JP5925457B2 - Thermal print head and thermal printer - Google Patents

Description

  The present invention relates to a thermal print head and a thermal printer.

  A thermal print head is an output device that generates heat from a plurality of heating elements arranged in a heat generating portion and forms images such as characters and figures on a medium such as thermal recording paper by the heat. This thermal print head is widely used in recording devices such as barcode printers, digital plate-making machines, video printers, imagers, and seal printers.

  A general thermal print head includes a heat radiating plate, a heat generating plate attached to the heat radiating plate, and a circuit board attached to the heat radiating plate on the same side as the heat generating plate. A plurality of heat generating resistors are linearly arranged at predetermined intervals in a heat generating region extending in a band shape on the surface opposite to the surface of the heat generating plate facing the heat radiating plate. The circuit board is mounted with electrical components such as a drive IC that is a part of a drive circuit that drives the heating resistor.

  A printer using such a thermal print head generally includes a platen roller formed in a cylindrical shape with a material having a predetermined elasticity. The platen roller has an axis parallel to the main scanning direction in which the heating resistors are arranged, and is arranged so that its side surface is in contact with the heat generation area on the support substrate, and is provided to be rotatable about the axis. Due to the rotation of the platen roller, the medium inserted between the platen roller and the heat generating area moves in the sub-scanning direction perpendicular to the main scanning direction. While pressing the medium against the heat generation area by the platen roller, the medium is moved in the sub-scanning direction, and the heat generation pattern of the heating resistor is changed with the movement of the medium, thereby forming a desired image on the medium.

JP 2001-389939 A

  Some thermal print heads are provided with a common electrode on the downstream side in the sub-scanning direction with respect to the heating resistor, and others are connected by a folded electrode provided on the downstream side in the sub-scanning direction with adjacent heating resistors. At the time of printing, a current flows from the connected driving IC to the individual electrodes connected to the heating resistor constituting the predetermined pixel, and the heating resistor generates heat accordingly, and is printed on the medium. However, in any case, a predetermined drive element is required to obtain a predetermined resolution.

  Therefore, an object of the present invention is to enable printing with two types of resolutions with a thermal print head.

In order to solve the above-described problems, the present invention provides a thermal printhead, wherein an insulating substrate having a main surface extending in a main scanning direction is arranged in a sub-scanning direction perpendicular to the main scanning direction and connected by a first wiring . a first resistor and a second resistor, adjacent to the position in the main scanning direction in the second resistor antibody, and the sub-scanning direction position and the arrangement position of the second resistor is provided in the same position the first A plurality of third resistors that are connected to two resistors and connected in series on the same side in the sub-scanning direction with a second wiring and are arranged in the main scanning direction, and are formed by the first resistors. A first heat generating region and a resistor group having a second heat generating region formed by the second resistor and the third resistor, and a common connection to each of the first resistors of the plurality of resistor groups. A first common electrode and a plurality of the resistors; A second common electrode connected to the third resistor remote from each of said second resistor, towards the first close the said second resistor for each resistor group to the second resistor And an individual electrode connected to the three resistors.

According to the present invention, in the thermal printer, an insulating substrate having a main surface extending in the main scanning direction, a first resistor and a second resistor arranged in a sub-scanning direction perpendicular to the main scanning direction and connected by a first wiring . a resistor, at a location to adjacent in the main scanning direction in the second resistor antibody, and position and the sub-scanning direction position of the second resistor connected to the second resistor provided at the same position the A plurality of first resistors that are arranged in the main scanning direction and are formed by the first resistors; and two third resistors connected in series by the second wiring on the same side in the sub-scanning direction. A resistor group having a second heat generating region formed by the second resistor and the third resistor, a first common electrode commonly connected to each of the first resistors of the plurality of resistor groups;
A second common electrode commonly connected to the third resistor farther from each second resistor of the plurality of resistor groups; the second resistor and the second resistor for each resistor group ; A thermal printhead having an individual electrode connected to the third resistor closer to the plate, a platen roller that rotates about a rotation axis parallel to the longitudinal direction of the insulating substrate, and the attitude of the thermal printhead And a posture adjusting mechanism that presses either the first heat generation area or the second heat generation area against the platen roller.

  According to the present invention, two types of resolution printing can be performed with one thermal print head.

It is a top view of the wiring pattern of the heat generating body board in one Embodiment of the thermal print head which concerns on this invention. It is a circuit diagram of a part of an embodiment of a thermal print head according to the present invention. 1 is a plan view of an embodiment of a thermal print head according to the present invention. It is sectional drawing of the heat generating body board in one Embodiment of the thermal print head concerning this invention. 1 is a cross-sectional view of a thermal printer using an embodiment of a thermal print head according to the present invention. It is sectional drawing which shows the attitude | position in the case of printing using the 2nd heat_generation | fever area | region of the thermal printer using one embodiment of the thermal print head concerning this invention.

  An embodiment of a thermal print head according to the present invention will be described with reference to the drawings. This embodiment is merely an example, and the present invention is not limited to this.

  FIG. 3 is a plan view of an embodiment of a thermal print head according to the present invention. FIG. 4 is a cross-sectional view of the heating plate in the present embodiment.

  The thermal print head 10 according to the present embodiment includes a heat radiating plate 20, a heat generating plate 30, and a circuit board 21. The heat sink 20 is a rectangular plate made of aluminum, for example. The heat generating plate 30 and the circuit board 21 are placed on the same surface of the heat radiating plate 20.

The heating element plate 30 includes a ceramic substrate 33, a glaze layer 34, a resistor layer 35, an electrode layer 36, and a protective film layer 37. The ceramic substrate 33 is, for example, a rectangular plate of alumina (Al ₂ O ₃ ). The glaze layer 34 is fixed to the surface of the ceramic substrate 33. The ceramic substrate 33 and the glaze layer 34 constitute an insulating substrate whose main surface is the surface of the glaze layer 34. The longitudinal direction of the insulating substrate is called a main scanning direction, and the direction perpendicular to the main scanning direction and along the main surface is called a sub-scanning direction.

  A part of the glaze layer 34 is formed with a ridge 38 protruding in the normal direction of the surface of the ceramic substrate 33 on which the glaze 34 is formed. The protrusions 38 extend in the longitudinal direction (main scanning direction) of the ceramic substrate 33. The resistor layer 35 and the electrode layer 36 are laminated on the main surface of the insulating substrate including the ceramic substrate 33 and the glaze layer 34.

  The resistor layer 35 and the electrode layer 36 are formed in a predetermined plane pattern. A gap is formed in a part of the electrode layer 36, and these gap portions become heat generation regions 31 and 32 where the resistor layer 35 generates heat. The heat generating regions 31 and 32 are provided on the surface of the ridge 38 in two straight lines extending in the main scanning direction and parallel to each other. Of these heat generating regions 31 and 32, the one closer to the edge of the insulating substrate is referred to as a first heat generating region 31, and the farther one is referred to as a second heat generating region 32. The second heat generating region 32 is provided at the top of the ridge 38, for example. The first heat generating region 31 is provided, for example, on a slope portion of the ridge 38.

  The protective film layer 37 covers the glaze layer 34, the resistor layer 35, and the electrode layer 36. A part of the electrode layer 36 is not covered with the protective film layer 37, and the part serves as a connection pad 39 with the circuit board 21.

  A switch 22 and a plurality of drive elements 23 are mounted on the circuit board 21. A bonding wire 24 is bridged between the switch 22 and the driving element 23 and the heating element plate 30. The bonding wire 24, the switch 22, and the drive element 23 are sealed with a sealing resin 25.

  FIG. 1 is a plan view of a wiring pattern of a heating element plate in the present embodiment. FIG. 2 is a circuit diagram of a part of the thermal print head in the present embodiment.

  The heating element plate 20 is provided with a first resistor 41, a second resistor 42, and a third resistor 43. The first resistor 41, the second resistor 42, and the third resistor 43 are provided in the resistor layer 35.

  One first resistor 41, one second resistor 42, and two third resistors 43 form one resistor group. This resistor group is arranged in the main scanning direction on the main surface of the insulating substrate.

  The first resistors 41 are linearly arranged on the surface of the ridges 38 at regular intervals in the direction in which the ridges 38 extend. The plurality of arranged first resistors 41 form a first heat generating region 31.

  The second resistors 42 are linearly arranged on the surface of the protrusion 38 at different positions in the short side direction of the first resistor 41 and the ceramic substrate 33. The number of second resistors 42 is the same as the number of first resistors 41. The second resistors 42 are arranged at the same pitch as the first resistors 41.

  The third resistors 43 are linearly arranged at intervals on the surface of the protrusion 38 at different positions in the short side direction of the first resistor 41 and the ceramic substrate 33. Two third resistors 43 are arranged between two adjacent second resistors 42. The resistor rows made up of the second resistor 42 and the third resistor 43 are arranged at an equal pitch.

  Further, the heating element plate 30 is provided with a first wiring 51, a second wiring 52, a first common electrode 61, a second common electrode 62, and an individual electrode 71. The first wiring 51, the second wiring 52, the first electrode 61, the second electrode 62, and the individual electrode 71 are provided in the electrode layer 36.

  The first wiring 51 connects the first resistor 41 and the second resistor 42. The first wiring 51 extends in the short side direction (sub-scanning direction) of the ceramic substrate 41.

  The second wiring 52 connects two adjacent third resistors 43 disposed between two adjacent second resistors 42. The second wiring 52 is arranged closer to the first resistor 41 than the third resistor 43 in the short direction (sub-scanning direction) of the ceramic substrate 33. The second resistor 42 extends from the end of one third resistor 43 in the short direction (sub-scanning direction) of the ceramic substrate 33 and then returns to the end of the adjacent third resistor 43. .

  The first common electrode 61 is connected to the opposite side of the first resistor 41 from the first wiring 51. The first common electrode extends in the longitudinal direction (main scanning direction) of the ceramic substrate 33 on the opposite side of the first resistor 41 from the first wiring 51.

  The second common electrode 62 is connected to the opposite side to the second wiring 52 of the third resistor 43 closer to the second resistor 42 out of the two connected by the second wiring 52. The second common electrode 62 extends in the longitudinal direction (main scanning direction) of the ceramic substrate 33 on the opposite side of the third resistor 43 from the second wiring 52.

  The individual electrode 71 is the third resistor 43 on the opposite side of the second resistor 42 from the first wire 51 and on the other of the two connected by the second wire 52 and not connected to the second common electrode 62. The second wiring 52 is connected to the opposite side. The individual electrode 71 extends in the short direction (sub-scanning direction) of the ceramic substrate 41.

  A connection pad 39 is formed at the end of the individual electrode 71 opposite to the second resistor 42 and the third resistor 43. The connection pad 39 is provided closer to the second resistor 42 and the third resistor 43 than the second common electrode 62.

  Connection pads 39 are formed at the ends of the first common electrode 61 and the second common electrode 62. The connection pads 39 at the ends of the first common electrode 61 and the second common electrode 62 are provided, for example, at the same position in the short side direction (sub-scanning direction) of the connection pad 39 at the end of the individual electrode 71 and the ceramic substrate 33. ing.

  The individual electrode 71 is connected to the drive element 23 through the bonding wire 24 connected to the connection pad 39 at the end thereof. The first common electrode 61 and the second common electrode 62 are connected to the switch 22 through bonding wires 24 connected to the connection pads 39 at the respective ends. A power source 26 is connected to the switch 22. The switch 22 connects the power supply 26 to the first common electrode 61 or the second common electrode 62. The switch 22 may have a state in which the power supply 26 is not connected to either the first common electrode 61 or the second common electrode 62.

  The first resistor 41, the second resistor 42, and the third resistor 43 all have the same width and the same length. Therefore, all the resistance values are the same. The lengths of the first resistor 41, the second resistor 42, and the third resistor 43 are all 200 μm, for example.

  Further, since the voltage of the power source 26 is applied to the first resistor 41 and the second resistor 42 connected in series, or the two third resistors 43 connected in series, the first resistor 41 and Each of the second resistor 42 and the third resistor 43 generates heat with the same heat generation amount per unit time.

  FIG. 5 is a cross-sectional view of a thermal printer using the thermal print head of the present embodiment.

  The thermal printer includes a thermal print head 10, a pedestal 81, a pusher 83, two stoppers 84 and 85, a spring 88, a fixing portion 87, and a platen roller 11. The pedestal 81 is provided so as to be rotatable about the shaft 86. The thermal print head 10 is fixed to the pedestal 81 with, for example, screws that pass through the pedestal 81 and are screwed into the heat dissipation plate 20 of the thermal print head 10.

  The spring 88 urges the pedestal 81 in a direction that rotates about the shaft 86. The shaft 86 is preferably disposed at the center of curvature of the protrusion 38 formed in the glaze layer 34.

  The pushing tool 83 rotates the pedestal 81 about the shaft 86 by pushing the pedestal 81. The two stoppers 84 and 85 are provided so as to stop the pedestal 81 biased by the spring 88 at a predetermined position. The stoppers 84 and 85 have, for example, a bar extending upward from the fixed part 87 and a protrusion protruding in the direction of the base 81 from the end of the bar. The fixing unit 87 is fixed to a housing (not shown) of the printer, for example.

  The change in the posture of the thermal print head 10 between the state where the pedestal 81 is engaged with one stopper 84 and the state where the pedestal 81 is engaged with the other stopper 85 is that the curvature center of the ridge 38 and the first heat generation region 31 are changed. And the angle formed by the second heat generating region 32 is made equal. For example, the first heat generation area 31 and the second heat generation area 32 each have an angle formed by a straight line passing through the center of curvature of the ridge 38, and the state in which the base 81 is engaged with one stopper 84 and the other. The posture of the thermal print head 10 is changed by 7.5 degrees when the pedestal 81 is engaged with the stopper 85.

  The platen roller 11 is a cylinder having elasticity that rotates around the rotation axis 12 parallel to the first heat generation region 31 and the second heat generation region 32. The side surface of the platen roller 11 is pressed against the first heat generation area 31 or the second heat generation area 32 with the print medium 13 interposed therebetween.

  In printing using the thermal print head 10, there are a case where the first heat generation region 31 is used and a case where the second heat generation region 32 is used.

  FIG. 6 is a cross-sectional view showing a posture when printing is performed using the second heat generating area of the thermal printer using the thermal print head of the present embodiment.

  When printing using the second heat generating area 32, the pedestal 81 is pushed toward the fixing portion 87 by the pusher 83 and is engaged with the stopper 85. As a result, the pedestal 81 rotates about the shaft 86, and the second heat generation region 32 is pressed against the side surface of the platen roller 11.

  In this state, the switch 22 is switched to connect the power source 26 and the first common electrode 61. Thereafter, a current flows through the first resistor 41 by turning on the terminal of the drive element 23 connected to the first resistor 41 at the position to be printed. As a result, the first resistor 41 generates heat, and one line of a desired image is printed. Further, the printing medium 13 is conveyed in the sub-scanning direction by one line using the platen roller 11 or other conveying means, and one line of a desired image is printed again. By repeating such an operation, a desired image is printed.

  When printing using the first heat generating area 31, the pusher 83 is pulled back and the stopper 85 is moved to a position where it does not engage with the pedestal 81 by some means, so that the pedestal 81 is moved to another stopper by the force of the spring 88. Rotate to a position where it engages with 84. As a result, the first heat generating region 31 is pressed against the side surface of the platen roller 11.

  In this state, the switch 22 is switched to connect the power source 26 and the first common electrode 61. Thereafter, the terminal of the drive element 23 connected to the second resistor 42 at the position to be printed is turned ON, whereby a current flows through the second resistor 42. As a result, the second resistor 42 generates heat and is printed at a desired position. Thereafter, the switch 22 is switched to connect the power source 26 and the second common electrode 62 without conveying the printing medium 13. After that, the terminal of the drive element 23 connected to the third resistor 43 at the position to be printed is turned ON, so that a current flows through the third resistor 43. As a result, the third resistor 43 generates heat and is printed at a desired position.

  In this way, the switch 22 is switched to the first common electrode 61 side and the second common electrode 62 side without moving the printing medium 13, and one line of a desired image is printed in two stages. Thereafter, the printing medium 13 is conveyed by one line in the sub-scanning direction, and one line of a desired image is printed again. By repeating such an operation, a desired image is printed.

  In the second heat generating region 32, the number of heat generating resistors that generate heat independently is larger than that in the first heat generating region 31. That is, the resolution when printing in the second heat generation area 32 is higher than the resolution when printing in the first heat generation area 31.

  As described above, when the thermal print head 10 according to the present embodiment is used, it is possible to perform printing with different resolutions using a single thermal print head. At this time, since the switch 22 is used, it is only necessary to have a drive element 23 necessary for printing a low resolution. As a result, the thermal print head 10 can be downsized or made inexpensive.

  Furthermore, since the resistance values of the first resistor 41, the second resistor 42, and the third resistor 43 are the same, the amount of heat generated can be made the same even if one type of power source is used. That is, it is not necessary to use two types of power supplies to obtain two types of resolution.

  Further, in the present embodiment, the second resistor 42 and the third resistor 43 are arranged downstream of the first resistor 41 in the transport direction of the print medium 13, but may be arranged upstream. That is, the positions of the first heat generation area 31 and the second heat generation area 32 in the sub-scanning direction may be switched.

  In the present embodiment, the first resistor 41, the second resistor 42, and the third resistor 43 have the same width and length and the same resistance value, but may be the same in other methods. it can. For example, the width of the third resistor 43 may be smaller than that of the first resistor 41 and the second resistor 42, and the length may be shorter than that of the first resistor 41 and the second resistor 42. Thereby, since the pitch of the arrangement | sequence of the 1st resistor 41 or the 2nd resistor 42 of the main scanning direction can be made small, the resolution can be raised.

  In the present embodiment, the ridge 38 is provided on the glaze layer 34, and the first heat generation region 31 and the second heat generation region 32 are formed on the surface of the ridge 38. However, the first heat generation region 31 and the second heat generation region 32 may be formed at different positions in the sub-scanning direction of the flat glaze layer 34 where the protrusions 38 are not formed. In this case, a slide mechanism for sliding the pedestal 81 back and forth in the sub-scanning direction may be used instead of the rotation mechanism of the pedestal 81 as in the present embodiment.

  In the present embodiment, when changing the resolution, the thermal print head 10 is rotated or slid while the surface of the heating plate 30 is pressed against the side surface of the platen roller 11. However, the thermal print head 10 may be temporarily rotated or slid in a state where it is separated from the platen roller 11.

DESCRIPTION OF SYMBOLS 10 ... Thermal print head, 11 ... Platen roller, 12 ... Rotating shaft, 13 ... Print medium, 20 ... Heat sink, 21 ... Circuit board, 22 ... Switch, 23 ... Drive element, 24 ... Bonding wire, 25 ... Sealing Resin, 26 ... power source, 30 ... heating plate, 31 ... first heating area, 32 ... second heating area, 33 ... ceramic substrate, 34 ... glaze layer, 35 ... resistor layer, 36 ... electrode layer, 37 ... protection Film layer, 38 ... protrusion, 39 ... connection pad, 41 ... first resistor, 42 ... second resistor, 43 ... third resistor, 51 ... first wire, 52 ... second wire, 61 ... first Common electrode, 62 ... second common electrode, 71 ... individual electrode, 81 ... pedestal, 83 ... pushing tool, 84 ... stopper, 85 ... stopper, 86 ... shaft, 87 ... fixed portion, 88 ... spring

Claims (8)

An insulating substrate having a main surface extending in the main scanning direction;
A first resistor and a second resistor connected in the main scanning direction are arranged in the vertical sub-scanning direction first wiring, at a location to adjacent in the main scanning direction in the second resistor antibody, and the second An arrangement position of the two resistors and the position in the sub-scanning direction are provided at the same position, connected to the second resistor, and the same side in the sub-scanning direction is connected by a second wiring, and the two third resistors are connected in series. A plurality of resistors arranged in the main scanning direction and having a first heat generating region formed by the first resistor and a second heat generating region formed by the second resistor and the third resistor. When,
A first common electrode commonly connected to each of the first resistors of the plurality of resistor groups;
A second common electrode commonly connected to the third resistor farther from each second resistor of the plurality of resistor groups;
For each resistor group, the individual electrodes connected to the second resistor and the third resistor closer to the second resistor ,
A thermal print head comprising: A switch for connecting a power supply for a common electrode to any one of the first common electrode and the second common electrode;
Driving elements connected to the individual electrodes;
A thermal print head comprising: The insulating substrate is formed with ridges having slopes extending in the main scanning direction and extending from the top to both sides in the sub-scanning direction,
3. The thermal print head according to claim 1, wherein each of the first heat generation area and the second heat generation area is provided on a surface of the protrusion. 4.   3. The thermal print head according to claim 2, wherein the first heat generation area and the second heat generation area are provided on a top portion of the ridge and a slope far from the individual electrode of the ridge. 4.   4. The thermal print head according to claim 1, wherein the first resistor, the second resistor, and the third resistor have the same resistance value. 5. .   The interval between the adjacent second resistor and the third resistor and the interval between the adjacent third resistors are all the same, and the first resistor and the second resistor are in the main scanning. The thermal print head according to claim 5, wherein the directional positions are the same.   6. The thermal print head according to claim 5, wherein a width of the third resistor is smaller than that of the second resistor, and a length of the third resistor is longer than that of the second resistor. An insulating substrate having a major surface extending in the main scanning direction, a first resistor and a second resistor connected by the first wiring is arranged in a perpendicular subscanning direction in the main scanning direction, the second resistor antibody The adjacent position in the main scanning direction and the second resistor arrangement position and the sub-scanning direction position are provided at the same position and connected to the second resistor, and the same side in the sub-scanning direction is the second wiring. A plurality of third resistors connected in series and arranged in the main scanning direction and formed by the first resistors, the first heat generating region, the second resistors, and the third resistors; A resistor group having a second heat generating region formed by:
A first common electrode commonly connected to each of the first resistors of the plurality of resistor groups;
A second common electrode commonly connected to the third resistor farther from each second resistor of the plurality of resistor groups;
A thermal print head having, for each resistor group, the second resistor and an individual electrode connected to the third resistor closer to the second resistor;
A platen roller that rotates about a rotation axis parallel to the longitudinal direction of the insulating substrate;
A posture adjusting mechanism that changes the posture of the thermal print head and presses either the first heat generation region or the second heat generation region against the platen roller;
A thermal printer comprising:

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