A printing method suitable for thermal printing head for two-color printing

Abstract

The present invention relates to the technical field of thermal print head manufacturing, and in particular to a thermal print head suitable for two-color printing and a printing method, characterized in that more than two heating resistors in the heating resistor body are arranged in parallel in two rows along the main printing direction, more than two heating resistors in the same row have the same resistance value, and two heating resistors in different rows have different resistance values, each heating unit is composed of two heating resistors arranged front and back in the secondary printing direction, a control IC is respectively connected to the heating resistors in each heating unit, and control signals of the two heating resistors in any heating unit are sent out by two independent Ton control signal output terminals in the control IC. Compared with the prior art, during the printing process, the thermal print head can output two color development temperatures with obvious differences according to different color development temperature requirements, thereby fundamentally solving the problems of blurring and color mixing in two-color printing.

Description

Technical field:

[0001] The invention relates to the technical field of thermal print head manufacturing, in particular to a thermal print head suitable for two-color printing and a printing method capable of overcoming the problems of color blurring and mixing in existing two-color printing. Background technology:

[0002] As is known to all, the existing thermal print head includes an insulating substrate, a base glaze layer is provided on the surface of the insulating substrate, a bonding electrode, a common electrode and an individual electrode are provided on the surface of the insulating substrate and the base glaze layer, a heating resistor is arranged between the two electrodes, one end of the common electrode is connected to the heating resistor, 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, and the bonding electrode is connected to the IC; an insulating glass glaze protective layer is provided on the surface of the heating resistor, the individual electrode and the common electrode, wherein the direction parallel to the heating resistor belt is called the main printing direction, and the direction perpendicular to the heating resistor belt on the same plane is called the secondary printing direction.

[0003] In the application of two-color printing, the temperature of the heating element needs to be controlled at two levels. For example, if the existing two-color thermal paper is red at about 180°C and black at about 220°C, the color temperature of the thermal print head needs to be controlled at 180°C and 220°C to complete the two-color printing. The existing patent document JP2013195308 discloses a color printer and a heating pulse control method for a color printer, which controls the heating time of different color points by transmitting data multiple times and multiple pulses to control the temperature of the heating point, thereby realizing printing multiple colors. JP1997344506 discloses a thermal head control circuit and a thermal head control method with multi-color printing, and provides a thermal head control circuit and a thermal head control method, which can always perform multi-color printing at a constant speed without reducing the printing speed. Each heating resistor is used to switch the size of the current running in the conductive circuit according to the printing data, and the current switch circuit 5a, 5b, 5c according to the coloring data. JP2011143722A performs multi-color printing by controlling different temperatures and times.

[0004] It can be seen that traditional print heads need to rely on software algorithms to control the opening time of each heating point to control the heating temperature. The entire process relies entirely on software, which is very difficult. Without feedback, it is difficult to achieve precise and fast control. Over-temperature and color mixing often occur, and it is very difficult to print good two-color. Summary of the invention:

[0005] In view of the shortcomings and deficiencies in the prior art, the present invention proposes a thermal print head and a printing method suitable for two-color printing, which can overcome the problem of two-color blurring caused by inaccurate color development temperature in two-color printing.

[0006] The present invention is achieved by the following measures:

[0007] A thermal print head suitable for two-color printing is provided with an insulating substrate, a base glaze layer is provided on the surface of the insulating substrate, electrode wires and a heating resistor are provided on the surfaces of the insulating substrate and the base glaze layer, the heating resistor is composed of more than two heating units, a heating resistor is provided in the heating unit, and any effective printing point corresponds to a heating unit. It is characterized in that more than two heating resistors in the heating resistor are arranged in parallel in two rows along the main printing direction, more than two heating resistors in the same row have the same resistance value, and two heating resistors in different rows have different resistance values, each heating unit is composed of two heating resistors arranged front and back in the secondary printing direction, a control IC is respectively connected to the heating resistor in each heating unit, and control signals of the two heating resistors in any heating unit are sent by two independent Ton control signal output terminals in the control IC.

[0008] In the present invention, the control signal of each heating resistor corresponds to two or more heating resistors arranged in two rows, and the whole is divided into two groups. The two groups of control signals are sent out by two independent Ton control signal output circuits.

[0009] The offset of the two heating resistors in any heating unit in the secondary printing direction is no more than 1 / 3 of the size of a single heating element in the main printing direction, that is, the heating resistors in the first row overlap with the heating resistors in the second row by at least 2 / 3 in the secondary printing direction.

[0010] In the present invention, the number of dots at the control signal output terminal on the control IC is twice the number of effective printing dots on the print head.

[0011] In the present invention, the electrode wire includes a common electrode and an individual electrode. One end of the common electrode is connected to the heating resistor, and the other end is connected to the power supply; one end of the individual electrode is connected to the heating resistor, and the other end is connected to the control IC through the pad on the upper surface of the substrate through a pressure welding wire. The control IC can control the switch of a single heating point according to the printing content. The surface of the individual electrode and the common electrode is provided with a first insulating protective layer, which has good thermal conductivity and is electrically insulating.

[0012] The present invention also proposes a printing method for a thermal print head for two-color printing as described above, characterized in that, under a constant voltage control mode, the control IC makes any two heating resistors in the same row have the same resistance value, while any two heating resistors in different rows have different resistance values, so that the two rows of heating resistors output printing energies with stable differences under a constant voltage, thereby realizing two-color printing and color display. Specifically, when printing different colors, a row of printing data is first divided into two groups according to the color, and the two independent control signal output terminals on the control IC are respectively sent to the corresponding heating resistors in any heating unit. When the printing medium passes through the two rows of heating elements, the two rows of heating elements respectively complete the first color printing and the second color printing of the same area in sequence according to the printing data output by the control IC.

[0013] In the printing method of the thermal print head for two-color printing described in the present invention, when the distance between two rows of heating elements in the secondary printing direction is not equal to an integer multiple of the line spacing of the resolution defined by the print head, corresponding to a row of printing data with two colors to be printed, the printing data is split into two rows, and only one color is retained in each row of printing data, that is, the control data corresponding to the color display bit is 1, and the remaining bits are 0. When the printing medium passes through the two rows of heating elements, when passing through the first row of heating elements, the control IC receives and sends the first color 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 first color of the current row. When the same printing position of the printing medium passes through the second row of heating elements, the control IC receives and sends the second color 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 second color 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 two-color printing of this row is completed. After the entire printed content passes through the two rows of heating elements, the entire two-color printing process is completed.

[0014] In the printing method of the thermal print head for two-color printing described in the present invention, when the distance between two rows of heating resistors in the secondary printing direction is equal to an integer multiple N of the line spacing of the resolution defined by the print head, the printing medium is printed once each time it moves a line distance; when printing the first N lines, the printing data is the data of the line corresponding to the first color, and the remaining bits are filled with 0, wherein the first color corresponds to the color corresponding to the row of heating resistors that first contacts the thermal medium, and when printing N+1 lines begins, the printing data becomes the data of the current corresponding line of the first color, i.e., the N+1 line, and the data of the current corresponding line of the second color, i.e., the 1st line, which are recombined into a new line of data. At this time, the two rows of heating elements work simultaneously, and print the corresponding colors of their own corresponding lines respectively, until the first color completes the printing of the last line, and the second color needs to print N more lines before the printing can be completed. The printing data is the data of the current line of the second color, and the remaining bits are filled with 0. When the printing of the last line of the second color is completed, the entire two-color printing process is completed.

[0015] In the present invention, since the two parallel rows of heating elements each have a Ton control signal, the heating time of the heating elements in the corresponding rows can be independently controlled. When the consumables change, if color 1 prints normally and color 2 is not printing enough, the action time of the Ton signal controlling the operation of the heating element corresponding to color 2 can be extended to increase its temperature so as to achieve the purpose of making color 2 full of color. In the same way, the concentration of color 1 can be adjusted by controlling the time of another Ton signal.

[0016] Compared with the prior art, during the printing process, the thermal print head of the present invention can output two color development temperatures with obvious differences according to different color development temperature requirements, thereby fundamentally solving the blurring and color mixing problems of two-color printing. Description of the drawings:

[0017] Attached Figure 1 It is a schematic diagram of the printing state of the thermal print head in the present invention.

[0018] Attached Figure 2 This is a schematic diagram of the existing thermal printer head heating resistor and electrode wire structure. Figure 3 It is a schematic diagram of the structure of the heating resistor and the electrode wire in the present invention.

[0019] Attached Figure 4 This is a color temperature curve of the heating resistor during two-color printing in the present invention. Figure 5 Attached is a schematic diagram of printing control data grouping in the two-color printing process of the present invention. Figure 6 The present invention is a flow chart for performing two-color printing when the distance between two rows of heating elements is equal to an integral multiple of the line spacing of the printing resolution.

[0020] Attached Figure 7 It is a connection diagram of the control IC and the heating resistor in the embodiment of the present invention.

[0021] Figure numerals: common electrode 1, second row heating element 2, first row heating element 3, individual electrode 4, control IC 5, pressure pad on substrate 6, pressure pad on IC 7, pressure welding wire 8, heating element 9 of ordinary print head, heat dissipation substrate 10, insulating substrate 11, base glaze layer 12, wire layer 13, first insulating protective layer 14, printing medium 15, rubber roller 16. Specific implementation method:

[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0023] Example:

[0024] As attached Figure 1 And attached Figure 3As shown, the print head proposed in this example includes a heat dissipation substrate 10, an insulating substrate 11 is provided on the heat dissipation substrate 10, a full or partial bottom glaze layer 12 is provided on the surface of the insulating substrate 11, 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 control IC5, and the control IC5 can control the switch of a single point according to the printing content. A first insulating protective layer 14 is provided near the heating element on the surface of the individual electrode 2 and the common electrode 1, and the protective layer has good thermal conductivity and is electrically insulated. The above structure is a general structure of a print head;

[0025] The characteristic of this example is that Figure 3 As shown in the figure, the heating point corresponding to each printing point is composed of two heating resistors, and the distribution of the two heating resistors is arranged one after the other in the secondary printing direction, as shown in the attached figure. Figure 7 As shown, two heating resistors share a common electrode and are connected to different control points on the same control IC5. In this example, the number of control points on the control IC5 is twice the number of effective printing points on the print head. The heating elements are arranged in two parallel rows in the main printing direction, and in each row, the resistance values ​​of any two heating resistors are the same, and the resistance values ​​of any two heating resistors in different rows are different. In addition, the Ton signal for controlling the two heating resistors in the same heating unit is also divided into two independent paths (two parallel rows of heating elements each have a Ton control signal, which can independently control the heating time of the heating elements in each corresponding row). This design can make the same control conditions (constant voltage conditions) as Figure 4 The temperatures of the two rows of heating elements are different, and when the color development temperature of the two-color printing consumables changes, the temperature difference between the two rows of heating elements can be adjusted by controlling the action time of each Ton signal to adapt to the different color development temperatures of the consumables;

[0026] In this example, the resistance values ​​of the two rows of heating resistors correspond to the color development temperature of two-color printing, so that one row of heating resistors is fixed to correspond to the color development temperature of one color, and the other row of heating resistors is fixed to correspond to the color development temperature of the second color; the heating unit corresponding to each printing point (composed of two heating resistors located in two rows one in front and one behind) is controlled by the two control signals of the control IC5 to execute no printing or printing of one color;

[0027] When printing in two colors, Figure 5 As shown, firstly, the printing data sent to the control IC5 needs to be processed in groups: Figure 5Take the original image data as an example. The original image data is two oblique lines of different colors with a total of 7 rows of data. 1 represents color 1 and 2 represents color 2. Since each heating point in this example corresponds to two heating resistors and two control bits on the control IC5, the left side of the two bits is set to control the first row of heating elements and the right side is set to control the second row of heating elements. First, expand each point data of the original image to two bits to correspond to the control point bits on the control IC5. The data representing color 1 is on the left side of the two control bits representing a printing point, and the right side is filled with 0. Similarly, color 2 is on the right side, and the left side is filled with zero.

[0028] After expanding the data, the data is divided into two groups according to the two colors. The data of color 1 group corresponds to the original position of color 2 and is replaced by 0. The data of color 2 group is processed in the same way. Finally, the following is obtained: Figure 5 There are two sets of color data, and the first color data in row N is named N -1 , the second color data of the Nth row is named N -2 , then when printing, if Figure 6 A two-color printing control method is introduced. This method is suitable when the distance between two rows of heating elements in the sub-printing direction is equal to twice the resolution line spacing:

[0029] When you start printing, Figure 1 The rubber roller 16 presses the two-color printing medium 15 onto the two rows of heating elements, and then rotates clockwise to drive the printing medium 15 to move forward along the secondary printing direction. When the position of the first line printed on the printing medium 15 passes the first row of heating elements 3, as shown in FIG. Figure 6 As shown, the first row first color 1-1 print data is sent to the heating element via the control IC5. When the second row position of the print medium 15 passes the first row heating element 3, the second row first color 2-1 print data is sent to the heating element via the control IC5. When the third row position of the print medium 15 passes the first row heating element 3, the first row position of the print medium 15 just passes the second row heating element 2. At this time, it is necessary to merge the data corresponding to the third row first color 3-1 and the first row second color 1-2 into a new set of data and send them together to IC5 to control the two rows of heating elements to print at the same time. According to this method, When both rows of heating elements are in contact with the printing target area of ​​the printing medium, the data of the corresponding colors of the corresponding rows of the two rows of heating elements are added and combined to generate new data for printing. When the last row of the printing medium 15 passes the first row of heating elements 3, the next time the printing is performed, when the penultimate row of the printing medium 15, i.e. the 6th row, passes the second row of heating elements 2, the data corresponding to the second color 6-2 of the sixth row is transmitted to IC5 to control the printing of the heating elements. When the 7th row of the printing medium 15 passes the second row of heating elements 2, the data corresponding to the second color 7-2 of the seventh row is transmitted to IC5 to control the printing of the heating elements. This completes the printing. Figure 5 Printing of two colors of oblique lines in Zhongyuan;

[0030] Since the two parallel rows of heating elements each have a Ton control signal, the heating time of the heating elements in the corresponding rows can be controlled independently. When the consumables change, if color 1 prints normally and color 2 is not printing enough, the Ton signal action time of the heating element corresponding to color 2 can be extended to increase its temperature to make color 2 full. In the same way, the concentration of color 1 can be adjusted by controlling the time of another Ton signal.

[0031] Compared with the prior art, during the printing process, the thermal print head of the present invention can output two color development temperatures with obvious differences according to different color development temperature requirements, thereby fundamentally solving the blurring and color mixing problems of two-color printing.

Claims

1. A printing method for a thermal print head suitable for two-color printing, wherein: A thermal print head suitable for two-color printing is provided with an insulating substrate, a base glaze layer is provided on the surface of the insulating substrate, electrode wires and a heating resistor are provided on the surfaces of the insulating substrate and the base glaze layer, the heating resistor is composed of more than two heating units, a heating resistor is provided in the heating unit, and any effective printing point corresponds to a heating unit, characterized in that more than two heating resistors in the heating resistor are arranged in parallel in two rows along the main printing direction, more than two heating resistors in the same row have the same resistance value, and two heating resistors in different rows have different resistance values, each heating unit is composed of two heating resistors arranged front and back in the secondary printing direction, a control IC is respectively connected to the heating resistor in each heating unit, and control signals of the two heating resistors in any heating unit are sent by two independent Ton control signal output circuits in the control IC, The printing method of the thermal print head for two-color printing includes: the control IC is in a constant voltage control mode, through any two heating resistors located in the same row have the same resistance value, and any two heating resistors located in different rows have different resistance values, so that the two rows of heating resistors output printing energy with stable differences under constant voltage, so as to realize two-color printing color display. Specifically, when printing different colors, firstly, a row of printing data is divided into two groups according to the color, and two independent control signal output terminals on the control IC are respectively sent to the corresponding heating resistors in any heating unit. When the printing medium passes through the two rows of heating resistors, the two rows of heating resistors respectively complete the first color printing and the second color printing of the same area in sequence according to the printing data output by the control IC; When the distance between the two rows of heating resistors in the secondary printing direction is not equal to an integer multiple of the line spacing of the print head definition resolution, corresponding to a line of print data with two colors to be printed, the print data is split into two lines, and only one color is retained in each line of print data, that is, the control data corresponding to the color display bit is 1, and the remaining bits are 0. When the print medium passes through the two rows of heating resistors, the control IC receives and sends the first color data of the current line corresponding to the first row of heating resistors when passing through the first row of heating resistors, and the first row of heating resistors completes the printing of the first color of the current line. When the same printing position of the print medium passes through the second row of heating resistors, the control IC receives and sends the second color data of the current line corresponding to the second row of heating resistors, and the second row of heating resistors completes the printing of the second color of the current line. The two rows of heating resistors work alternately. When the same line position on the print medium passes through the two rows of heating resistors in sequence, the two-color printing of this line is completed. After the entire print content passes through the two rows of heating resistors, the entire two-color printing process is completed.

2. A printing method for a thermal print head suitable for two-color printing according to claim 1, characterized in that: In the printing method of the thermal print head for two-color printing, when the distance between the two rows of heating resistors in the secondary printing direction is equal to twice the line spacing of the resolution defined by the print head, the printing medium is printed once each time it moves a line; when printing the first two lines, the printing data is the data of the line corresponding to the first color, and the remaining bits are filled with 0, wherein the first color corresponds to the color corresponding to the row of heating resistors that first contacts the thermal medium; when printing three lines, the printing data becomes the data of the current corresponding line of the first color, i.e., line 3, and the data of the current corresponding line of the second color, i.e., line 1, which are recombined into a new line of data. At this time, the two rows of heating resistors work simultaneously, and print the corresponding colors of their corresponding lines respectively, until the first color completes the printing of the last line, and the second color needs to print 2 more lines before the printing can be completed. The printing data is the data of the current line of the second color, and the remaining bits are filled with 0. When the second color finishes printing the last line, the entire two-color printing process is completed.

3. The printing method of the thermal print head suitable for two-color printing according to claim 1, characterized in that: Since the two parallel rows of heating resistors each have a Ton control signal, the heating time of the heating resistors in the corresponding row can be controlled independently. When the consumables change, if color 1 prints normally and color 2 is not printing enough, the action time of the Ton signal controlling the heating resistor corresponding to color 2 can be extended to increase its temperature to achieve the purpose of making color 2 full of color. In the same way, the concentration of color 1 can be adjusted by controlling the time of another Ton signal.

4. A printing method for a thermal print head suitable for two-color printing according to claim 1, characterized in that: The thermal print head suitable for two-color printing corresponds to more than two heating resistors arranged in two rows, and the overall control signal of each heating resistor is divided into two groups, and the two groups of control signals are sent out by two independent Ton control signal output circuits.

5. A printing method for a thermal print head suitable for two-color printing according to claim 1, characterized in that: In the thermal print head suitable for two-color printing, the offset of the two heating resistors in any heating unit in the secondary printing direction is no more than 1 / 3 of the size of a single heating resistor in the main printing direction, that is, the heating resistors in the first row and the heating resistors in the second row overlap by at least 2 / 3 in the secondary printing direction.

6. A printing method for a thermal print head suitable for two-color printing according to claim 1, characterized in that: The number of dots at the control signal output terminal of the control IC in the thermal print head suitable for two-color printing is twice the number of effective printing dots on the print head.

7. A printing method for a thermal print head suitable for two-color printing according to claim 1, characterized in that: The electrode wires in the thermal print head suitable for two-color printing include a common electrode and an individual electrode. One end of the common electrode is connected to the heating resistor, and the other end is connected to the power supply; one end of the individual electrode is connected to the heating resistor, and the other end is connected to the control IC through the pad on the surface of the substrate through a pressure welding wire. The control IC can control the switch of a single heating point according to the printing content. The surface of the individual electrode and the common electrode is provided with a first insulating protective layer, which has good thermal conductivity and is electrically insulating.

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