Thermal print head and printer

Abstract

To provide a thermal print head capable of easily determining whether a substrate part is a regular product or not.SOLUTION: The thermal printer head A1 includes a substrate 1, a resistor layer 4 disposed on the substrate 1 and having a plurality of heat generating portions 41 arranged in a main scanning direction X, common electrodes 31 for supplying a common current to the plurality of heat generating portions 41, and individual electrodes 34 for individually supplying a current to the plurality of heat generating portions 41. The resistance value of at least one of the heat generators 41 is higher than the resistance values of the other heat generators 41.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to a thermal printhead and a printer including the thermal printhead. [Background technology]

[0002] Conventionally, as shown in JP 2023-84582 A (Patent Document 1), a thermal printhead is known that can print on a printing medium by supplying an electric current to a heat generating element formed on a substrate to cause the heat generating element to heat up. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-84582

[0004] [overview] In recent years, there have been cases where the circuit board of a thermal printhead has been replaced with an unauthorized product, as disclosed in Patent Document 1. However, it is not easy to visually determine whether the circuit board of a thermal printhead is genuine or not.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a thermal printhead that makes it possible to easily determine whether the substrate portion is genuine or not.

[0006] The thermal printhead of the present disclosure includes a substrate, a resistor layer disposed on the substrate and having a plurality of heat generating elements arranged in the main scanning direction, a common electrode for supplying a common current to the plurality of heat generating elements, and individual electrodes for supplying individual current to the plurality of heat generating elements, wherein the resistance value of at least one of the plurality of heat generating elements is higher than the resistance values ​​of the other heat generating elements.

[0007] According to the thermal printhead of the present disclosure, the resistance value of at least one of the multiple heating elements is set higher than the resistance values ​​of the other heating elements, so that by detecting the resistance value of the heating element, it is possible to easily determine whether the substrate portion is genuine or not. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a plan view showing a thermal printhead. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 2 is an enlarged plan view of a main part of the thermal printhead. [Figure 4] FIG. 2 is a block diagram showing a portion of the functions of the thermal printer. [Figure 5] 10 is a graph showing the change in resistance value with respect to applied energy. [Figure 6] 10 is a graph showing the relationship between dot number and resistance value. [Figure 7] 4 is a flowchart showing the control content of the control device. [Figure 8] 10 is a graph showing the relationship between the dot number and the resistance value in a modified example. [Figure 9] FIG. 10 is an enlarged plan view of a main part of a thermal printhead according to a modified example.

[0009] [Detailed explanation] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0010] FIG. 1 is a plan view showing a thermal printhead A1. FIG. 2 is a cross-sectional view taken along line II-II in FIG. 1. FIG. 3 is an enlarged plan view of a main portion of the thermal printhead A1. The thermal printhead A1 is a rectangular, flat plate when viewed from above. The X direction (also referred to as the main scanning direction X) shown in FIGS. 1 to 3 is the longitudinal direction of the thermal printhead A1, the Y direction (also referred to as the sub-scanning direction Y) is the lateral direction of the thermal printhead A1, and the Z direction is the thickness direction of the thermal printhead A1. Note that scanning refers to reproducing information to be printed, the main scanning direction is the direction perpendicular to the print output direction, and the sub-scanning direction is the direction parallel to the print output direction.

[0011] The thermal printhead A1 comprises a substrate 1, an electrode layer 3, a resistor layer 4, a connection substrate 5, a plurality of wires 61 and 62, a plurality of driver ICs 7, a protective resin 78, and a heat dissipation member 8. The thermal printhead A1 is incorporated into a thermal printer P1 that prints on a print medium C1 (see FIG. 2). During printing, the print medium C1 is fed in the sub-scanning direction Y.

[0012] The thermal printer P1 (also referred to as printer P1) includes a thermal printhead A1 and a platen roller B1. The platen roller B1 is positioned opposite the thermal printhead A1. A print medium C1 is sandwiched between the thermal printhead A1 and the platen roller B1 and transported in the sub-scanning direction Y by the platen roller B1. Examples of such print media C1 include thermal paper for creating barcode sheets, receipts, etc. A flat platen made of rubber may be used instead of the platen roller B1. The platen includes a portion of a cylindrical rubber with a large radius of curvature that is arcuate in cross section. In this disclosure, the term "platen" includes both the platen roller B1 and a flat platen.

[0013] As shown in Fig. 1, the substrate 1 is a plate-like member that extends elongatedly in the main scanning direction X. An electrode layer 3, a resistor layer 4, and a plurality of driver ICs 7 are provided on the substrate 1. The substrate 1 includes a base material 11 and a glaze layer 12 that is disposed above the base material 11 (in the positive direction of the Z axis). The surface of the substrate 1 is covered with a protective layer (not shown). The protective layer protects the electrode layer 3, the resistor layer 4, and the like.

[0014] The substrate 11 is made of ceramic, such as aluminum nitride, alumina, zirconia, etc. The substrate 11 has a rectangular shape extending long in the main scanning direction X in plan view, as shown in FIG.

[0015] The glaze layer 12 includes a glass material such as amorphous glass. The glaze layer 12 includes a bulging portion 121 and a flat portion 122. The bulging portion 121 has an arc-shaped cross section to facilitate pressing the heat-generating portion of the resistor layer 4 (a heat-generating portion 41, described below) against the print medium C1. The bulging portion 121 also serves as a heat storage layer that accumulates heat from the heat-generating portion 41. The dimension (maximum dimension) of the bulging portion 121 in the thickness direction Z is larger than that of the flat portion 122.

[0016] The flat portion 122 is formed adjacent to the bulging portion 121 and has a flat upper surface. The flat portion 122 covers the surface of the base material 11, which is a relatively rough surface, to form a smooth surface suitable for forming the electrode layer 3.

[0017] The electrode layer 3 forms a conductive path for supplying current to the resistor layer 4. The electrode layer 3 is made of a conductive material. The electrode layer 3 is a metal containing, for example, Au (gold). The electrode layer 3 is formed on the glaze layer 12 of the substrate 1. The electrode layer 3 has a common electrode 31 and a plurality of individual electrodes 34. The shape, arrangement, and material of each part of the electrode layer 3 can be variously configured.

[0018] As shown in FIG. 3, the common electrode 31 has multiple strip-shaped portions 32 and connecting portions 33. The connecting portions 33 are arranged near the edge of the substrate 1 on the positive side in the sub-scanning direction Y and are strip-shaped members extending in the main scanning direction X. The multiple strip-shaped portions 32 each extend from the connecting portion 33 in the sub-scanning direction Y and are arranged at equal intervals in the main scanning direction X. In the example shown in FIG. 3, an Ag layer 331 is laminated on the connecting portion 33 to reduce the resistance of the connecting portion 33, but the Ag layer 331 does not have to be laminated. The resistance value is a numerical representation of the ability to impede the flow of current. The Ag layer 331 is formed, for example, by printing and firing a paste containing an organic Ag (silver) compound or a paste containing Ag (silver) particles, glass frit, Pd (palladium), and resin.

[0019] The plurality of individual electrodes 34 are for partially supplying current to the resistor layer 4. Each individual electrode 34 has an opposite polarity to the common electrode 31. Each individual electrode 34 extends from the resistor layer 4 toward the driver IC 7. The plurality of individual electrodes 34 are arranged in the main scanning direction X. Each of the plurality of individual electrodes 34 has a strip portion 35, a connecting portion 36, and a bonding portion 37.

[0020] 3, the strip portions 35 extend in the sub-scanning direction Y and are strip-shaped when viewed in the thickness direction Z. Each strip portion 35 is located between two adjacent strip portions 32 of the common electrode 31.

[0021] The connecting portion 36 is a portion that extends from the strip portion 35 toward the driver IC 7. The connecting portion 36 includes a parallel portion 361 and an inclined portion 362. One end of the parallel portion 361 is connected to the bonding portion 37, and the parallel portion 361 extends along the sub-scanning direction Y. The inclined portion 362 is inclined with respect to the sub-scanning direction Y. The inclined portion 362 is sandwiched between the parallel portion 361 and the strip portion 35 in the sub-scanning direction Y. The multiple individual electrodes 34 are collected in the driver IC 7.

[0022] 3, the bonding portions 37 are formed at the upstream ends of the individual electrodes 34 in the sub-scanning direction Y, and each is connected to a corresponding parallel portion 361. A wire 61 is bonded to each bonding portion 37. This establishes electrical continuity between each individual electrode 34 and the driver IC 7 via each wire 61. The bonding portions 37 include a first bonding portion 37A and a second bonding portion 37B.

[0023] The second bonding portion 37B is located farther from the resistor layer 4 than the first bonding portion 37A in the sub-scanning direction Y. The second bonding portion 37B is connected to a parallel portion 361 sandwiched between two adjacent first bonding portions 37A. This configuration prevents the multiple bonding portions 37 from interfering with each other, even though they are wider than most portions of the connecting portion 36. The portion of the connecting portion 36 sandwiched between adjacent first bonding portions 37A has the smallest width on the individual electrode 34.

[0024] The resistor layer 4 has a higher resistivity than the material constituting the electrode layer 3. The resistor layer 4 is made of, for example, ruthenium oxide. As shown in FIG. 3, the resistor layer 4 is formed on the bulge portion 121. As shown in FIGS. 1 and 3, the resistor layer 4 is strip-shaped and extends in the main scanning direction X. The resistor layer 4 intersects with each strip portion 32 (common electrode 31) and each strip portion 35 (individual electrode 34). The resistor layer 4 is stacked on the opposite side of the substrate 1 from the multiple strip portions 32 and the multiple strip portions 35 in the thickness direction Z. Portions of the resistor layer 4 sandwiched between each strip portion 32 and each strip portion 35 form heat-generating portions 41.

[0025] The plurality of heat generating portions 41 generate heat when a current is partially supplied by the electrode layer 3. Specifically, a fixed potential is applied to the common electrode 31. A potential is selectively applied to each of the plurality of individual electrodes 34 from the driver IC 7. Therefore, two adjacent heat generating portions 41 connecting the tip end (strip portion 35) of one individual electrode 34 to which the potential is selectively applied and the two tip ends (two strip portions 32) of the common electrode 31 adjacent to the tip end (strip portion 35) of that one individual electrode 34 generate heat when a current is supplied. This heat is transferred to the print medium C1, thereby printing on the print medium C1.

[0026] Two adjacent heat generating elements 41 are also referred to as a dot. Each dot is assigned a number (also referred to as a dot number); for example, in the thermal printhead A1, the dots are assigned dot numbers from 0 to 640. A print dot is formed by the heat generated by each heat generating element 41. The multiple heat generating elements 41 are arranged in the main scanning direction X. The greater the number of multiple heat generating elements 41 arranged in the main scanning direction X per unit length of the substrate 1 in the main scanning direction X, the greater the dot density of the thermal printhead A1. The material and thickness of the resistor layer 4 are not limited.

[0027] As shown in FIGS. 1 and 2, the connection board 5 is disposed upstream of the substrate 1 in the sub-scanning direction Y. The connection board 5 is, for example, a printed circuit board, and has a wiring pattern (not shown) formed thereon. A connector 59 is mounted on the connection board 5. The shape of the connection board 5 is not particularly limited, but in this embodiment, it is rectangular with the main scanning direction X as its longitudinal direction. Note that the connection board 5 may not be provided, and the connection board 5 portion may be formed by the base material 11.

[0028] Each of the multiple driver ICs 7 is mounted on the substrate 1 and selectively applies a potential to each of the multiple individual electrodes 34. The multiple driver ICs 7 supply current to the heat generating elements 41 between adjacent individual electrodes 34. Note that, during printing, current is not supplied to specific heat generating elements 41 by the individual electrodes 34. Each driver IC 7 may be mounted across the substrate 1 and the connection substrate 5, or may be mounted on the connection substrate 5. Each of the multiple driver ICs 7 is connected to the multiple individual electrodes 34 (the multiple bonding portions 37) by multiple wires 61. The multiple driver ICs 7 control the supply of current to the multiple heat generating elements 41 in accordance with a command signal input from outside the thermal printhead A1 via the connection substrate 5. The multiple driver ICs 7 are connected to a wiring pattern (not shown) on the connection substrate 5 by multiple wires 62. The multiple driver ICs 7 are appropriately provided according to the number of the multiple heat generating elements 41.

[0029] The driver ICs 7, the wires 61, and the wires 62 are covered with a protective resin 78. The protective resin 78 is made of, for example, an insulating resin. The protective resin 78 is formed so as to straddle the substrate 1 and the connection substrate 5.

[0030] The connector 59 is used to connect the thermal printhead A1 to a thermal printer. The connector 59 is attached to the connection board 5 and connected to the wiring pattern (not shown) of the connection board 5.

[0031] 2, the heat dissipation member 8 supports the substrate 1 and the connection substrate 5. The heat dissipation member 8 is intended to dissipate some of the heat generated by the plurality of heat-generating portions 41 to the outside via the substrate 1. The heat dissipation member 8 is a block-shaped member made of a metal such as Al.

[0032] 4 is a block diagram showing some of the functions of the thermal printer P1. The thermal printer P1 includes a thermal printhead A1, a control device 100, and an alarm device 105.

[0033] The thermal printhead A1 includes a common electrode 31, a heat generating portion 41, a plurality of individual electrodes 34, and a memory unit 110. The structures of the common electrode 31, the heat generating portion 41, and the individual electrodes 34 are as described above. The memory unit 110 stores position information related to the dot numbers of the heat generating portion 41 and the resistance values ​​corresponding to each dot number.

[0034] The control device 100 includes a calculation unit 101 and a storage unit 102. The calculation unit 101 includes, as functional units, a command unit 103 and a determination unit 104. The calculation unit 101 is a calculation entity (computer) that executes predetermined processing. The calculation unit 101 is configured with a processor such as a central processing unit (CPU), a micro-processing unit (MPU), a tensor processing unit (TPU), or a graphics processing unit (GPU). Note that a processor, which is an example of the calculation unit 101, has the function of executing predetermined processing by executing a predetermined program. However, some or all of these functions may be implemented using dedicated hardware circuits such as an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The term "processor" is not limited to a processor in the narrow sense that executes processing using a stored program, such as a CPU, MPU, TPU, or GPU, but may also include hardwired circuits such as an ASIC or FPGA. Furthermore, the calculation unit 101 is not limited to a von Neumann computer such as a CPU or GPU, but may also be a non-von Neumann computer such as a quantum computer or an optical computer. The calculation unit 101 may also be interpreted as a processing circuit. The calculation unit 101 may be configured on a single chip or multiple chips. Furthermore, the processor and related processing circuits may be configured on multiple computers interconnected by wire or wirelessly via a local area network or a wireless network. The processor and related processing circuits may also be configured as a cloud computer that performs remote calculations based on input information and outputs the calculation results to another device located at a distance. The calculation unit 101 controls the operation of each component of the thermal printer P1 by reading and executing programs stored in the storage unit 102.

[0035] The storage unit 102 is realized by a storage device such as a non-volatile memory such as a random access memory (RAM), a read only memory (ROM), or a flash memory, or a magnetic disk. The storage unit 102 stores programs executed by the calculation unit 101, data used by the calculation unit 101, etc. The storage unit 102 may also be interpreted as a processing circuitry having the function of retaining data or signals. For example, the storage unit 102 stores information such as information related to printing, position information of genuine products related to the dot numbers of the heat generating unit 41, and resistance values ​​of genuine products corresponding to the dot numbers.

[0036] Command unit 103 sends a command to thermal printhead A1 to apply power to the thermal printhead A1 based on the printing-related information stored in memory unit 102. Determination unit 104 compares the position information related to the dot numbers of the heat generating elements 41 stored in memory unit 110 of thermal printhead A1 and the resistance values ​​of the heat generating elements 41 corresponding to each dot number with the genuine product information stored in memory unit 102, and determines whether or not the thermal printhead A1 is genuine.

[0037] The alarm device 105 is a speaker that outputs an alarm sound when the control device 100 determines that the board 1 portion has been replaced with an unauthorized product. The alarm device 105 may be configured to display an image related to the alarm on a display screen (not shown) of the thermal printer P1.

[0038] FIG. 5 is a graph showing the change in resistance value with applied energy. Applied energy is the energy (the product of power and time) provided to heat the heat generating element 41 to the temperature required for printing. The horizontal axis represents applied energy, and the vertical axis represents the rate of change in resistance value in the heat generating element 41. The rate of change in resistance value of the heat generating element 41 indicates the proportion of change in resistance value from a predetermined reference value. Graph E in FIG. 5 shows the change in resistance value with applied energy in the thick-film thermal printhead A1 described in this embodiment. Graph F in FIG. 5 shows the change in resistance value with applied energy in the thin-film thermal printhead. There is a difference in the change in resistance value with applied energy between the thick-film and thin-film types.

[0039] The resistor layer 4 in the thick-film thermal printhead A1 is formed by baking a paste that has been printed in a thick film on the substrate 1. On the other hand, the resistor layer in the thin-film thermal printhead is formed by sputtering. Comparing graphs E and F in Figure 5, the resistance value in neither graph E nor graph F changes significantly when the applied energy is about 0 to 0.08 [mJ / dot].

[0040] However, in graph F, the rate of change in resistance value rises sharply when the applied energy exceeds 0.08 [mJ / dot]. This is due to the destruction of the thin-film dots. On the other hand, in graph E, the rate of change in resistance value gradually increases with increasing applied energy in the range above 0.08 [mJ / dot]. Taking advantage of this property, the thermal printhead A1 is formed so that the resistance value of at least one specific heat generating element 41 in the resistor layer 4 is higher than the resistance values ​​of the other heat generating elements 41.

[0041] For example, a specific heat generating portion 41 in the resistor layer 4 is formed so that the rate of change in resistance value is near the double-ended arrows of the dashed line G in FIG. 5 (about 10% to 40%). Specifically, the specific heat generating portion 41 is formed so that the resistance value is at least 10% higher and not more than 40% higher than the resistance value of the other heat generating portions 41. A value about 15% higher is preferable. 15% is a value similar to the resistance value that serves as the criterion for determining a malfunction.

[0042] The specific heat generating portion 41 is formed, for example, by applying energy equal to or greater than a reference value to the resistor layer 4. Specifically, in the process of setting the resistance value of each heat generating portion 41, the voltage applied to the resistor layer 4 is changed between the specific heat generating portion 41 and the other heat generating portions 41, thereby applying energy equal to or greater than the reference value to the resistor layer 4. In this way, the thermal printhead A1 makes the resistance value of the heat generating portion 41 located at the specific position greater than the resistance values ​​of the other heat generating portions 41.

[0043] 6 is a graph showing the relationship between dot number and resistance value. The horizontal axis shows the dot number corresponding to each dot on the resistor layer 4, and the vertical axis shows the resistance value for each dot. As shown in FIG. 6, the thermal printhead A1, for example, has resistance values ​​at the positions of 0 dot and 640 dot, which are end positions in the main scanning direction X on the resistor layer 4, that are higher than the average resistance value of the other heat generating elements 41. The heat generating elements 41 located at the positions of 0 dot and 640 dot correspond to specific positions on the resistor layer 4 to which no current is supplied by the individual electrodes 34.

[0044] The specific heat generating portion 41 that increases the resistance value may be located at either both ends of the resistor layer 4, at one of both ends, or at a position other than both ends. The number of specific heat generating portions 41 that increase the resistance value may be one or more.

[0045] Next, the control contents executed by the control device 100 will be described with reference to Fig. 7. Fig. 7 is a flowchart showing the control contents of the control device 100. In Fig. 7, the control device 100 determines whether or not it is power-on time in step (hereinafter simply referred to as "S") 1. If the control device 100 determines that it is not power-on time (NO in S1), it ends the processing. If the control device 100 determines that it is power-on time (YES in S1), it proceeds to the processing of S2.

[0046] In S2, the control device 100 acquires the position information and resistance values ​​stored in the memory unit 110 of the thermal printhead A1. When the thermal printer P1 is turned on, the control device 100 applies a potential to the common electrode 31 and the individual electrodes 34 to supply a current, and stores the relationship between the dot numbers of the heat generating elements 41 and the resistance values ​​as shown in Fig. 6 in the memory unit 110. In S2, the control device 100 acquires the position information corresponding to the dot numbers and the resistance values ​​corresponding to the dot numbers.

[0047] Next, the control device 100, in a process executed by the determination unit 104, determines whether the dot at a specific position has the same position information and resistance value as that of a genuine product stored in the memory unit 102 (S3). The process of S3 compares the position information of the genuine product for determination related to the dot number and the resistance value of the genuine product for determination corresponding to the dot number with the position information corresponding to the dot number and the resistance value corresponding to the dot number acquired in S2. The resistance value for determination has a certain range of values, and an acceptable range may be set from the reference value to be determined. For example, if the resistance value of the actual product corresponding to the target dot number exceeds the reference value for the resistance value for determination and is within the acceptable range, the product is genuine; if it is below the reference value or exceeds the acceptable range, the product is non-genuine.

[0048] If the control device 100 determines that the dot at the specific position has the same position information and resistance value as the genuine product stored in the memory unit 102 (YES in S3), it sets the thermal printer P1 to a usable state in S4 and ends the process. The YES process in S3 is a process of determining that the product is genuine if the acquired position information and resistance value of the actual product are the position information and resistance value for determination.

[0049] On the other hand, if the control device 100 determines that the dot at the specific position does not have the same position information and resistance value as the genuine product stored in the memory unit 102 (NO in S3), it outputs an alarm from the alarm device 105 (S5) and ends the process. The NO process in S3 is a process of determining that the product is non-genuine if the acquired position information and resistance value of the actual product are not the position information and resistance value for determination.

[0050] In the thermal printhead A1, among the multiple heat generating elements 41, the resistance value of the heat generating element 41 at a specific position is higher than the resistance value of the other heat generating elements 41. Therefore, by detecting the resistance value of the heat generating element 41 at the specific position, it is possible to easily determine whether or not the substrate 1 portion is genuine. The specific position is the end position in the main scanning direction X of the resistor layer 4. No current is supplied to the heat generating element 41 at the specific position by the individual electrode 34. By using the heat generating element 41 at such a specific position, it is possible to determine whether or not the product is genuine using information from the heat generating element 41 that does not affect printing.

[0051] [Variation] Next, a modified example of the thermal printhead A1 will be described. FIG. 8 is a graph showing the relationship between dot number and resistance value in this modified example. FIG. 8(a) shows the graph when no failure occurs, and FIG. 8(b) shows the graph when a failure occurs. The modified thermal printhead A1 shown in FIG. 8(a) has higher resistance values ​​at dots 0 to 4 and dots 636 to 640, which are end positions in the main scanning direction X of the resistor layer 4. In other words, the modified thermal printhead A1 has higher resistance values ​​for the five dots at both ends of the multiple heat generating elements 41 than the average resistance value of the other heat generating elements 41. In this way, a certain range may be set for the dots whose resistance values ​​are changed.

[0052] The dots on graph S in Figure 8(b) indicate an increase in resistance due to a malfunction. As shown in Figure 8, the dots at both ends where the resistance was increased to determine whether the product was genuine and the dots on graph S where the resistance was increased due to a malfunction appear to be of the same magnitude on the graph. Therefore, even if a third party attempts to check the resistance after replacing the thermal printhead A1, the heat generating element 41 at a specific location simply appears to have an increased resistance due to a malfunction. This makes it difficult for a third party to determine whether the heat generating element 41 at a specific location is determining whether the product is genuine, thereby effectively preventing replacement with an ungenuine product. Note that, because the increase in resistance due to a malfunction is at most about 15% of the average, the dots used to determine whether the product is genuine can also be generated so that their resistance increases within a similar range.

[0053] Figure 9 is an enlarged plan view of a main portion of a thermal printhead A1 according to a modified example. As shown in Figure 9, the thermal printhead A1 according to the modified example includes dummy electrodes 38 located outside the individual electrodes 34 and not connected to the individual electrodes 34. A dummy heat generating portion 39 not connected to the individual electrodes 34 is formed between the common electrode 31 and the dummy electrodes 38. The dummy heat generating portion 39 may be used to determine whether the product is genuine. In this way, the determination of whether the product is genuine can be performed without affecting printing.

[0054] By attaching a serial number or the like to the substrate 1 in the above-described embodiment, it becomes easier to determine whether the thermal printhead A1 is a genuine product, thereby improving security.

[0055] The thermal printhead A1 may not necessarily be provided with the memory unit 110. In such a case, when the thermal printer P1 is turned on, the control device 100 can directly detect the position information corresponding to the dot numbers of the thermal printhead A1 and the resistance values ​​corresponding to the dot numbers. The position information corresponding to the dot numbers of the thermal printhead A1 and the resistance values ​​corresponding to the dot numbers may also be stored in the memory unit 102 of the thermal printer P1 at a predetermined timing.

[0056] A dot number may be assigned to each heat generating portion 41 (half dot), and whether or not the substrate 1 portion is genuine may be determined based on genuine product position information relating to the dot number and genuine product resistance value information corresponding to the dot number.

[0057] Various aspects of the present disclosure are summarized below as appendices. [Note] (1) A thermal printhead A1 of the present disclosure includes a substrate 1, a resistor layer 4 disposed on the substrate 1 and having a plurality of heat generating portions 41 arranged in the main scanning direction X, a common electrode 31 that supplies a common current to the plurality of heat generating portions 41, and individual electrodes 34 that supply current individually to the plurality of heat generating portions 41. The resistance value of at least one of the plurality of heat generating portions 41 is higher than the resistance values ​​of the other heat generating portions 41.

[0058] According to this configuration, by detecting the resistance value of the heat generating portion 41, it is possible to easily determine whether the substrate 1 portion is a genuine product or not.

[0059] (2) In the thermal printhead A1 described in (1), the resistor layer 4 is formed by baking a paste that has been printed as a thick film on the substrate 1.

[0060] According to this configuration, the resistor layer 4 can be formed by thick film printing.

[0061] (3) In the thermal printhead A1 described in (1) or (2), at least one heat generating portion 41 is disposed at a specific position on the resistor layer 4 to which no current is supplied by the individual electrodes 34 during printing.

[0062] According to this configuration, it is possible to determine whether or not a product is genuine by using the heat generating portion 41 at a specific position that is not used for printing.

[0063] (4) In the thermal printhead A1 described in (3), the specific position includes the position of the end of the resistor layer 4 in the main scanning direction X.

[0064] According to this configuration, it is possible to determine whether or not the product is genuine by using the heat generating portion 41 at the end position in the main scanning direction X that is not used for printing.

[0065] (5) In the thermal printhead A1 described in any one of (1) to (4), at least one heat generating portion 41 includes a dummy heat generating portion 39 that is not connected to an individual electrode .

[0066] According to this configuration, it is possible to determine whether or not a product is genuine by using the dummy heat generating portion 39 that is not used for printing.

[0067] (6) In the thermal printhead A1 described in any one of (1) to (5), the resistance value of at least one heat generating element 41 is 10% or more of the resistance value of the other heat generating elements 41.

[0068] According to this configuration, by checking the resistance value of at least one heat generating portion 41, it is possible to determine whether the product is genuine or not.

[0069] (7) In the thermal printhead A1 described in any one of (1) to (6), at least one heat generating portion 41 is formed by applying energy to the resistor layer 4 that is equal to or greater than a reference value.

[0070] According to this configuration, at least one heat generating portion 41 can be formed by applying energy to the resistor layer 4 that is equal to or greater than a reference value.

[0071] (8) The thermal printhead A1 according to any one of (1) to (7) further comprises a storage unit 110 for storing position information of at least one heat generating element 41 and the resistance value of at least one heat generating element 41.

[0072] With this configuration, it is possible to determine whether the product is genuine or not based on the information stored in the storage unit 110.

[0073] (9) A printer P1 of the present disclosure includes a thermal printhead A1 described in any one of (1) to (8) and a control device 100 that determines whether the thermal printhead A1 is genuine based on the position information and resistance value stored in a memory unit 110.

[0074] With this configuration, the control device 100 can determine, based on the position information and resistance value stored in the storage unit 110, whether the thermal printhead A1 is a genuine product.

[0075] (10) A printer P1 of the present disclosure includes a thermal printhead A1 described in any one of (1) to (8), a memory unit 102 that stores position information of at least one heat generating element 41 and a resistance value of at least one heat generating element 41, and a control device 100 that determines whether the thermal printhead A1 is genuine based on the position information and resistance value stored in the memory unit 102.

[0076] With this configuration, the control device 100 can determine whether the thermal printhead A1 is a genuine product based on the position information and resistance value stored in the storage unit 102.

[0077] Although the embodiments of the present disclosure have been described above, the above-described embodiments can be modified in various ways. Furthermore, the scope of the present disclosure is not limited to the above-described embodiments. The scope of the present disclosure is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0078] 1 substrate, 3 electrode layer, 4 resistor layer, 5 connection substrate, 8 heat dissipation member, 11 base material, 12 glaze layer, 31 common electrode, 34 individual electrode, 37 bonding section, 38 dummy electrode, 39 dummy heat generating section, 41 heat generating section, 59 connector, 100 control device, 101 calculation section, 102, 110 memory section, 103 command section, 104 judgment section, 105 alarm device, A1 thermal print head, B1 platen roller, C1 printing medium, P1 thermal printer.

Claims

1. A substrate; a resistor layer disposed on the substrate and having a plurality of heat generating portions arranged in a main scanning direction; a common electrode for supplying a common current to the plurality of heat generating portions; individual electrodes for individually supplying current to the plurality of heat generating portions; A thermal printhead, wherein at least one of the plurality of heat generating portions has a higher resistance value than the other heat generating portions.

2. 2. The thermal printhead according to claim 1, wherein the resistor layer is formed by baking a paste that has been thick-film printed on the substrate.

3. 3. The thermal printhead according to claim 1, wherein the at least one heat generating portion is disposed at a specific position on the resistor layer to which no current is supplied by the individual electrode during printing.

4. 4. The thermal printhead according to claim 3, wherein the specific position includes a position of an end of the resistor layer in the main scanning direction.

5. 3. The thermal printhead according to claim 1, wherein the at least one heat generating portion includes a dummy heat generating portion that is not connected to the individual electrode.

6. 3. The thermal printhead according to claim 1, wherein the resistance value of the at least one heat generating portion is 10% or more of the resistance value of the other heat generating portions.

7. 3. The thermal printhead according to claim 1, wherein the at least one heat generating portion is formed by applying energy equal to or greater than a reference value to the resistor layer.

8. 3. The thermal printhead according to claim 1, further comprising a storage unit that stores position information of said at least one heat generating element and a resistance value of said at least one heat generating element.

9. The thermal printhead according to claim 8; a control device that determines whether the thermal printhead is a genuine product based on the position information and the resistance value stored in the memory unit.

10. a thermal printhead according to claim 1 or 2; a storage unit that stores position information of the at least one heat generating portion and a resistance value of the at least one heat generating portion; a control device that determines whether the thermal printhead is a genuine product based on the position information and the resistance value stored in the memory unit.

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