High-Resolution Thermal Print Head and Its Applications

Abstract

The present invention relates to the technical field of thermal printhead manufacturing, specifically a high-resolution thermal printhead that can meet the requirements of high-resolution printing and has strong power resistance performance and its application. Two or more heating resistance units are arranged in two parallel rows as odd-numbered heating elements and even-numbered heating elements. Among them, the heating resistance units in the odd-numbered heating elements and the heating resistance units in the even-numbered heating elements are staggered, so that the gaps between the heating resistance units in the odd-numbered heating elements and the heating resistance units in the even-numbered heating elements are aligned, and the gaps between the heating resistance units in the even-numbered heating elements and the heating resistance units in the odd-numbered heating elements are aligned. In the main printing direction of the odd-numbered heating elements and the even-numbered heating elements, the center distance between two adjacent heating resistance units is equal to the pitch between two adjacent pixel points, thereby effectively enhancing the power resistance performance of a single heating resistance unit and improving product quality.

Description

Technical Field:

[0001] The present invention relates to the technical field of thermal printhead manufacturing, and specifically relates to a high-resolution thermal printhead that can meet the high-resolution printing requirements and has strong electric power resistance performance, and its application. Background Art:

[0002] As is well known, the existing thermal printhead is as shown in the attached Figure 2 It includes an insulating substrate, a bottom glaze layer is provided on the surface of the insulating substrate, a common electrode and individual electrodes are provided on the surface of the insulating substrate and the bottom glaze layer, a heating resistor body is arranged between the two electrodes, one end of the common electrode is connected to the heating resistor body, and the other end is used to be connected to a power supply; one end of the individual electrode is connected to the heating resistor body, and the other end is connected to an IC; an insulating glass glaze protection layer is provided on the surfaces of the heating resistor body, the individual electrode and the common electrode. The heating resistor body is composed of a plurality of heating resistor units. Among them, the heating resistor units in the heating resistor body of the existing thermal printhead are arranged in a straight line in the main printing direction.

[0003] When high-resolution content needs to be printed, the arrangement density of the corresponding heating resistor units is large, the dot pitch between the heating points formed by the heating resistor units is small, and the volume of a single heating element can only be made very small. In a thermal printhead manufactured by a thin film process, the smaller the volume of a single heating element, the worse its electric power resistance performance. Taking a 300 DPI product as an example, its electric power resistance performance is about 2 / 3 of that of a 200 DPI product, and a 600 DPI product is about 1 / 2 of a 300 DPI product. Moreover, there are gaps between points. During the printing process, to ensure good printing effects, more heat is required to make the gaps develop color. Therefore, for a 600 DPI product, due to its very poor electric power resistance ability, it is very easy to cause problems of damage due to large energy during user use. Summary of the Invention:

[0004] The present invention aims at the disadvantages and deficiencies existing in the prior art, and provides a high-resolution thermal printhead that can meet the high-resolution printing requirements, has strong electric power resistance performance, and has no gaps between adjacent points in the main printing direction, and its application.

[0005] The present invention is achieved by the following measures:

[0006] A high-resolution thermal print head is provided with an insulating substrate, and a bottom glaze layer is provided on the surface of the insulating substrate. A wire layer is provided on the surface of the insulating substrate and the bottom glaze layer. The wire layer includes a common electrode and individual electrodes. One end of the common electrode is connected to a heating resistor body, and the other end is connected to a power supply. One end of an individual electrode is connected to the heating resistor body, and the other end is connected to an IC. Two or more heating resistor units are arranged at equal intervals along the main printing direction in the heating resistor body. It is characterized in that the two or more heating resistor units are arranged in two parallel rows as odd-numbered heating elements and even-numbered heating elements. The heating resistor units in the odd-numbered heating elements and the heating resistor units in the even-numbered heating elements are staggered, so that the gaps between the heating resistor units in the odd-numbered heating elements and the heating resistor units in the even-numbered heating elements are aligned, and the gaps between the heating resistor units in the even-numbered heating elements and the heating resistor units in the odd-numbered heating elements are aligned. In the main printing direction, the center distance between two adjacent heating resistor units of the odd-numbered heating elements and the even-numbered heating elements is equal to the pitch between two adjacent pixel points.

[0007] In the present invention, the two rows of heating elements corresponding to the odd-numbered heating elements and the even-numbered heating elements are both connected to the same common electrode to enable the two rows of heating elements to work simultaneously.

[0008] In the present invention, the volume of the heating resistor body unit is larger than the volume of each heating resistor body unit of a single-row heating element with the same resolution. The volume M of the heating resistor body is M = m(1 + b), where m is the volume of each heating resistor body unit in a single-row heating element with the same resolution, and b is a correction coefficient. The value range of b is 21% - 41%. Further preferably, the dimension of the heating resistor body in the main printing direction is enlarged by b, and the value range of b is 30% ± 5%. The length of the heating resistor body unit in the main printing direction extends by m·b / 2 to both sides respectively, thereby improving the power resistance effect of the heating element and making up for the deficiency of insufficient color development in the gaps between traditional adjacent heating points.

[0009] In the present invention, the IC controls the on / off state of a single heating resistor unit according to the printing content. First insulating protective layers are provided on the surfaces of the individual electrodes and the common electrode and near the heating resistor body. This protective layer has good thermal conductivity and electrical insulation.

[0010] In the present invention, the heating resistor body of the print head is changed from a single row to two staggered rows arranged according to odd and even numbers, and are respectively controlled by odd and even points on the control IC. The resolution of each row of heating elements is half of the resolution of the print head. The heating points of the two rows of heating elements are staggered. When the two rows of heating elements act on the same row printing area on the printing medium, a resolution twice that of each row of heating elements will be printed. The volume of the heating resistor body unit corresponding to each heating point will be much larger than that of each heating element of a single row of heating elements with the same resolution, and the withstand voltage will also increase accordingly. When printing, the print content data needs to be divided into two groups according to odd and even numbers, and then recombined into new data according to the distance between the two rows of heating elements in the sub-printing direction and sent to the control IC for printing.

[0011] The present invention also proposes an application of the high-resolution thermal print head as described above, which is characterized by including the following steps:

[0012] Step 1: The IC obtains external print data and judges the line spacing a of the resolution in the original print data and the spacing A between the two rows of heating elements in the current thermal print head. If A is an integer multiple of a, execute Step 2; otherwise, execute Step 3.

[0013] Step 2: When the spacing between the two rows of heating elements in the current thermal print head is an integer multiple of the line spacing of the resolution in the original print data, perform the following operations:

[0014] Step 2-1: Adjust the print control signal: Divide the external original print data into two groups according to odd and even numbers. Each group of data maintains the same number of digits as the original print data. The positions corresponding to the even-digit data in the original print data in the odd-numbered group data are filled with 0, and the positions corresponding to the odd-digit data in the original print data in the even-numbered group data are filled with 0.

[0015] Step 2-2: Send the processed print control signal to the IC row by row to start printing. At this time, only the first row of heating elements works. Each time the printing medium moves a row distance and prints once. When printing the first N rows, where N is the multiple of the spacing between the two rows of heating elements in the current thermal print head and the line spacing of the resolution in the original print data, the print data sent to the IC is the data corresponding to the number of rows of the data group corresponding to the first row of heating elements (either only the odd-numbered group or only the even-numbered group). When starting to print the (N + 1)th row, the two rows of heating elements work simultaneously. The print data sent to the IC is the control data of the two rows of heating elements: that is, a new row of data recombined from the data of the (N + 1)th row of the first group of data and the data of the first row of the second group of data. The two rows of heating elements respectively print the corresponding odd and even bits of their corresponding rows until when the first group of data completes the last row of printing, the second group of data still needs to print N rows to end the printing, and the print data is the data corresponding to the number of rows of the second group of data.

[0016] Step 3: When the distance A between two rows of heating elements in the secondary printing direction is not an integer multiple of the resolution line pitch a defined by the print head, perform the following steps:

[0017] Step 3-1: Divide the original print data into two groups according to odd and even bits. Each group has the same number of bits as the original print data. The odd-numbered group data fills the positions corresponding to the original even data with 0, and the even-numbered group data fills the positions corresponding to the odd data of the original print data with 0;

[0018] Step 3-2: The two rows of heating elements work simultaneously. The printing medium moves one line distance for each print. When the printing medium passes through the two rows of heating elements, when the corresponding position of the printing medium passes through the first row of heating elements, the IC receives the first group of data of the current row corresponding to the first row of heating elements, and the first row of heating elements completes the printing of the odd or even bits of the current row accordingly. When the corresponding position passes through the second row of heating elements, the IC receives the second group of data of the current row corresponding to the second row of heating elements, and the second row of heating elements completes the printing of the even or odd bits of the current row. The two rows of heating elements work alternately. When the same row position on the medium passes through the two rows of heating elements in sequence, the printing of this row is completed. After the entire printing content passes through the two rows of heating elements, the entire printing process is completed.

[0019] In the present invention, the heating resistance elements of the print head are arranged from the original single row into two staggered rows according to odd and even numbers, and are respectively controlled by odd and even points on the control IC. The resolution of each row of heating elements is half of the print head resolution. The size of each corresponding heating resistance element unit in the main printing direction and the secondary printing direction does not exceed the dot pitch corresponding to the resolution defined by the print head. And overall, the center distance between two adjacent heating elements in the main printing direction of the two rows of heating elements is equal to the adjacent two pixel point pitches. During the printing process, the volume of the heating element corresponding to each heating resistance element unit will be much larger than that of each heating element of the single-row heating element with the same resolution, thereby effectively enhancing the power resistance performance of a single heating resistance element unit and improving product quality. Brief Description of the Drawings:

[0020] Att Figure 1 is a schematic diagram of the working state of the present invention.

[0021] Att Figure 2 is a schematic diagram of the structure of the existing thermal print head.

[0022] Att Figure 3 is a schematic diagram of the structure of the thermal print head in the present invention.

[0023] Att Figure 4 is a schematic diagram of the process of grouping and processing the original print data according to odd and even numbers in the present invention and the corresponding relationship between the control points in the IC and the heating elements.

[0024] Att Figure 5Schematic diagram of the high-resolution printing operation of the thermal print head in Embodiment 1 of the present invention.

[0025] Appendix Figure 6 Schematic diagram of the printing operation of the thermal print head in Embodiment 2 of the present invention.

[0026] Reference numerals: 1 - common electrode, 2 - second row of heating elements, 3 - first row of heating elements, 4 - individual electrode, 5 - IC, 6 - bonding pad on the substrate, 7 - bonding pad on the IC, 8 - bonding wire, 9 - heating element of the ordinary print head, 10 - heat dissipation substrate, 11 - insulating substrate, 12 - bottom glaze layer, 13 - wire layer, 14 - first insulating protective layer, 15 - printing medium, 16 - rubber roller. Specific embodiments:

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Embodiment 1:

[0029] As shown in the appendix Figure 3 In this example, a high-resolution thermal print head is proposed. A heat dissipation substrate 10 is provided, an insulating substrate 11 is provided on the heat dissipation substrate 10, a bottom glaze layer 12 is provided on the surface of the insulating substrate 11 in whole or in part, a wire layer 13 is provided on the surface of the insulating substrate 11 and the bottom glaze layer 12, and the wire layer 13 is composed of a common electrode 1 and an individual electrode 2. One end of the common electrode 1 is connected to the heating resistor 9, and the other end is connected to the power supply; one end of the individual electrode 2 is connected to the heating resistor 9, and the other end is connected to the IC 5. The IC 5 can control the on / off of a single point according to the printing content. A first insulating protective layer 14 is provided near the heating elements on the surfaces of the individual electrode 2 and the common electrode 1. This protective layer has good thermal conductivity and electrical insulation. The above structure is a common structure of the print head;

[0030] When high-resolution content needs to be printed, a large density of heating points and a small pitch between points are required. This results in a very small volume for a single heating element of the print head made by thin-film technology, and the smaller the volume of a single heating element of the print head made by thin-film technology, the worse the withstand voltage. In this example, the heating elements 9 of the print head are arranged in two rows in an alternating pattern according to odd and even numbers from one row as Figure 3As shown, both rows of heating elements are connected to the same common electrode 1. The two rows of heating elements are controlled by the odd-numbered points and even-numbered points on the control IC5 respectively. The resolution of each row of heating elements is half of the printhead resolution. The size of the heating element at each point does not exceed the dot pitch corresponding to the resolution defined by the printhead in both the main printing direction and the sub-printing direction. Overall, the center distance between two adjacent heating elements in the main printing direction of the two rows of heating elements is equal to the adjacent two pixel pitches. The two rows of heating elements are evenly staggered. Looking from the sub-printing direction, the corresponding two adjacent points on the front and back rows of heating elements do not overlap, and there is no gap between two adjacent points when looking from the main printing direction. After that, when the two rows of heating elements act on the same row of the printing medium, a resolution twice that of each row of heating elements will be printed;

[0031] In this example, the volume of the heating resistance unit corresponding to each heating point is designed to be larger than that of each heating element of a single-row heating element with the same resolution. Specifically, the volume M of each heating resistance unit in this example is M = m(1 + b), where m is the volume of each heating resistance unit in a single-row heating element with the same resolution, and b is 30%. The length of the heating resistance unit in the main printing direction extends by 15%·m on both sides, thereby improving the power resistance effect of the heating element and making up for the shortcoming of insufficient color development in the gap between traditional adjacent heating points.

[0032] When the size in the main printing direction is increased by about 30%, the power resistance will also increase correspondingly;

[0033] When the high-resolution thermal printhead described in this example is printing, the print content data needs to be divided into two groups according to odd and even numbers. The specific grouping method is as Figure 4 , replace the corresponding even bits of each line of print data with 0 to form an odd-numbered group of data, and replace the odd bits of the original data with 0 to form an even-numbered group of data. In this example, the first row of heating elements 3 corresponds to the odd bits, and the second row of heating elements 2 corresponds to the even bits. During printing, the printing medium 15 is pressed onto the upper sides of the first row of heating elements 3 and the heating elements 2 by the rubber roller 16, and the rubber roller 16 rotates to drive the printing medium 15 to move forward until all the content is printed;

[0034] Such as Figure 5As shown, when printing in this example, the distance between the two rows of heating elements in the sub-printing direction is equal to the distance between two rows corresponding to the resolution of the print head, that is, an integer multiple of 1 times. The printed content is the capital letter B. The original print data is 7×7 data. The original data is divided into two groups according to odd and even numbers. Each group has the same number of digits as the original print data. The odd-numbered group data fills 0 in the positions corresponding to the original even-numbered data, and the even-numbered group data is the same. After grouping, two groups of 7×7 data are obtained. The odd-numbered group data in the Nth row is abbreviated as N-1 data, and the even-numbered group data in the Nth row is abbreviated as N-2 data. When the first row position on the printing medium 15 passes through the first row of heating elements 3 of the print head, 1-1 data is sent to the control IC5 to control the print head to print. When the second row position on the printing medium 15 passes through the first row of heating elements 3, the first row position on the printing medium 15 just passes through the second row of heating elements 2. At this time, the two rows of heating elements need to work simultaneously. The 2-1 print data and the 1-2 print data need to be added and combined into a new line of data and then sent to the control IC5 to control the printing. Print the combination of 3-1 data and 2-2 data, 4-1 data and 3-2 data, 5-1 data and 4-2 data, 6-1 data and 5-2 data, 7-1 data and 6-2 data in turn. Until the last row position of the printing medium 15 passes through the second row of heating elements 2 of the print head, 7-2 data is sent to the control IC5 to control the printing. After this row of printing is completed, the entire printing process is completed.

[0035] Embodiment 2:

[0036] The structure and data grouping method of the high-resolution thermal print head described in this example are the same as those in Embodiment 1. In this example, the distance between the two rows of heating elements in the thermal print head is not an integer multiple of the resolution row spacing in the original print data. Here, 1.5 times is taken as an example. When printing, the following operations are performed:

[0037] Such as Figure 6As shown, the printed content in this embodiment is the capital English letter B. The original print data is 7×7 data. The original data is divided into two groups according to odd and even numbers. Each group has the same number of digits as the original print data. The positions corresponding to the original even data in the odd-numbered group data are filled with 0s, and the same applies to the even-numbered group data. After grouping, two groups of 7×7 data are obtained. The odd-numbered group data in the Nth row is abbreviated as N-1 data, and the even-numbered group data in the Nth row is abbreviated as N-2 data. When the first row position on the printing medium 15 passes through the first row of heating elements 3 of the print head, 1-1 data is sent to the control IC5 to control the print head to print. When the second row position on the printing medium 15 passes through the first row of heating elements 3, 2-1 data is sent to the control IC to control the print head to print. Continue to feed the paper. When the paper moves forward by half of the resolution line pitch, the first row position on the printing medium 15 is just passing through the second row of heating elements 2, and 1-2 data is sent to the control IC to control the print head to print. Continue to feed the paper. When the third row position on the printing medium 15 passes through the first row of heating elements 3, 3-1 data is sent to the control IC5 to control the print head to print, and so on. When the second row of the printing medium passes through the second row of heating elements 2, 2-2 data is sent to the control IC to control the print head to print. In this way, the two rows of heating elements on the print head print alternately, and each row position on the printing medium prints its corresponding data until the entire printing is completed. It should be noted that the heating time for each row of printing by this method must be less than half of the row cycle time.

[0038] Compared with the prior art, the volume of the heating element corresponding to each heating resistor unit of the present invention will increase by about 30% compared to the volume of each heating element of a single-row heating element with the same resolution, thereby effectively enhancing the power resistance performance of a single heating resistor unit and improving product quality. Moreover, the structure of the two rows of heating elements alternating can ensure that there are no gaps between points in the main printing direction, and the printing effect is better.

Claims

1. Application of a high-resolution thermal print head, wherein the high-resolution thermal print head is provided with an insulating substrate, a bottom glaze layer is provided on the surface of the insulating substrate, a conductive wire layer is provided on the surface of the insulating substrate and the bottom glaze layer, the conductive wire layer includes a common electrode and individual electrodes, one end of the common electrode is connected to a heating resistor body, and the other end is connected to a power supply; one end of the individual electrode is connected to the heating resistor body, and the other end is connected to an IC. Two or more heating resistor units arranged at equal intervals along the main printing direction are provided in the heating resistor body, and it is characterized in that, The above two or more heating resistance units are arranged in two parallel rows as odd-numbered heating elements and even-numbered heating elements, wherein the heating resistance units in the odd-numbered heating elements and the heating resistance units in the even-numbered heating elements are arranged in an interleaved manner. In the main printing direction, the center distance between two adjacent heating resistance units in the odd-numbered heating elements and the even-numbered heating elements is equal to the pitch between two adjacent pixel points. The two rows of heating elements are evenly staggered. When the two rows of heating elements act on the same row of the printing medium, a resolution twice that of each row of heating elements will be printed. It is characterized in that the application of the high-resolution thermal print head includes the following steps: Step 1: The IC obtains external printing data and judges the row pitch a of the resolution in the original printing data and the pitch A between the two rows of heating elements in the current thermal print head. If A is an integer multiple of a, go to Step 2; otherwise, go to Step 3. Step 2: When the pitch between the two rows of heating elements in the current thermal print head is an integer multiple of the row pitch of the resolution in the original printing data, perform the following operations: Step 2-1: Adjust the printing control signal: Divide the external original printing data into two groups according to odd and even numbers, and each group of data retains the same number of bits as the original printing data. The positions corresponding to the even-bit data in the original printing data in the odd-numbered data group are filled with 0s, and the positions corresponding to the odd-bit data in the original printing data in the even-numbered data group are filled with 0s. Step 2-2: Send the processed printing control signal to the IC row by row to start printing. At this time, only the first row of heating elements works. Each time the printing medium moves one row distance and prints once. When printing the first N rows, where N is the multiple of the pitch between the two rows of heating elements in the current thermal print head and the row pitch of the resolution in the original printing data, the printing data sent to the IC is the data corresponding to the row number of the data group corresponding to the first row of heating elements. The data group is only the data corresponding to the row number of the odd-numbered data group or the even-numbered data group. When starting to print the (N + 1)th row, the two rows of heating elements work simultaneously, and the printing data sent to the IC is the control data of the two rows of heating elements: that is, a new row of data recombined from the data of the (N + 1)th row of the first group of data and the data of the first row of the second group of data. The two rows of heating elements print the corresponding odd and even bits of their respective corresponding rows until when the first group of data finishes printing the last row, the second group of data still needs to print N rows to end the printing, and the printing data is the data corresponding to the row number of the second group of data. Step 3: When the pitch A between the two rows of heating elements in the secondary printing direction is not an integer multiple of the row pitch a defined by the print head, perform the following steps: Step 3-1: Divide the original printing data into two groups according to odd and even bits, and each group of data has the same number of bits as the original printing data. The positions corresponding to the even-bit data in the original printing data in the odd-numbered data group are filled with 0s, and the positions corresponding to the odd-bit data in the original printing data in the even-numbered data group are filled with 0s. Step 3-2: The two rows of heating elements work simultaneously. The printing medium moves one line distance for each print. When the printing medium passes through the two rows of heating elements, when the corresponding position of the printing medium passes through the first row of heating elements, the IC receives the first set of data of the current row corresponding to the first row of heating elements, and the first row of heating elements completes the printing of the odd or even positions of the current row accordingly. When the corresponding position passes through the second row of heating elements, the IC receives the second set of data of the current row corresponding to the second row of heating elements, and the second row of heating elements completes the printing of the even or odd positions of the current row. The two rows of heating elements work alternately. When the same row position on the printing medium passes through the two rows of heating elements in sequence, the printing of this row is completed. After the entire printing content passes through the two rows of heating elements, the entire printing process is completed.

2. The application of a high-resolution thermal print head according to claim 1, wherein, In the high-resolution thermal print head, the two rows of heating elements corresponding to the odd-position heating elements and the even-position heating elements are both connected to the same common electrode to enable the two rows of heating elements to work simultaneously.

3. The application of a high-resolution thermal print head according to claim 1, wherein, In the high-resolution thermal print head, the volume M of the heating resistance unit is M = m(1 + b), where m is the volume of each heating resistance unit in a single row of heating elements with the same resolution, and b is the correction coefficient, and the value range of b is 21% - 41%.

4. The application of a high-resolution thermal print head according to claim 3, characterized in that, In the high-resolution thermal print head, the dimension of the heating resistance unit in the main printing direction is enlarged by b·m, the value range of b is 30% ± 5%, and the length of the heating resistance unit in the main printing direction extends by m·b / 2 on both sides respectively.

5. The application of a high-resolution thermal print head according to claim 1, characterized in that, In the high-resolution thermal print head, the IC controls the on / off state of a single heating resistance unit according to the printing content. First insulating protective layers are provided on the surfaces of the individual electrodes and the common electrode as well as near the heating resistance body. The first insulating protective layer has good thermal conductivity and is electrically insulating.

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