gap in the arrangement direction of heating elements 13a is arranged in at least one of an adhesive layer 16 and a double-sided tape 17. The diameter of the spacer particle 19 in the central part in the arrangement direction of the heating elements 13a is larger than the diameter of the spacer particle 19 at both ends in the arrangement direction of the heating elements 13a. The surface opposite to the radiator of the head base body is curved to project in the arrangement direction of the heating element 13a. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a recording head and a recording apparatus, and in particular, a recording head formed by adhering a head base having a heating element array in which a plurality of heating elements are arranged to a radiator with an adhesive layer and a double-sided tape, and a recording head; The present invention relates to a recording apparatus including a platen roller that presses a recording medium on a head base side of the recording head.

  As a printer such as a facsimile or a register, a thermal printer including a thermal head and a platen roller is used. As a thermal head mounted on such a thermal printer, a head substrate in which a plurality of heating elements are arranged on the surface of a head substrate, and mechanically connected to the head substrate and electrically connected to the plurality of heating elements. And a wiring member connected to each other.

  The platen roller has a function of pressing a recording medium such as thermal paper against the protective layer on the heating element side. In the thermal printer having such a configuration, the heating element is heated according to a desired image, and the recording medium is pressed against the protective layer on the heating element with a platen roller substantially uniformly, thereby generating heat generated by the heating element. Good transmission against. Desired printing on the recording medium is performed by repeating this process.

  FIG. 14 shows a conventional thermal head (a kind of recording head) X1. The thermal head X1 is configured by adhering a head substrate 50 to a radiator 80. FIG.

  The head base 50 includes a head substrate 51 having a rectangular main surface, a glaze layer 52, an electric resistance layer 53, an electrode wiring 54, and a protective layer 55.

  The electric resistance layer 53 has a heat generating element 53a that generates heat by supplying power. A portion of the electrical resistance layer 53 to which a voltage is applied from the electrode wiring 54, where the electrode wiring 54 is not formed, functions as the heating element 53 a.

  The glaze layer 52 has a flat base portion 52a and a protruding portion 52b, and the heat generating element 53a is located on the protruding portion 52b of the glaze layer 52, and has substantially the same spacing along the main scanning direction. They are arranged in a line by distance.

  Then, as shown in FIG. 14B, the head base 50 is bonded to the heat radiating body 80 with an adhesive layer 56 made of a heat radiating resin and a double-sided tape 57. That is, the lower surface of the head substrate 51 located immediately below the heat generating element 53a formed in the protruding portion 52b is an adhesive layer made of a heat-dissipating resin on the protruding surface between the two concave grooves 58 formed in the heat radiator 80. It is adhered at 56. The lower surface of the head substrate 51 and the heat radiating body 80 other than the portion located directly below the heating element 53a and the groove portion 58 are bonded with a double-sided tape 57. In FIG. 14B, only the protrusion 52 b of the glaze layer 52 is shown on the upper surface of the head substrate 51 for easy understanding.

  The lower surface of the head substrate 51 positioned immediately below the heat generating element 53a formed on the protruding portion 52b of the glaze layer 52 is bonded with an adhesive layer 56 made of a heat-dissipating resin, and a portion and a groove positioned directly below the heat generating element 53a. The reason why the double-sided tape 57 is joined to the heat radiating body 80 other than 58 is that the head base 50 is curved due to the difference in thermal expansion coefficient between the head substrate 51 made of ceramics and the heat radiating body 80. Although acting, the lateral flexibility of the double-sided tape 57 absorbs the difference in extension between the head base 50 and the heat radiating body 80 due to thermal expansion, and suppresses the curvature of the thermal head X1.

  Conventionally, since the adhesive layer 56 below the heat generating portion 53a is easily contracted by a strong pressing force from the platen roller, the heat generating element 53a group extending in the main scanning direction is formed by using the thermal head X1 for a long time. There are problems that the surface of the formed head substrate 51 is inclined or the interface peeling is partially caused in the adhesive layer 56 between the radiator 80 and the head substrate 51 to cause uneven density of the print. Therefore, the adhesive layer 56 contains spacer particles made of ceramics or the like having a particle size substantially the same as the thickness of the adhesive layer 56 (see Patent Document 1).

JP 2008-201013 A

  However, in the conventional thermal head X1, since the heat radiator 80 and the head substrate 51 are joined by the adhesive layer 56 via the spacer particles having the same particle diameter, the space between the heat radiator 80 and the head substrate 51 is reduced. The element 53a is constant at the center and both ends in the arrangement direction, whereby the upper surface of the head substrate 51, that is, the portion of the heating element 53a pressed by the platen roller is flat, and both ends are supported rotatably. Even if the support portions at both ends are pressed toward the recording head by the platen roller, the pressing force at the center in the arrangement direction of the heating elements 53a is lower than the pressing force at both ends in the arrangement direction of the heating elements 53a. Therefore, there is a possibility that print fading may occur in the central portion in the arrangement direction of the heating elements 53a.

  In particular, with a long recording head, the pressing force of the platen roller toward the head substrate 51 tends to be small at the center in the arrangement direction of the heat generating elements 53a, and there is a problem that print fading is likely to occur.

  An object of the present invention is to provide a recording head and a recording apparatus that can suppress fading.

  In the recording head of the present invention, a head base having a heat generating element array in which a plurality of heat generating elements are arranged on the upper surface is disposed on a heat radiating body, and a region immediately below the heat generating element array on the lower surface of the head base is disposed on the heat generating element. It is bonded to the heat radiating body through a strip-shaped adhesive layer extending in the arrangement direction of the elements, and the area other than the area directly below the heating element array on the lower surface of the head base is attached to the heat radiating body via a double-sided tape. A recording head formed by bonding, wherein at least one of the adhesive layer and the double-sided tape is a spacer particle that is in contact with the head substrate and the heat dissipating element at a predetermined interval in the arrangement direction of the heating elements. The particle size of the spacer particles at the center in the arrangement direction of the heating elements is made larger than the particle size of the spacer particles at both ends in the arrangement direction of the heating elements, And wherein said heat radiating member opposite to the surface on that allowed curved to be convex in the direction of arrangement of the heating elements.

  In such a recording head, the particle diameter of the spacer particles at the center in the arrangement direction of the heating elements is made larger than the particle diameter of the spacer particles at both ends in the arrangement direction of the heating elements, and the head is in contact with these spacer particles. Since the base is curved so that the surface on the side opposite to the radiator is convex in the arrangement direction of the heating elements, for example, the platen roller supported on both sides in the arrangement direction of the heating elements, the arrangement direction of the heating elements As with both sides, the recording medium can be sufficiently pressed toward the head substrate side, and the pressing force by the platen roller can be made substantially uniform in the arrangement direction of the heating elements. It is possible to suppress blurring of printing at the center of the direction.

  Further, by changing the arrangement position of the spacer particles having a large particle size, an arbitrary position of the head substrate can be protruded toward the platen roller, and further, the platen of the head substrate can be changed by changing the particle size of the spacer particles. The protrusion amount to the roller side can be controlled, and the pressing force by the platen roller can be controlled.

  In the recording head of the present invention, an aggregate composed of a plurality of spacer particles larger than the particle diameters of the spacer particles at both ends in the arrangement direction of the heating elements is present in the central portion in the arrangement direction of the heating elements. It is characterized by that.

  In such a recording head, since an aggregate composed of spacer particles is present in the central portion in the arrangement direction of the heating elements, a large amount of heat is radiated from the central portion in the arrangement direction of the heating elements through a plurality of spacer particles. Therefore, variation in heat dissipation can be suppressed between the central portion and both end portions in the arrangement direction of the heating elements.

  The recording apparatus of the present invention includes the above-described recording head and a platen roller that presses a recording medium against the head substrate side of the recording head, and the platen roller rotates at both ends in the arrangement direction of the heating elements. It is supported as possible. In such a recording apparatus, the pressing force by the platen roller can be made substantially uniform in the arrangement direction of the heat generating elements, and blurring of printing at the central portion in the arrangement direction of the heat generating elements can be suppressed.

  In the recording head according to the present invention, for example, a platen roller that supports both sides in the arrangement direction of the heat generating elements is sufficient at the central portion in the arrangement direction of the heating elements. The pressing force by the platen roller can be made substantially uniform in the arrangement direction of the heat generating elements, and blurring of printing at the central portion in the arrangement direction of the heat generating elements can be suppressed.

  Further, by changing the arrangement position of the spacer particles having a large particle size, an arbitrary position of the head substrate can be protruded toward the platen roller, and further, the platen of the head substrate can be changed by changing the particle size of the spacer particles. The protrusion amount to the roller side can be controlled, and the pressing force by the platen roller can be controlled.

(A) is a top view which shows schematic structure of the thermal head which is an example of embodiment of the recording head of this invention, (b) is a side view which shows schematic structure of the thermal head which is an example of embodiment of the recording head of this invention. FIG. (A) is the top view to which the principal part of the thermal head shown in FIG. 1 was expanded, (b) is sectional drawing along the IIb-IIb line | wire of (a). It is a disassembled perspective view of the wiring member shown in FIG. (A) is a perspective top view which shows the state by which the spacer particle | grains are arrange | positioned at the adhesive bond layer, (b) is sectional drawing along the IVb-IVb line | wire of (a), (c) is (a) ) Is a cross-sectional view taken along line IVc-IVc. (A) is a perspective plan view showing a state in which a plurality of large spacer particles are linearly arranged at predetermined intervals in the central portion in the arrangement direction of the heating elements, and (b) is a central portion in the arrangement direction of the heating elements. FIG. 6 is a perspective plan view showing a state in which a plurality of large spacer particles are randomly arranged. (A) is a perspective plan view showing a state in which three types of large, medium, and small spacer particles are arranged at predetermined intervals in the adhesive layer, and (b) is a cross section taken along line VIb-VIb in (a). FIG. (A) is a perspective top view which shows the state which has arrange | positioned the spacer particle | grains to the double-sided tape of the both sides of an adhesive bond layer, (b) is sectional drawing along the VIIb-VIIb line | wire of (a). (A) is a transparent top view which shows the state which has arrange | positioned spacer particle | grains to the adhesive bond layer and the double-sided tape of both sides of an adhesive bond layer, (b) is sectional drawing along the VIIIb-VIIIb line | wire of (a). is there. (A) is a perspective plan view showing a state in which three types of large, medium and small spacer particles are arranged at predetermined intervals on the adhesive layer and double-sided tape on both sides of the adhesive layer, and (b) is (a) ) Is a cross-sectional view taken along line IXb-IXb. (A) is a perspective plan view showing a state in which two rows of spacer particle rows composed of a plurality of spacer particles having substantially the same particle diameter are formed on a double-sided tape for fixing a wiring member; (b) It is sectional drawing along the Xb-Xb line | wire of (a). In (a), the head substrate is bonded to a heat radiator by an adhesive layer and a double-sided tape disposed on one side of the adhesive layer, and a plurality of spacer particles are arranged in a row on the adhesive layer and the double-sided tape. It is a perspective top view which shows the state currently carried out, (b) is sectional drawing along the XIb-XIb line | wire of (a). 1 is a diagram illustrating a schematic configuration of a thermal printer Y which is an example of an embodiment of a recording apparatus of the present invention. Fig. 7A shows the density measurement result of a print, and Fig. 9A is a graph showing the result of measuring the density at a constant interval in the scanning direction at a position 20 cm from the printing start position in the sub-scanning direction; It is explanatory drawing for demonstrating a measurement position. (A) is sectional drawing of the conventional thermal head, (b) is sectional drawing which shows the adhesion state of the head base | substrate to a heat radiator.

  FIG. 1A is a plan view showing a schematic configuration of a thermal head X as an example of an embodiment of a recording head according to the present invention, and FIG. 1B is a side view of the thermal head X.

  2A is an enlarged view of the main part of the thermal head X shown in FIG. 1, and FIG. 2B is a cross-sectional view taken along the line IIb-IIb shown in FIG. In FIG. 2A, the driving IC, the wiring member, the heat radiating body, and the protective layer are omitted from FIG. 2B, and the heat radiating body is omitted from FIG.

  The thermal head X includes a head substrate 10, a drive IC 20, a wiring member 30, and a heat radiator 40.

  The head base 10 includes a head substrate 11, a glaze layer 12, an electrical resistance layer 13, an electrode wiring 14, and a protective layer 15.

  The head substrate 11 has a function of supporting the glaze layer 12, the electrical resistance layer 13, the electrode wiring 14, the protective layer 15, and the drive IC 20. The head substrate 11 is configured in a rectangular shape extending in the arrow direction D1-D2 when viewed in the direction of the arrow D6, and the main surface is rectangular. Examples of the material for forming the head substrate 11 include insulating materials. For example, ceramics such as alumina ceramics and inorganic materials such as glass materials are preferably used.

  On the upper surface on the D5 direction side in the thickness direction D5-D6 of the head substrate 11, the electrical resistance layer 13 and the electrode wiring 14 can be easily patterned by photolithography, and the smoothness can be improved, so that the manufacture is easy. For this reason, the glaze layer 12 is provided throughout.

  The glaze layer 12 has a function of temporarily storing a part of heat generated in a heating element 13a described later of the electrical resistance layer 13. That is, the glaze layer 12 plays a role of improving the thermal response characteristics of the thermal head X by shortening the time required to raise the temperature of the heating element 13a. An example of a material for forming the glaze layer 12 is glass. The glaze layer 12 has a base portion 12a and a protruding portion 12b.

  The base portion 12a is provided in a substantially flat shape over the entire upper surface of the head substrate 11, and the thickness thereof is 20 to 250 μm. The protrusion 12b is a part that contributes to pressing the recording medium against the protective layer 15 located on the heating element 13a. The protrusion 12b protrudes in the direction D5 in the thickness direction D5-D6 from the base 12a. Further, the projecting portion 12b is formed in a strip shape extending in the main scanning direction D1-D2. The protrusion 12b has a substantially semi-elliptical cross section in the sub-scanning direction D3-D4 orthogonal to the main scanning direction D1-D2. In the present embodiment, the arrangement direction of the heating elements 13a is the main scanning direction of the thermal head X. The glaze layer 12 need not be formed on the entire top surface of the head substrate 11.

  The electrical resistance layer 13 is formed on the glaze layer 12. The electric resistance layer 13 has a thickness of 0.01 to 0.5 μm. In the present embodiment, a portion of the electrical resistance layer 13 to which a voltage is applied from the electrode wiring 14 where the electrode wiring 14 is not formed functions as the heating element 13 a, and the heating element 13 a is a protruding portion of the glaze layer 12. 12b is formed. Examples of the material for forming the electric resistance layer 13 include a TaN-based material, a TaSiO-based material, a TaSiNO-based material, a TiSiO-based material, a TiSiCO-based material, and an NbSiO-based material.

  The heat generating element 13 a generates heat when a voltage is applied from the electrode wiring 14. The heat generating element 13a is configured such that a heat generation temperature due to voltage application from the electrode wiring 14 is in a range of 200 to 550 ° C., for example.

  Further, the heating elements 13a are formed in a line at predetermined intervals in the direction of the arrows D1-D2, forming a heating element array. In the present invention, the number of heating element rows may be two or more.

  The electrode wiring 14 includes a first electrode wiring 141, a second electrode wiring 142, and a third electrode wiring 143.

  The end portion of the first electrode wiring 141 is connected to one end side of the plurality of heating elements 13a and a power source (not shown). One end of the first electrode wiring 141 is located on the arrow D3 direction side of the heating element 13a.

  The second electrode wiring 142 has one end connected to the other end of the heat generating element 13 a and the other end connected to the drive IC 20. One end of the second electrode wiring 142 is located on the arrow D4 direction side of the heating element 13a.

  The third electrode wiring 143 is formed away from the second electrode wiring 142, in other words, the third electrode wiring 143 is provided in the vicinity of the second electrode wiring 142. The third electrode wiring 143 is provided between the plurality of driving ICs 20 and the wiring member 30. The third electrode wiring 143 is connected to the driving IC 20 and the wiring member 30. In other words, the third electrode wiring 143 has a function of electrically connecting the driving IC 20 and the wiring member 30 and contributes to driving of the heating element 13a. Here, “contributes to driving of the heating element” means that a current flows along with driving or driving control of the heating element 13a. The third electrode wiring 143 has the driving IC 20 connected to one end thereof and the wiring member 30 connected to the other end thereof.

  As a material for forming the first electrode wiring 141, the second electrode wiring 142, and the third electrode wiring 143, for example, any one metal of aluminum, gold, silver, copper, or an alloy thereof can be given. The thickness is set to 0.7 to 1.2 μm.

The protective layer 15 has a function of protecting the heat generating element 13 a and the electrode wiring 14. The protective layer 15 covers the heat generating element 13a and a part of the electrode wiring 14. Examples of the material for forming the protective layer 15 include diamond-like carbon-based materials, SiC-based materials, SiN-based materials, SiCN-based materials, SiAlON-based materials, SiO ₂ -based materials, and TaO-based materials. It is formed. Here, “diamond-like carbon-based material” refers to a material in which the proportion of carbon atoms (C atoms) taking sp ³ hybrid orbits is in the range of 1 [atomic%] to less than 100 [atomic%]. Note that the protective layer 15 is omitted in FIG. 2A from the viewpoint of easy viewing.

  The drive IC 20 has a function of controlling power supply to the plurality of heating elements 13a. The drive IC 20 is connected to the second electrode wiring 142 and the third electrode wiring 143 through a conductive connection member 49 whose connection terminal is made of solder. With such a configuration, the heating element 13a can selectively generate heat in accordance with an electric signal input through the electrode wiring 14.

  FIG. 3 is an exploded perspective view illustrating a schematic configuration of the wiring member 30. The connection member of the wiring member 30 is connected to the first electrode wiring 141 and the third electrode wiring 143 through a conductive connection member 49 made of solder. The wiring member 30 has a function of transmitting an electric signal transmitted from the outside to the driving IC 20 and the electrode wiring 14. Examples of the electrical signal include power supplied to the heating element 13a and the driving IC 20, and image information for selectively controlling the power supply state of the heating element 13a. The wiring member 30 of this embodiment includes a wiring body 31, an external connection terminal 32, a support plate 33, and an adhesive layer 34.

The wiring body 31 includes a first wiring body 311, a second wiring body 312, and a wiring portion 313. As this wiring body 31, what has flexibility is employ | adopted, for example. Here, the flexibility means that the flexural modulus defined by JIS standard K7171 is, for example, 2.5 × 10 ^{3 to} 4.5 × 10 ³ N / mm ² .

The first wiring body 311 and the second wiring body 312 have a function of supporting the plurality of wiring portions 313 and ensuring their electrical insulation. The first wiring body 311 and the second wiring body 312 sandwich the wiring portion 313. Examples of a material for forming the first wiring body 311 and the second wiring body 312 include a flexible resin material including a polyimide resin, an epoxy resin, and an acrylic resin. In the present embodiment, the wiring body 31 is made of a polyimide resin, and its thermal expansion coefficient is about 1.1 × 10 ⁻⁵ K ⁻¹ . As thickness of the 1st wiring body 311 and the 2nd wiring body 312 in this embodiment, the range of 0.5-2.0 mm is mentioned, for example.

Examples of the material for forming the wiring portion 313 include any one kind of metal such as gold, silver, copper, and aluminum, or an alloy thereof. In the present embodiment, the wiring part 313 is made of copper, and its thermal expansion coefficient is about 1.7 × 10 ⁻⁵ K ⁻¹ .

  The external connection terminal 32 is a part to which an electric signal is input from the outside. The external connection terminal 32 is electrically connected to the drive IC 20 and the electrode wiring 14. Note that the external connection terminals 32 are omitted in FIG. 3 from the viewpoint of easy viewing.

The support plate 33 has a function of supporting the wiring body 31. Examples of a material for forming the support plate 33 include ceramics, resins, ceramics and resin composites. Examples of ceramics include alumina ceramics, aluminum nitride ceramics, silicon carbide ceramics, silicon nitride ceramics, glass ceramics, and mullite sintered bodies. Examples of resins include epoxy resins, polyimide resins, and acrylic resins. Examples thereof include thermosetting types such as resins, phenolic resins, and polyester resins, ultraviolet curable types, and chemical reaction curable types. In the present embodiment, the support plate 33 is made of glass fiber containing an epoxy resin, and has a thermal expansion coefficient of about 1.7 × 10 ⁻⁵ K ⁻¹ .

  The adhesive layer 34 has a function of bonding the wiring body 31 and the support plate 33. Examples of the thickness of the adhesive layer 34 include a range of 10 to 35 μm.

  The radiator 40 has a function of transmitting heat generated by driving the heat generating portion 13a to the outside. In the present embodiment, the radiator 40 functions as a support base material for the head base 10 and the wiring member 30. As a material for forming the radiator 40, for example, a metal material containing copper or aluminum can be used. Here, “a material having high thermal conductivity” means a material having higher thermal conductivity than the material constituting the head substrate 11. In particular, a radiator 40 made of a metal material, particularly aluminum, is desirable from the viewpoint of thermal conductivity.

  In the recording head, a head base 10 having a heat generating element array having a plurality of heat generating elements 13a arranged in a line on the upper surface is disposed on a heat radiating body 40. In other words, the surface of the head base 10 immediately below the heat generating element array is arranged in the direction in which the heat generating elements 13a are arranged as shown in FIGS. It is joined to the upper surface of the heat radiating body 40 through an adhesive layer 16 made of a heat-dissipating resin having a belt-like heat conductivity extending in the direction of the arrow D1-D2, and further, the lower surface of the head base 10 and the heating element 13a. A region other than the region directly below the surface, in other words, a portion located immediately below the heat generating element 13 a and the upper surface of the heat radiator 40 other than the groove 18 are bonded by the double-sided tape 17. The support plate 33 and the heat radiating body 40 are also bonded to each other with the double-sided tape 17. As the adhesive layer 16 made of a heat-dissipating resin, for example, a thermosetting type such as a silicone resin, an epoxy resin, a polyimide resin, an acrylic resin, a phenol resin, and a polyester resin containing a filler, a room temperature curing type Or it is a chemical reaction hardening type and a commercially available resin is mentioned.

  In the present invention, as shown in FIG. 4, spacer particles 19 that are in contact with the head base 10 and the radiator 40 are present in the double-sided tape 17. As shown in FIG. 4A, the spacer particles 19 are arranged in the center in the width direction of the belt-like adhesive layer 16 and in the direction in which the heating elements 13a are arranged (arrow D1-D2 direction, in other words, the adhesive layer 16). Are arranged in a row at a predetermined interval in the longitudinal direction). The surface on the adhesive layer side of the radiator 40 in the arrangement direction of the heating elements 13a is flat, and the thickness of the head substrate 11 in the arrangement direction of the heating elements 13a is constant. The spacer particles 19 may be formed in two or more rows.

  That is, the spacer particles 19 are arranged at both ends of the adhesive layer 16 in the arrangement direction of the heat generating elements 13a and at the center thereof, and the three spacer particles 19 are arranged linearly. Three or more spacer particles 19 may be arranged linearly. The particle size of the spacer large particles 19a at the center in the arrangement direction of the heat generating elements 13a is set larger than the particle size of the spacer small particles 19b at both ends in the arrangement direction of the heat generating elements 13a. The thickness of the adhesive layer 16 is the same as the particle size of the spacer particles 19 that contact the head substrate 10 and the heat radiating body 40, and the head substrate 10 that contacts the spacer particles 19 is as shown in FIG. In the arrangement direction of the heat generating elements 13a, the surface opposite to the heat radiating body 40 is curved so that it is convex, in other words, the platen roller 61 side is curved. In FIG. 4B, the platen roller 61 and the like are exaggerated.

  Thus, the platen roller 61 that supports both sides in the arrangement direction of the heating elements 13a can sufficiently press the recording medium toward the head substrate side, and the pressing force by the platen roller 61 is applied in the arrangement direction of the heating elements 13a. It can be made substantially uniform, and printing fading can be suppressed at the center in the arrangement direction of the heating elements 13a.

  Conventionally, when the head base 10 made of ceramic and the heat radiating body 40 made of metal are bonded by the thermosetting adhesive layer 16, the heat base 40 is opposite to the heat radiating body 40 of the head base 10 due to the difference in thermal expansion coefficient between them. Since the side was curved in a convex shape, the head substrate 10 could not be curved when using a room-temperature curable adhesive that does not use a heat-curable adhesive layer. Since the head substrate 10 is curved in a convex shape with a particle size of 19, the head substrate 10 can be curved in a convex shape even when bonding with a room-temperature curable adhesive.

  FIG. 4A shows a state in which the head substrate 10 of FIG. 4C is removed, and the spacer particles 19 are indicated by solid lines for easy understanding.

  The spacer particles 19 are ceramic particles, glass ceramic particles, glass particles, plastic particles, or the like. Ceramic particles are preferable from the viewpoint of maintaining flatness, and plastic particles are preferable from the viewpoint of scratch resistance. The spacer particles 19 are preferably spherical, but may be somewhat distorted. The particle diameter of the spacer particles 19 is substantially the same as the distance between the head base 10 and the heat radiator 40. There are at least three spacer particles 19. As the number of spacer particles increases, the stability of the head base 10 to the heat radiating body 40 increases.

  The particle size of the spacer large particles 19a and the spacer small particles 19b can be controlled so that the pressing force by the platen roller 61 is constant in the arrangement direction of the heating elements 13a. For example, when the pressing force at the center is smaller than both ends, the pressing force by the platen roller 61 can be controlled by further increasing the spacer large particles 19a. The difference in pressing force between the center part and the platen roller 61 at both ends tends to increase when the length of the heat generating elements 13a of the recording head is long. In general, the particle size of the spacer particles is 10 to 150 μm, and the particle size of the large spacer particles 19a is about 1.1 to 3 times that of the small spacer particles 19b.

  Even if there is some variation in the particle size of the spacer particles, the spacer particles may be deformed if they are soft spacer particles such as plastic particles, or may be slightly deformed if they are hard spacer particles such as ceramic particles. As a result, most of the spacer particles come into contact with the heat radiating body 40 and the head base 10.

  In order to improve the heat dissipation of the central part in the arrangement direction of the heat generating elements 13a, it can be coped with by making the thermal conductivity of the large spacer particles 19a higher than the thermal conductivity of the small spacer particles 19b. For example, the spacer small particles 19b can be formed of plastic particles, and the spacer large particles 19a can be formed by coating the surfaces of the plastic particles with metal. In addition, since plastic particles are deformed to some extent, vibration, displacement, and the like can be absorbed.

  In the present invention, as shown in FIG. 5, a spacer particle aggregate composed of a plurality of large-diameter spacer large particles 19a is arranged at the center of the adhesive layer 16 in the arrangement direction of the heating elements 13a, and both sides thereof are arranged. Small spacer small particles 19b may be arranged on the surface. FIG. 5 (a) is an example in which a plurality of large-diameter spacer large particles 19a are arranged in a straight line at a predetermined interval in the central portion in the arrangement direction of the heat generating elements 13a, and FIG. This is an example in which a plurality of large-diameter spacer large particles 19a are randomly arranged at the center in the arrangement direction of the elements 13a.

  In either case, as shown in FIG. 4B, in the arrangement direction of the heat generating elements 13a, the side opposite to the heat radiating body 40 of the head base 10 can be curved so as to be convex, The platen roller 61 supported on both sides in the arrangement direction of the heating elements 13a can sufficiently press the recording medium toward the head substrate side, and the pressing force by the platen roller 61 is substantially uniform in the arrangement direction of the heating elements 13a. In addition, it is possible to suppress fading of printing at the central portion in the arrangement direction of the heating elements 13a.

  FIG. 6 shows still another embodiment of the present invention. In this embodiment, the head base 10 and the radiator 40 are brought into contact with each other in the adhesive layer 16 at a predetermined interval in the arrangement direction of the heating elements 13a. While the spacer particles 19 are present, the particle size of the spacer particles 19 at the center in the arrangement direction of the heating elements 13a is set larger than the particle size of the spacer particles 19 at both ends in the arrangement direction of the heating elements 13a. Between the spacer large particles 19a at the center and the spacer small particles 19b at both ends, the middle spacer particle 19c having a particle size intermediate between the spacer large particles 19a at the center and the spacer small particles 19b at both ends. Is arranged.

  That is, three types of spacer particles 19a, 19b, and 19c are arranged between the head base 10 and the heat radiating body 40, and gradually become smaller from the central spacer large particles 19a toward both ends. The spacer middle particles 19c and the spacer small particles 19b are arranged. Even in such a recording head, the platen 10 can be curved so that the side opposite to the heat radiating body 40 of the head substrate 10 is convex in the arrangement direction of the heating elements 13a, and both sides in the arrangement direction of the heating elements 13a are supported. The roller 61 can sufficiently press the recording medium toward the head substrate side, and the pressing force by the platen roller 61 can be made substantially uniform in the arrangement direction of the heating elements 13a. And the shape of the head substrate 10 in the arrangement direction of the heat generating elements 13a can be stabilized. In this case, it is desirable to use plastic particles that can be deformed to some extent as the large, medium, and small spacer particles 19 because they are in contact with the head base 10 and the radiator 40.

  FIG. 7 shows still another embodiment of the present invention. In this embodiment, a spacer that contacts the head substrate 10 and the radiator 40 in the double-sided tape 17 at a predetermined interval in the arrangement direction of the heating elements 13a. While the particles 19 are present, the particle diameter of the spacer particles 19 at the center in the arrangement direction of the heating elements 13a is set larger than the particle diameter of the spacer particles 19 at both ends in the arrangement direction of the heating elements 13a.

  That is, as shown in FIG. 7A, the spacer particles 19 are provided in the double-sided tape 17 on both sides of the heating element array and at a predetermined interval in the arrangement direction of the heating elements 13a (arrow D1-D2 direction). Arranged in one row. That is, the spacer particles 19 are arranged at both ends in the arrangement direction of the heat generating elements 13a and at the center thereof, and the three spacer particles 19 are arranged linearly. FIG. 7A shows a state in which the head substrate 10 in FIG. 7B is removed. In order to facilitate understanding, the spacer particles 19 are indicated by solid lines.

  Also in this embodiment, the particle size of the spacer large particles 19a at the center in the arrangement direction of the heat generating elements 13a is larger than the particle size of the spacer small particles 19b at both ends in the arrangement direction of the heat generating elements 13a. In the direction, the plate body roller 61 can be curved so that the side opposite to the heat radiating body 40 of the head base 10 is convex, and the both sides in the arrangement direction of the heat generating elements 13a are supported. The pressing force by the platen roller 61 can be made substantially uniform in the arrangement direction of the heat generating elements 13a, and blurring of printing at the central portion in the arrangement direction of the heat generating elements 13a can be suppressed. Furthermore, in this case, since the head base 10 and the heat radiating body 40 located on both sides of the adhesive layer 16 are bonded and fixed by the double-sided tape 17 containing the spacer particles 19, the head base 10 located on both sides of the heating element array. Can be supported by the spacer particles 19, and the head substrate 10 can be fixed to the radiator 40 in a stable state.

  In the present invention, when the spacer particles 19 are pressed, the spacer particles 19 are embedded in the double-sided tape 17 and the spacer particles 19 need to contact the head base 10 and the heat radiating body 40. It is desirable to use a material having no base material such as a nonwoven fabric in the central portion in the thickness direction. For example, a double-sided tape without a base material using an acrylic adhesive can be used.

  The thickness of the double-sided tape 17 is approximately the same as the particle diameter of the spacer particles 19, and is substantially the same as the distance between the head base 10 and the radiator 40.

  In the case of this embodiment as well, as described in FIG. 5, a spacer particle aggregate made up of a plurality of small-diameter spacer small particles 19a may be provided at the center in the arrangement direction of the heating elements 13a. As described in FIG. 6, three kinds of spacer particles 19 may be used. In this case, the effects described in the description of FIGS. 5 and 6 can be obtained.

  FIG. 8 shows still another embodiment of the present invention. In this embodiment, the head base 10 and the heat radiating body are provided in the adhesive layer 16 and the double-sided tape 17 with a predetermined interval in the arrangement direction of the heating elements 13a. 40, and the particle size of the spacer particles 19 at the center in the arrangement direction of the heating elements 13a is larger than the particle size of the spacer particles 19 at both ends in the arrangement direction of the heating elements 13a. Is set. Thereby, the heat dissipation of the head base 10 at the central portion in the arrangement direction of the heat generating elements 13a can be improved, and the head base 10 can be fixed to the heat radiating body 40 in a stable state.

  In the case of this embodiment as well, as described with reference to FIG. 5, a spacer particle aggregate composed of a plurality of large spacer particles 19a may be provided at the center in the arrangement direction of the heating elements 13a. As described, three types of spacer particles 19 may be used. In this case, the effects described in the description of FIGS. 5 and 6 can be obtained.

  FIG. 9 shows a configuration in which three types of spacer particles 19 a, 19 b, 19 c are arranged in the adhesive layer 16 and the double-sided tape 17, and the head substrate 10 is joined to the radiator 40.

  FIG. 10 shows still another embodiment of the present invention. In this embodiment, not only the double-sided tape 17 to which the head substrate 40 is bonded, but also the double-sided tape 17 for fixing the wiring member 30 is provided with a plurality of spacers. A spacer particle array made of particles 19 is formed. In such a thermal head, the support plate 33 is supported by two rows of spacer particle rows in which spacer particles 19 of the same particle size are arranged at a predetermined interval, and the support plate 33 is bonded to the support plate 33. 33 can be stably bonded, the inclination of the wiring member 30 can be suppressed, and the bonding strength between the head base 10 and the wiring member 30 can be improved.

  FIG. 11 shows still another embodiment of the present invention. In this embodiment, the head substrate 10 includes a heat radiating body 40 including an adhesive layer 16 and a double-sided tape 17 disposed on one side of the adhesive layer 16. In the adhesive layer 16 and the double-sided tape 17, a plurality of spacer particles 19 are arranged in a line. Even such a thermal head can be curved so that the side opposite to the heat radiating body 40 of the head base 10 is convex in the arrangement direction of the heating elements 13a, and both sides in the arrangement direction of the heating elements 13a are supported. The platen roller 61 can sufficiently press the recording medium toward the head substrate, and the pressing force by the platen roller 61 can be made substantially uniform in the arrangement direction of the heating elements 13a. It is possible to suppress faint printing.

  In addition, when the head substrate 11 of the head base 10 is formed thin (1 mm or less) from the viewpoint of thermal conductivity, the head substrate 11 is easily deformed, so that the present invention can be preferably used. Moreover, since the head substrate 11 is easily deformed even when the length of the head substrate 11 is 100 mm or more, that is, when the heating element array is long, the present invention can be suitably used. Furthermore, since the head substrate 11 is easily deformed even when the width of the head substrate 11 (the length in the direction of the arrows D3-D4) is 10 mm or less, the present invention can be preferably used.

In particular, in the recording head for images and medical use, since the head substrate 11 tends to be long, the present invention can be suitably used.
<Method for manufacturing recording head>
Next, the manufacturing method of the recording head of the present invention will be described by taking the above-described thermal head X as an example of the recording head as an example.

  First, an element body preparation step is performed. Specifically, a mother substrate having a plurality of head substrate regions is prepared. Next, a glaze layer forming step is performed. Specifically, the glaze layer 12 is formed on the entire upper surface of the mother substrate. Examples of the forming method include known methods such as a printing method and a baking method.

  Next, a resistor film is formed on the entire upper surface of the glaze layer 12 formed on each head substrate region. Examples of the film forming method include conventionally known methods including sputtering technology and vapor deposition technology. Next, a conductive film is formed on the entire upper surface of the resistor film. Examples of the method for forming the conductive film include conventionally known methods including sputtering technology and vapor deposition technology.

  Next, the conductive film and the resistor film are etched into a predetermined pattern to form the electrode wiring 14, and then etched again to remove a part of the electrode wiring 14 and expose a part of the resistor film, thereby heating element 13a. To function as. At this time, an element row composed of a plurality of heating elements 13a is arranged along arrow directions D1 and D2. As this etching method, for example, a conventionally known method including a combination of a photoresist technique and a wet etching technique can be cited.

  Next, a protective layer 15 forming step is performed. Specifically, the protective layer 15 is formed so as to cover the heat generating portion 13a and a part of the electrode wiring 14 by sputtering.

  Next, a mother substrate dividing step is performed. Specifically, the mother substrate is divided into head substrate regions to obtain a plurality of head substrates 11.

  Next, a wiring member is prepared. Specifically, first, a wiring body 31 including a first wiring body 311, a second wiring body 312, and a wiring portion 313 is prepared. Next, an adhesive 34 is applied to the upper surface of the support plate 33, and the wiring body 31 is joined to the support plate 33.

  Next, a wiring member bonding step is performed. Specifically, first, a solder paste that becomes the conductive connection member 49 is applied on the first electrode wiring 141 and the third electrode wiring 143 of the head substrate 10. Next, the first electrode wiring 141, the third electrode wiring 143, and the connection terminal of the wiring member 30 are opposed to each other through a solder paste and heated, and the first electrode wiring 141, the third electrode wiring 143, and the wiring member 30 are connected. The connection terminal is fixed with heat-melted solder.

  Next, a driving IC mounting process is performed. Specifically, first, a solder paste that becomes the conductive connection member 49 is applied to the second electrode wiring 142 and the third electrode wiring 143, and the second electrode wiring 142 and the third electrode wiring 143 are driven via the solder paste. The connection terminals of the IC 20 are made to face each other, and then the solder paste is thermally melted to connect the second electrode wiring 142 and the third electrode wiring 143 and the connection terminals of the driving IC 20.

  Next, the head base 10 and the wiring member 30 are joined on the heat radiating body 40. This will be specifically described. A heat-dissipating adhesive is applied to the projecting surface between the concave grooves 18 of the heat radiating body 40 in which the concave grooves 18 are formed in the directions indicated by the arrows D1-D2.

  On the other hand, the double-sided tape 17 is affixed to the upper surface of the heat radiating body 40 other than the protruding surface between the concave grooves 18. Thereafter, the spacer particles 19 are arranged in a line at a predetermined interval on the upper surface of the double-sided tape 17 by a dispenser or the like. The process of applying the heat-dissipating adhesive and the process of applying the double-sided tape 17 may be reversed.

  Then, the head base 10 is disposed on the upper surface of the heat radiating body 40 to which the adhesive is applied and the double-sided tape 17 is attached, and the head base 10 is pressed toward the heat radiating body 40 to thereby attach the spacer particles 19 to the adhesive. The recording medium is embedded in the double-sided tape 17, the lower surface of the head base 10 is bonded to the double-sided tape 17, and the head base 10 is bonded with the adhesive layer 16 in which the adhesive is cured. Can be produced.

  Note that a double-sided tape in which spacer particles are embedded at a predetermined interval may be attached to the upper surface of the radiator 40 in advance.

As described above, the thermal head X is formed.
<Recording device>
FIG. 12 is a diagram showing a schematic configuration of a thermal printer Y which is an example of an embodiment of a recording apparatus of the present invention.

  The thermal printer Y includes a thermal head X, a transport mechanism 59, and a control mechanism 69.

  The transport mechanism 59 has a function of bringing the recording medium P into contact with the heating element 13a of the thermal head X while transporting the recording medium P in the direction of the arrow D3. The transport mechanism 59 includes a platen roller 61 and transport rollers 62, 63, 64, and 65.

  The platen roller 61 has a function of pressing the recording medium P toward the heating element 13a. The platen roller 61 is supported at both ends so as to be rotatable while in contact with the protective layer 15 located on the heating element 13a. The platen roller 61 has a configuration in which an outer surface of a columnar base is covered with an elastic member. This base is made of, for example, a metal such as stainless steel, and this elastic member is made of, for example, butadiene rubber having a thickness of 3 to 15 mm.

  The transport rollers 62, 63, 64 and 65 have a function of transporting the recording medium P. That is, the transport rollers 62, 63, 64, 65 supply the recording medium P between the heating element 13 a of the thermal head X and the platen roller 61, and between the heating element 13 a of the thermal head X and the platen roller 61. It plays a role of pulling out the recording medium P from the recording medium. These transport rollers 62, 63, 64, 65 may be formed by, for example, a metal columnar member. For example, like the platen roller 61, the outer surface of the columnar substrate is covered with an elastic member. There may be.

  The control mechanism 69 has a function of supplying image information to the drive IC 20. That is, the control mechanism 69 plays a role of supplying image information for selectively driving the heat generating portion 13 a to the drive IC 20 via the external connection terminal 32.

  The thermal printer Y includes a thermal head X and a transport mechanism 59 that transports the recording medium P. Therefore, the thermal printer Y can enjoy the effects of the thermal head X. Therefore, the thermal printer Y can suppress blurring of printing and improve image quality.

  While specific embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the invention.

  A head base and a radiator were prepared. As the head substrate, a head substrate made of an alumina substrate having a width of 9 mm, a length of 168 mm, and a thickness of 1 mm was used, and a heating element array was formed in the length direction of the head substrate. The radiator is made of Al and has a width of 20 mm, a length of 170 mm, and a thickness of 4 mm, and two grooves are formed in a portion corresponding to the heating element array.

  A 50 μm-thick double-sided tape (manufactured by 3M 468: a type without a base material using an acrylic adhesive) was attached to the upper surface of the radiator other than the protruding surface between the concave grooves.

  A dispenser was used on the projecting surfaces between the concave grooves of the radiator, and a room temperature curing type heat radiating resin (manufactured by Toray: SE4420) was applied to a thickness of 50 μm.

  Spacer particles (manufactured by Sekisui Chemical Co., Ltd .: Micropearl: Material: Plastic) were placed on the heat-dissipating resin. As shown in FIG. 4, large spacer particles having a particle size of 100 μm are arranged at the center in the arrangement direction of the heating elements, and small spacer particles having a particle size of 50 μm are arranged at both ends.

  The head substrate is placed on the top surface of the heat-dissipating resin on which spacer particles are arranged, and the heat-dissipating resin is cured at room temperature with the flat area between the heating element array and the IC pressed against the heat-dissipating member side with a press. A thermal head A of the present invention was produced.

  Further, a comparative thermal head B was produced in the same manner as described above without including spacer particles in the adhesive layer made of a heat-dissipating resin.

  The flatness of the produced thermal head was measured by bringing a contact-type measuring head into contact with the surface of the protective layer 15 immediately above the heating element 13a. From this line segment, the line segment connecting both ends of the head substrate 10 was used as a reference. With a protruding height of

  In the thermal head of the present invention, the central portion of the head base in the arrangement direction of the heating elements protrudes about 50 μm from both sides. Thus, it can be seen that the head substrate can be formed in a convex shape without processing the heat sink even when a room temperature curable heat radiating resin is used. On the other hand, in the thermal head of the comparative example, the head substrate was not curved.

  The created thermal head was mounted on an actual machine (high-speed color printer) and a printing test was conducted. Synthetic paper was used as the recording medium.

  The print start position was set to 0, the print density was measured at a fixed interval in the main scan direction at a position 20 cm from the print start position in the sub-scan direction, and the density stability was observed. The density measurement of the prints was performed with Macbeth RD914 type based on the ISO 5 series of international standards. The results are shown in FIG. The thermal head A of the present invention in which spacer particles are arranged on a heat-dissipating resin is indicated by a broken line, and the thermal head B of a comparative example is indicated by a one-dot chain line.

  From FIG. 13A, it can be seen that the thermal head of the present invention does not show a large change in the density in the main scanning direction. It can be seen that the head substrate can be formed in a convex shape, the pressing force with the platen roller can be uniform, and a stable print without density unevenness can be obtained. In addition, by using a room temperature curable heat radiating resin, the heat radiating plate is not heated and the heat radiating plate is not warped, so that the spacer can be held in a flat state.

  On the other hand, since the thermal head of the comparative example does not contain spacer particles in the heat-dissipating resin, it is understood that the pressing force by the platen roller is low in the central portion, the density in the central portion is reduced, and density unevenness occurs. .

  Furthermore, this inventor produced the thermal head C which has arrange | positioned the spacer particle | grains similar to the above to double-sided tape, without arrange | positioning spacer particle | grains in heat dissipation resin. That is, a large spacer particle having a particle size of 100 μm is arranged at the center in the arrangement direction of the heating elements, and a small spacer particle having a particle size of 50 μm is arranged on both sides of the heat-dissipating resin as shown in FIG. A thermal head C of the present invention was produced. Also for this, the stability of the concentration was observed and added to FIG. 13A by a solid line.

  From FIG. 13A, even when spacer particles are arranged on the double-sided tape, the head substrate can be formed in a convex shape, the pressing force with the platen roller can be uniform, and stable without unevenness in density. It can be seen that the printed image is obtained.

X thermal head Y thermal printer 10 head substrate 11 head substrate 12 glaze layer 13 electrical resistance layer 13a heating element 14 electrode wiring 141 first electrode wiring 142 second electrode wiring 143 third electrode wiring 15 protective layer 16 adhesive layer 17 double-sided tape 18 Concave groove 19 Spacer particle 19a Spacer large particle 19b Spacer small particle 19c Spacer middle particle 20 Driving IC
30 Wiring member 40 Heat radiating body 59 Conveying mechanism 61 Platen rollers 62, 63, 64, 65 Conveying roller 69 Control mechanism P Recording medium

Claims (3)

  A head base having a heat generating element array in which a plurality of heat generating elements are arranged on the upper surface is disposed on a heat radiating body, and a region immediately below the heat generating element array on the lower surface of the head base extends in the arrangement direction of the heat generating elements. A recording head formed by adhering to the heat radiating body via an adhesive layer and adhering a region other than the region directly below the heating element array on the lower surface of the head base to the heat radiating member via a double-sided tape. Spacer particles that contact the head base and the heat dissipating element are arranged in at least one of the adhesive layer and the double-sided tape at a predetermined interval in the arrangement direction of the heat generating elements, and the heat generating elements The particle diameter of the spacer particles at the center in the arrangement direction of the heater element is larger than the particle diameter of the spacer particles at both ends in the arrangement direction of the heating elements, and the side opposite to the radiator of the head substrate Recording head, characterized in that the surface was allowed curved to be convex in the direction of arrangement of the heating elements.   The central portion in the arrangement direction of the heating elements includes an aggregate of a plurality of spacer particles larger than the particle diameter of the spacer particles at both ends in the arrangement direction of the heating elements. Item 2. The recording head according to Item 1.   3. The recording head according to claim 1 and a platen roller that presses a recording medium against a head substrate side of the recording head, and the platen roller is rotatable at both ends in the arrangement direction of the heating elements. And a recording apparatus.

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