Printers and printing programs

Abstract

To provide a printer and a printing program which can realize multicolor printing that makes a color development layer properly develop colors at a low grade and a low cost by accurately controlling energy to be applied to a recording medium.SOLUTION: A printer comprises: a thermal head which has a plurality of heater elements that apply energy to a recording medium Mm having a first color development part 621A that develops a first color when exceeding a first temperature and a second color development part 622A that develops a second color when exceeding a second temperature lower than the first temperature; and a measurement unit which measures power supplied to the plurality of heater elements of the thermal head. The printer periodically supplies power to the plurality heater elements until end timing determined according to the power measured by the measurement unit. When making the first color development part 621A develop the color, the average cycle of supply of the power is the first average cycle. When making the second color development part 622A develop the color, the average cycle of supply of the power is the second average cycle longer than the first average cycle.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a printer and a printing program.

Background Art

[0002] A thermal printer capable of multicolor printing has been proposed. Patent Document 1 discloses an image forming apparatus that performs printing using an image member provided with a plurality of coloring layers having different coloring characteristics. The image forming apparatus repeatedly applies energy to the image member at a predetermined period by a print head. The image forming apparatus controls the time for which energy is applied in each period, and forms an image on the image member by causing each of the plurality of coloring layers to develop color.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When multicolor printing is performed by the above-described method, a high-performance and expensive printer is required to accurately control the energy applied to the recording medium and cause the desired coloring layer to develop color. On the other hand, there is a demand for realizing multicolor printing using an inexpensive printer.

[0005] An object of the present invention is to provide a printer and a printing program that can realize multicolor printing in which the energy applied to a recording medium is accurately controlled to appropriately develop a coloring layer at a low level and at a low cost.

Means for Solving the Problems

[0006] A printer according to a first aspect of the present invention comprises a thermal head equipped with a plurality of heating elements that supply energy to a recording medium having a first color-developing section that develops a first color when the temperature exceeds a first temperature and a second color-developing section that develops a second color when the temperature exceeds a second temperature lower than the first temperature; a measurement unit that measures the power supplied to the plurality of heating elements of the thermal head; and a control unit that controls the periodic supply of the power to the plurality of heating elements, wherein the control unit periodically supplies the power to the plurality of heating elements until an end timing determined according to the power measured by the measurement unit, and when developing the first color-developing section, the average period of the power supply is set to a first average period, and when developing the second color-developing section, the average period of the power supply is set to a second average period which is longer than the first average period.

[0007] In the first embodiment, the printer supplies power to multiple heating elements of the thermal head for coloring the recording medium at different average cycles depending on whether it is coloring the first color-developing area of ​​the recording medium or the second color-developing area of ​​the recording medium. This allows the printer to accurately supply the recording medium with the power and supply time required to color the first color-developing area and the power and supply time required to color the second color-developing area. Therefore, the printer can appropriately color the first and second color-developing areas of the recording medium. Furthermore, by setting the power supply cycle for coloring the second color-developing area to a second cycle that is longer than the first cycle, the printer can appropriately color the first and second color-developing areas of the recording medium with a low-grade and inexpensive configuration.

[0008] In the first embodiment, the recording medium has a first color-developing layer and a second color-developing layer stacked on top of each other, and the first color-developing portion may be included in the first color-developing layer, and the second color-developing portion may be included in the second color-developing layer. In this case, the printer can use a recording medium including the first color-developing layer and the second color-developing layer to appropriately develop the first color-developing portion and the second color-developing portion.

[0009] In the first embodiment, the recording medium further includes a third color-developing layer which includes a third color-developing portion that develops a third color when the temperature exceeds a third temperature that is lower than the first temperature and higher than the second temperature, and when the control unit develops the third color-developing layer, the average period of the power supply may be the same as or longer than the first average period, and shorter than the second average period. In this case, the printer can appropriately develop the third color-developing portion of the third color-developing layer in addition to the first color-developing portion of the first color-developing layer and the second color-developing portion of the second color-developing layer.

[0010] A printer according to a second aspect of the present invention comprises a thermal head equipped with a plurality of heating elements that impart energy to a recording medium, a measuring unit that measures the power supplied to the plurality of heating elements of the thermal head, and a control unit that controls the periodic supply of the power to the plurality of heating elements, wherein the control unit acquires the type of the recording medium, periodically supplies the power to the plurality of heating elements until an end timing determined according to the power measured by the measuring unit, and switches the average period of the power supply according to the acquired type.

[0011] The printer according to the second embodiment switches the cycle of supplying power to the thermal head to produce color on the recording medium according to the type of recording medium. This allows the printer to specify and accurately supply the power and supply time required to produce color on the recording medium for each type of recording medium. Therefore, the printer can produce color on the recording medium appropriately.

[0012] A printing program according to a third aspect of the present invention is characterized in that a computer that controls the periodic supply of power to a plurality of heating elements of a thermal head that provides energy to a recording medium having a first color developing section that develops a first color when the temperature exceeds a first temperature and a second color developing section that develops a second color when the temperature exceeds a second temperature lower than the first temperature, causes the computer to perform a step of periodically supplying power to the plurality of heating elements until an end timing determined according to the power measured by a measuring unit that measures the power supplied to the plurality of heating elements, wherein when the first color developing section develops color, the average period of the power supply is set to a first average period, and when the second color developing section develops color, the average period of the power supply is set to a second average period which is longer than the first average period. According to the third aspect, the same effects as the first aspect are achieved.

[0013] A printing program according to a fourth aspect of the present invention causes a computer that controls the periodic supply of power to a plurality of heating elements of a thermal head equipped with a plurality of heating elements that impart energy to a recording medium to perform the following steps: acquire the type of the recording medium; periodically supply the power to the plurality of heating elements until an end timing determined according to the power measured by a measuring unit that measures the power supplied to the plurality of heating elements; and switch the average period of the power supply according to the acquired type. The fourth aspect provides the same effects as the second aspect. [Brief explanation of the drawing]

[0014] [Figure 1] (A) is a perspective view of printer 1 with cover 3 closed, and (B) is a perspective view of printer 1 with cover 3 open. [Figure 2] This is a plan view of the cassette mounting section 8 into which the cassette 6 is installed, with the bottom surface of the cassette mounting section 8 omitted from the illustration. [Figure 3] This is a perspective view of thermal tape M. [Figure 4] This is a block diagram showing the electrical configuration of printer 1. [Figure 5] This graph shows the time-dependent changes in the signal level output to the driver 73 and the actual power supplied when the first color-generating unit 621A is activated. [Figure 6] This graph shows the time-dependent changes in the signal level output to the driver 73 and the power detected by the measurement unit 74 when the third color-emitting unit 623A is activated. [Figure 7] This graph shows the time-dependent changes in the signal level output to the driver 73 and the power detected by the measurement unit 74 when the second color-generating unit 622A is activated. [Figure 8] This is a flowchart of the main process. [Figure 9] This is a flowchart of the main process, a continuation of Figure 8. [Modes for carrying out the invention]

[0015] One embodiment of the present invention will be described in order with reference to the drawings. The drawings are used to explain the technical features that the present invention may adopt, and the configuration of the device described is not intended to be the sole limiting factor, but is merely an illustrative example. In the description of this embodiment, the lower left, upper right, lower right, upper left, upper, and lower sides of Figure 1 will be referred to as the left, right, front, rear, upper, and lower sides of the printer 1, respectively.

[0016] <Overview of Printer 1> Printer 1 will be described with reference to Figures 1 and 2. Printer 1 is a thermal and thermal transfer tape printing device. As an example, printer 1 is equipped with a cassette 6 containing a thermal tape M as a recording medium. Printer 1 performs printing by heating the thermal tape M unwound from cassette 6 with a thermal head 15, which will be described later.

[0017] As shown in FIGS. 1(A) and 1(B), the printer 1 includes a housing 2, a cover 3, a display unit 4, and an operation unit 5. The housing 2 has a substantially rectangular parallelepiped shape. A discharge slit 10 is formed on the left side surface of the housing 2. The discharge slit 10 is an opening extending in the vertical direction and discharges the printed thermal tape M to the outside of the housing 2. The cover 3 is supported at the rear end portion of the housing 2 so as to be rotatable about an axis extending in the left-right direction. FIG. 1(A) shows a state where the cover 3 is closed with respect to the housing 2, and FIG. 1(B) shows a state where the cover 3 is opened with respect to the housing 2. The cover 3 is opened and closed, for example, when replacing the cassette 6. In the following description, the configuration of each member will be described based on the state where the cover 3 is closed with respect to the housing 2.

[0018] As shown in FIG. 1(A), the display unit 4 is provided on the upper surface of the cover 3. The display unit 4 is, for example, a liquid crystal display and can display various information. The operation unit 5 is disposed in front of the cover 3 and at the front portion of the upper surface of the housing 2. The operation unit 5 is operated when inputting various instructions to the printer 1.

[0019] As shown in FIGS. 1(B) and 2, the printer 1 includes a cassette mounting portion 8, a head holder 16, a thermal head 15, a platen holder 13, a platen roller 11, a conveyance roller 12, a motor 36, and a cutting mechanism 17 in a space surrounded by the housing 2 and the cover 3.

[0020] The cassette mounting portion 8 is a recessed portion that is recessed downward and capable of mounting the cassette 6. The head holder 16 is a metal plate-like member provided at the front portion of the cassette mounting portion 8. The head holder 16 mounts the thermal head 15 on the front surface. The thermal head 15 includes a plurality of heating elements.

[0021] The platen holder 13 is arm-shaped and located in front of the head holder 16. The right end of the platen holder 13 is pivotally supported around a vertically extending shaft 14. The platen roller 11 and the transport roller 12 are pivotally supported at the left end of the platen holder 13 around a vertically extending shaft. The platen roller 11 faces the thermal head 15 and can move toward and away from the thermal head 15. The transport roller 12 is located to the left of the platen roller 11. The transport roller 12 can move toward and away from a transport roller (not shown) provided on the cassette 6. The platen holder 13 swings between a standby position and a printing position in conjunction with the opening and closing of the cover 3. The printing position is when the platen holder 13 is close to the cassette mounting section 8.

[0022] When cover 3 is opened, platen holder 13 moves from the printing position to the standby position. The standby position is when platen holder 13 is separated from cassette mounting section 8. When platen holder 13 is in the standby position, the user can attach and detach cassette 6 to and from cassette mounting section 8. When cover 3 is closed, platen holder 13 swings from the standby position to the printing position. When cassette 6 is mounted in cassette mounting section 8, platen roller 11 presses thermal tape M against thermal head 15. Transport roller 12 holds the thermal tape M between itself and the transport roller of cassette 6.

[0023] Motor 36 is a stepping motor. The rotational driving force of motor 36 is transmitted to the platen roller 11 and the conveyor roller 12. When motor 36 is driven with the cassette 6 mounted in the cassette mounting section 8, the platen roller 11 and the conveyor roller 12 rotate in a counterclockwise direction in a plan view.

[0024] The cutting mechanism 17 is located to the left of the cassette mounting section 8 and to the right of the discharge slit 10 (see Figure 1(B)). The cutting mechanism 17 cuts the thermal tape M discharged from the cassette 6. The cutting mechanism 17 has a metal fixed blade 18 and a movable blade 19. The movable blade 19 is positioned opposite the fixed blade 18 and is movable relative to the fixed blade 18.

[0025] <Thermal Tape M> The thermal tape M is housed within the casing 60 of the cassette 6. The thermal tape M is a long-length medium composed of multiple layers. There are two types of thermal tape M that can be printed on by the printer 1: thermal tape Mm for multi-color printing and thermal tape Ms for single-color printing.

[0026] As shown in Figure 3, the thermal tape Mm for multi-color printing has a base material 61, a plurality of color-developing layers 62, a plurality of heat-shielding layers 63, and an overcoat layer 64. The plurality of color-developing layers 62 include a first color-developing layer 621, a third color-developing layer 623, and a second color-developing layer 622. The plurality of heat-shielding layers 63 include a first heat-shielding layer 631 and a second heat-shielding layer 632.

[0027] The overcoat layer 64, the first color development layer 621, the first heat shielding layer 631, the third color development layer 623, the second heat shielding layer 632, the second color development layer 622, and the substrate 61 are laminated in this order in the thickness direction of the thermal tape Mm. The multiple color development layers 62 and the multiple heat shielding layers 63 are transparent. When printing by the printer 1, the platen roller 11 contacts the substrate 61 side surface of the thermal tape Mm, and the thermal head 15 contacts the overcoat layer 64 side surface of the thermal tape Mm.

[0028] The base material 61 is a resin film. Each of the multiple color-developing layers 62 contains a color-developing portion that changes color when the temperature rises. The first heat-shielding layer 631 suppresses heat conduction between the adjacent first color-developing layer 621 and the third color-developing layer 623. The second heat-shielding layer 632 suppresses heat conduction between the adjacent third color-developing layer 623 and the second color-developing layer 622. The overcoat layer 64 protects the multiple color-developing layers 62.

[0029] The first color-developing layer 621 includes a first color-developing section 621A. When the transparency of the first color-developing section 621A exceeds a predetermined first temperature T1, it decreases and develops a first color. For example, the first color is yellow. The third color-developing layer 623 includes a third color-developing section 623A. When the transparency of the third color-developing section 623A exceeds a predetermined third temperature T3, it decreases and develops a third color. For example, the third color is magenta. The second color-developing layer 622 includes a second color-developing section 622A. When the transparency of the second color-developing section 622A exceeds a predetermined second temperature T2, it decreases and develops a second color. For example, the second color is cyan. The third temperature T3 is lower than the first temperature T1 (T1>T3). The second temperature T2 is lower than the third temperature T3 (T3>T2).

[0030] The thermal tape Ms has a structure obtained by removing the third color-developing layer 623, the second color-developing layer 622, and the multiple heat-shielding layers 63 from the thermal tape Mm. The first color-developing portion 621A included in the first color-developing layer 621 of the thermal tape Ms loses transparency and develops a first color when the temperature exceeds the first temperature T1.

[0031] <Overview of Printing Operations> Printer 1 feeds out thermal tape M from cassette 6. As the fed-out thermal tape M passes between the thermal head 15 and the platen roller 11, the platen roller 11 presses it against the thermal head 15. In this state, Printer 1 applies voltage to multiple heating elements of the thermal head 15. Power is supplied to the multiple heating elements in response to the current flowing due to the applied voltage. The multiple heating elements generate heat as power is supplied. The heated multiple heating elements transfer energy to the thermal tape M from the overcoat layer 64 side. As a result, the color-developing parts of the thermal tape M are heated and develop color, and an image is printed on the thermal tape M.

[0032] The printed thermal tape M is transported by the platen roller 11 and transport roller 12, which are rotated by the motor 36, and discharged to the outside of the printer 1 through the discharge slit 10.

[0033] <Electrical Configuration> Referring to Figure 4, the electrical configuration of printer 1 will be explained. Printer 1 is equipped with a CPU 71 that controls the entire printer. The CPU 71 is electrically connected to the memory unit 72, display unit 4, operation unit 5, motor 36, driver 73, and measurement unit 74. The memory unit 72 stores the program executed by the CPU 71, print data, and setting data. The display unit 4 displays various information according to the signals output from the CPU 71. Signals indicating input operations performed on the operation unit 5 are output from the operation unit 5 to the CPU 71. By detecting the signals output from the operation unit 5, the CPU 71 can detect input operations performed on the operation unit 5.

[0034] The motor 36 is driven in response to a signal output from the CPU 71, rotating the platen roller 11 and the transport roller 12. The driver 73 supplies power to the multiple heating elements of the thermal head 15 in response to a signal output from the CPU 71. The measurement unit 74 measures the power supplied to the multiple heating elements of the thermal head 15 and outputs a signal indicating the measured power to the CPU 71. Based on the signal output from the measurement unit 74, the CPU 71 can detect the power actually supplied to the multiple heating elements of the thermal head 15.

[0035] <Details of printing operation> The details of the printing operation will be explained using the case of printing on thermal tape Mm as an example. During printing, the CPU 71 periodically supplies power to the multiple heating elements of the thermal head 15. Figures 5A, 6A, and 7A show the change in the signal level output by the CPU 71 to the driver 73 over time. When the signal output from the CPU 71 is at a low level, the driver 73 supplies power to the multiple heating elements of the thermal head 15, and when the signal output from the CPU 71 is at a high level, it stops supplying power to the multiple heating elements of the thermal head 15. At the same time, the CPU 71 detects the power P actually supplied to the multiple heating elements of the thermal head 15 based on the signal output from the measurement unit 74.

[0036] Figures 5B, 6B, and 7B show the time-dependent change in the power P actually supplied to the heating element when the thermal head 15 prints one dot, respectively. In Figures 5B, 6B, and 7B, power P is applied periodically. Hereinafter, the time during which power P is supplied in Figure 5B will be referred to as "first time t1". In Figure 6B, the time during which power P is supplied will be referred to as "third time t3". In Figure 7B, the time during which power P is applied will be referred to as "second time t2". Note that in Figures 5, 6, and 7, the first time t1, third time t3, and second time t2 are shown to be constant in each period, but in reality, the first time t1, third time t3, and second time t2 are variable according to the measured power. The first time t1, third time t3, and second time t2 are collectively referred to as "supply time t". The rising and falling edges of the waveforms shown in Figures 5B, 6B, and 7B are distorted due to the filter components of the circuit system included in the thermal head 15.

[0037] In Figure 5B, the time-averaged power P required to produce color in the first color-producing section 621A is shown as "First Target Power Pt1". In Figure 6B, the time-averaged power P required to produce color in the third color-producing section 623A is shown as "Third Target Power Pt3". In Figure 7B, the time-averaged power P required to produce color in the second color-producing section 622A is shown as "Second Target Power Pt2". The first target power Pt1, third target power Pt3, and second target power Pt2 are collectively referred to as "Target Power Pt".

[0038] The CPU 71 calculates the amount of power supplied to the multiple heating elements of the thermal head 15 based on the detected power P and the supply time t during which power was supplied. The CPU 71 continues to supply power periodically while changing the supply time t until the cumulative amount of calculated power satisfies the condition. When the cumulative amount of power supplied to the multiple heating elements satisfies the condition, the printer 1 stops the periodic power supply to the multiple heating elements.

[0039] The timing at which the CPU 71 stops the periodic power supply (hereinafter referred to as the "end timing") varies depending on the color to which the thermal tape Mm is to be colored. When coloring the first coloring portion 621A of the thermal tape Mm, the timing when the cumulative amount of power supplied to the plurality of heating elements reaches the first power amount E1 or more is the end timing. When coloring the third coloring portion 623A of the thermal tape Mm, the timing when the cumulative amount of power supplied to the plurality of heating elements reaches the third power amount E3 or more is the end timing. When coloring the second coloring portion 622A of the thermal tape Mm, the timing when the cumulative amount of power supplied to the plurality of heating elements reaches the second power amount E2 or more is the end timing. Hereinafter, the first power amount E1, the third power amount E3, and the second power amount E2 are collectively referred to as the "threshold power amount E".

[0040] Also, the average of the periods for supplying power to the plurality of heating elements of the thermal head 15 (hereinafter referred to as the "average period") varies depending on the color to which the thermal tape Mm is to be colored. In FIGS. 5, 6, and 7, as an example, the case where the period does not change over time is shown. Therefore, each period in FIGS. 5, 6, and 7 coincides with the average period obtained by averaging a plurality of repeated periods.

[0041] As shown in FIG. 5, when coloring the first coloring portion 621A of the thermal tape Mm, all the power supply periods are the first period C1. As shown in FIG. 6, when coloring the third coloring portion 623A of the thermal tape Mm, all the power supply periods are the third period C3. As shown in FIG. 7, when coloring the second coloring portion 622A of the thermal tape Mm, all the power supply periods are the second period C2. The first period C1 and the third period C3 are the same (C1 = C3). The second period C2 is longer than the first period C1 and the third period C3 (C1 < C2, C3 < C2). Note that the first period C1 and the third period C3 may be different. For example, the third period C3 may be longer than the first period C1 (C1 < C3). Hereinafter, the first period C1, the third period C3, and the second period C2 are collectively referred to as the "supply period C".

[0042] The ratio of the first hour t1 to the first period C1 (t1 / C1) is called the first ratio. The ratio of the third hour t3 to the third period C3 (t3 / C3) is called the third ratio. The ratio of the second hour t2 to the second period C2 (t2 / C2) is called the second ratio. The first ratio t1 / C1 is greater than the third ratio t3 / C3 (t1 / C1 > t3 / C3). The third ratio t3 / C3 is greater than the second ratio t2 / C2 (t3 / C3 > t2 / C2).

[0043] Furthermore, the shorter the power supply cycle of the thermal head 15 to the multiple heating elements, the more precisely the time during which power is supplied to the multiple heating elements can be controlled. On the other hand, the longer the power supply cycle of the thermal head 15 to the multiple heating elements, the less the effect of the power saturation in the power actually supplied to the multiple heating elements can be reduced, thus enabling more precise control of the power supplied to the multiple heating elements.

[0044] Furthermore, the thickness of each of the multiple color-developing layers 62 of the thermal tape Mm, as well as the material of each color-developing part, differ depending on the type of thermal tape Mm. Therefore, if the type of thermal tape Mm differs, the target power Pt, threshold power amount E, and supply cycle C corresponding to each color-developing part will also differ.

[0045] Note that the printing operation on thermal tape Ms for single-color printing is the same as when the first color-developing section 621A of thermal tape Mm is developed, so the explanation is omitted. Also, in the case of thermal tape Ms, the target power Pt, threshold power amount E, and supply cycle C corresponding to the first color-developing section 621A will differ depending on the type.

[0046] <Main Processing> Referring to Figure 8, the main processing will be explained. When the CPU 71 detects an input operation to start printing via the operation unit 5, it starts by reading and executing a program stored in the storage unit 72.

[0047] The CPU 71 detects the type of cassette 6 installed in the cassette mounting section 8, thereby identifying the type of thermal tape M contained in the cassette 6 (S11). If the CPU 71 identifies the type of thermal tape Mm for multi-color printing (S13: YES), the process proceeds to S15. The following will provide a detailed explanation using the case where the type of thermal tape Mm shown in Figure 3 is identified as an example.

[0048] The CPU 71 reads and obtains setting data from the storage unit 72 for activating the first color-emitting unit 621A, the third color-emitting unit 623A, and the second color-emitting unit 622A, based on the identified type (S15). The setting data includes a first target power Pt1, a first energy quantity E1, and a first period C1 for activating the first color-emitting unit 621A; a third target power Pt3, a third energy quantity E3, and a third period C3 for activating the third color-emitting unit 623A; and a second target power Pt2, a second energy quantity E2, and a second period C2 for activating the second color-emitting unit 622A.

[0049] The CPU 71 drives the motor 36 to start the rotation of the platen roller 11 and the transport roller 12. This causes the CPU 71 to start transporting the thermal tape Mm that has been unwound from the cassette 6 (S17). Based on the print data stored in the memory unit 72, the CPU 71 acquires information on which color the thermal tape Mm should be colored (S19). The CPU 71 selects a color-developing unit from among the first color-developing unit 621A, the third color-developing unit 623A, and the second color-developing unit 622A that corresponds to the acquired color. From the setting data acquired in S15, the CPU 71 acquires the target power Pt, threshold power amount E, and supply cycle C corresponding to the selected color-developing unit (S21).

[0050] The CPU 71 detects the actual power P supplied to the multiple heating elements of the thermal head 15 based on the signal output from the measurement unit 74 (S23).

[0051] The CPU 71 determines a new supply time t based on the detected power P, the supply cycle C, and the target power Pt acquired in S19. Specifically, when P > Pt, the CPU 71 determines a new supply time t such that the relationship P×(t / C) = Pt is satisfied. On the other hand, when P < Pt, the CPU 71 determines a new supply time t such that t = C. The CPU 71 controls the driver 73 so that power is supplied to the plurality of heating elements of the thermal head 15 during the determined supply time t. The driver 73 supplies power to the plurality of heating elements of the thermal head 15 for the supply time t (S25). The CPU 71 calculates the amount of power supplied to the plurality of heating elements based on the power P detected in S23 and the supply time t. Further, the CPU 71 calculates the cumulative amount of power supplied to the plurality of heating elements in order to develop the thermal tape Mm in the color determined in S19 (S27).

[0052] The CPU 71 determines whether the elapsed time since power was supplied to the plurality of heating elements of the thermal head 15 matches the supply cycle C (S29). If the elapsed time since power was supplied does not match the supply cycle C (S29: NO), the CPU 71 returns the process to S29. If the elapsed time since power was supplied matches the supply cycle C (S29: YES), the CPU 71 advances the process to S31.

[0053] The CPU 71 determines whether it is the end timing of power supply to the plurality of heating elements of the thermal head 15 (S31). When the cumulative amount of the calculated power amount is smaller than the threshold power amount E, the CPU 71 determines that it is not the end timing (S31: NO). In this case, the CPU 71 returns the process to S23. The CPU waits until the elapsed time since the power supply to the plurality of heating elements of the thermal head 15 ends matches the supply cycle C (S23). When the elapsed time matches the supply cycle C, the CPU repeats the processes of S25, S27, S29, and S31. Thereby, the power supply to the plurality of heating elements of the thermal head 15 is repeated at the supply cycle C.

[0054] On the other hand, the CPU 71 determines that it is time to terminate if the cumulative amount of calculated power exceeds the threshold power amount E (S31: YES). The CPU 71 determines whether all printing based on the print data has been completed (S33). If the CPU 71 determines that not all printing has been completed (S33: NO), it returns to processing S19. Based on the print data stored in the memory unit 72, the CPU 71 determines which color to use to develop the thermal tape Mm next (S19). The CPU 71 repeats processing S21 to S33 to develop the thermal tape Mm in the determined color. If the CPU 71 determines that all printing has been completed (S33: YES), it terminates the main processing.

[0055] On the other hand, if the CPU 71 identifies the type of thermal tape Ms for single-color printing in S11 (S13: NO), it proceeds to process S55 (see Figure 9). The processes in S55, S57, S63, S65, S67, S69, S71, and S73 shown in Figure 9 are the same as the processes in S15, S17, S23, S25, S27, S29, S31, and S33 (see Figure 8) when the type of thermal tape Mm for multi-color printing is identified. In other words, the process when the type of thermal tape Ms is identified differs from the case when the type of thermal tape Mm is identified in that the determination of which color the thermal tape M should be colored (S19) and the acquisition of setting parameters (target power Pt, threshold power amount E, and supply cycle C) for coloring the colored part corresponding to the determined color (S21) are not performed.

[0056] The CPU 71 reads and obtains setting data from the storage unit 72 to colorize the first color-developing section 621A of the thermal tape Ms based on the identified type (S55). The setting data includes the first target power Pt1, the first energy quantity E1, and the first cycle C1. Of these, at least the first cycle C1 will differ depending on the identified type.

[0057] The processes of S57, S63, S65, S67, S69, S71, and S73 are the same as the processes of S17, S23, S25, S27, S29, S31, and S33 (see FIG. 8), so the description thereof will be omitted. When the CPU 71 determines that all printing has ended (S73: YES), it ends the main process.

[0058] <Operations and Effects of the Present Embodiment> The printer 1 makes the supply cycle C for supplying power to the plurality of heating elements of the thermal head 15 for causing the thermal tape Mm to develop color different between the case of causing the first color developing portion 621A to develop color (first cycle C1) and the case of causing the second color developing portion 622A to develop color (second cycle C2). Thereby, the printer 1 can accurately apply to the thermal tape Mm the power and supply time required for causing the first color developing portion 621A and the second color developing portion 622A to develop color. Therefore, the printer 1 can appropriately cause the first color developing portion 621A and the second color developing portion 622A of the thermal tape Mm to develop color.

[0059] Specifically, when the printer 1 applies high power to the thermal tape Mm in a relatively short time to cause the first color developing portion 621A to develop color, the supply cycle C is set to the first cycle C1 shorter than the second cycle C2 (C1 < C2). Also, the first ratio t1 / C1 is made larger than the second ratio t2 / C2 (t1 / C1 > t2 / C2). Thereby, when causing the first color developing portion 621A to develop color, the printer 1 can precisely control the supply time for supplying power to the thermal tape Mm. Also, the printer 1 can reduce the influence of the power residue actually supplied to the plurality of heating elements of the thermal head 15 by making the second cycle C2 for causing the second color developing portion 622A to develop color relatively long. For this reason, when causing the second color developing portion 622A to develop color, the printer 1 can precisely control the power supplied to the thermal tape Mm.

[0060] As described above, since the printer 1 can precisely control the power and supply time according to the color developing portion to be developed, multicolor printing can be realized with a lower-class and inexpensive configuration.

[0061] Furthermore, the printer sets the first cycle C1 for developing color in the first color-developing unit 621A and the third cycle C3 for developing color in the third color-developing unit 623A to be the same, or makes the third cycle C3 longer than the first cycle C1, while making the first ratio t1 / C1 larger than the third ratio t3 / C3 (t1 / C1 > t3 / C3). As a result, the printer 1 can appropriately develop color in the third color-developing unit 623A in addition to the first color-developing unit 621A and the second color-developing unit 622A.

[0062] The thermal tape Mm is formed by laminating a first color-developing layer 621 including a first color-developing section 621A, a third color-developing layer 623 including a third color-developing section 623A, and a second color-developing layer 622 including a second color-developing section 622A. In this case, temperature control in the thickness direction of the thermal tape Mm is required, making it difficult to properly develop the color-developing sections of each layer. However, the printer 1 can easily achieve control to properly develop the color of each color-developing layer of the thermal tape M by performing the above processing.

[0063] Printer 1 switches the power supply cycle C, which supplies power to multiple heating elements of the thermal head 15 in order to color at least one color-developing area on the thermal tapes Mm and Ms, according to the type of thermal tape Mm and Ms. This allows Printer 1 to precisely specify and supply the power and supply time required to color the color-developing areas on the thermal tapes Mm and Ms for each type of thermal tape Mm and Ms. Therefore, Printer 1 can properly color the thermal tapes Mm and Ms.

[0064] <Variation> The present invention is not limited to the above embodiments, and various modifications are possible. The measurement unit 74 of the printer 1 may measure the current flowing through the multiple heating elements of the thermal head 15 and output the measurement result to the CPU 71. The measurement unit 74 may also measure the voltage applied to the multiple heating elements of the thermal head 15 and output the measurement result to the CPU 71.

[0065] Cassette 6 may further include a transparent film. Printer 1 may attach the transparent film to the thermal tapes Mm and Ms printed by the thermal head 15 and then discharge them through the discharge slit 10. The thermal tape Mm does not have to have multiple heat-shielding layers 63. In this case, the first color-developing layer 621 and the third color-developing layer 623 may be in direct contact at their boundary, and the third color-developing layer 623 and the second color-developing layer 622 may be in direct contact at their boundary. The color-developing layers of the thermal tape Mm are not limited to three layers, but may be four or more layers. Also, the thermal tape Mm may have only a first color-developing layer 621 including a first color-developing part 621A, and a second color-developing layer 622 including a second color-developing part 622A, and may not have a third color-developing layer 623 including a third color-developing part 623A.

[0066] The thermal tape Mm does not necessarily have a first color-developing layer 621, a third color-developing layer 623, and a second color-developing layer 622. For example, the first color-developing portion 621A, the third color-developing portion 623A, and the second color-developing portion 622A may be dispersed in a dispersion medium coated on the substrate 61.

[0067] The target power Pt and threshold power E may be the same regardless of the type of thermal tape (Mm or Ms).

[0068] The printer 1 may vary the power supply cycle over time when coloring the first color-developing section 621A. For example, the printer 1 may repeatedly supply power to multiple heating elements of the thermal head 15 in different first cycles C1(1), C1(2), C1(3), C1(4), C1(5)... The first average cycle, which is the average of the first cycles C1(1), C1(2), C1(3), C1(4), C1(5)..., coincides with the first cycle C1 in the above embodiment. Therefore, the first average cycle is shorter than the second cycle C2 for coloring the second color-developing section 622A. In this case, the printer 1 can appropriately supply the amount of power necessary to color the first color-developing section 621A to the thermal tape Mm.

[0069] The printer 1 may vary the power supply cycle over time when coloring the third color-developing section 623A. For example, the printer 1 may repeatedly supply power to multiple heating elements of the thermal head 15 in different third cycles C3(1), C3(2), C3(3), C3(4), C3(5)... The third average cycle, which is the average of the third cycles C3(1), C3(2), C3(3), C3(4), C3(5)..., coincides with the third cycle C3 in the above embodiment. In this case, the printer 1 can appropriately supply the amount of power necessary to color the third color-developing section 623A to the thermal tape Mm.

[0070] The printer 1 may vary the power supply cycle over time when coloring the second color-developing section 622A. For example, the printer 1 may repeatedly supply power to multiple heating elements of the thermal head 15 in different second cycles C2(1), C2(2), C2(3), C2(4), C2(5)... The second average cycle, which is the average of the second cycles C2(1), C2(2), C2(3), C2(4), C2(5)..., coincides with the second cycle C2 in the above embodiment. Therefore, the second average cycle is longer than the first cycle C1 for coloring the first color-developing section 621A. In this case, the printer 1 can appropriately supply the amount of power necessary to color the second color-developing section 622A to the thermal tape Mm.

[0071] Furthermore, the printer 1 may repeatedly supply power to multiple heating elements of the thermal head 15 in the first cycle C1(1), C1(2), C1(3), C1(4), C1(5)... to color the first color-developing section 621A, repeatedly supply power to multiple heating elements of the thermal head 15 in the second cycle C2(1), C2(2), C2(3), C2(4), C2(5)... to color the second color-developing section 622A, and repeatedly supply power to multiple heating elements of the thermal head 15 in the third cycle C3(1), C3(2), C3(3), C3(4), C3(5)... to color the third color-developing section 623A. In this case, the first mean cycle is shorter than the second mean cycle. Note that the first mean cycle and the third mean cycle may be the same, or the third mean cycle may be longer than the first mean cycle.

[0072] Furthermore, in the above configuration, the printer 1 may keep the supply cycle C constant while the number of times power is supplied to the multiple heating elements of the thermal head 15 is less than a predetermined number of times, and may change the supply cycle C after the number of times power is supplied to the multiple heating elements of the thermal head 15 exceeds the predetermined number of times.

[0073] <Other> Thermal tapes Mm and Ms are examples of the "recording media" of the present invention. [Explanation of Symbols]

[0074] 1: Printer 15: Thermal head 71: CPU 74: Measurement Unit 621: First color layer 621A: First color development section 622: Second color layer 622A: Second color development section 623: Third color-developing layer 623A: Third color-emitting section

Claims

1. A thermal head equipped with multiple heating elements that apply energy to a recording medium having a first color-developing section that develops a first color when the temperature exceeds a first temperature, and a second color-developing section that develops a second color when the temperature exceeds a second temperature lower than the first temperature, A measuring unit for measuring the power supplied to the plurality of heating elements of the thermal head, A control unit that controls the periodic supply of power to the plurality of heating elements, Equipped with, The control unit, The power is periodically supplied to the plurality of heating elements until the termination timing determined according to the power measured by the measurement unit. When the first color-generating section is made to produce color, the average period of the power supply is set to the first average period. When the second color-generating section is activated, the average period of the power supply is set to a second average period that is longer than the first average period. A printer characterized by the following features.

2. The printer according to claim 1, wherein the recording medium has a first color-developing layer and a second color-developing layer stacked on top of each other, the first color-developing portion is included in the first color-developing layer, and the second color-developing portion is included in the second color-developing layer.

3. The aforementioned recording medium is The material further includes a third color-developing layer which includes a third color-developing portion that develops a third color when the temperature exceeds a third temperature that is lower than the first temperature and higher than the second temperature. The control unit, When the third color-developing layer is colored, the average period of the power supply is set to a third average period that is the same as or longer than the first average period, and shorter than the second average period. The printer according to feature 2.

4. A thermal head equipped with multiple heating elements that impart energy to the recording medium, A measuring unit for measuring the power supplied to the plurality of heating elements of the thermal head, A control unit that controls the periodic supply of power to the plurality of heating elements, Equipped with, The control unit, The type of the recording medium is obtained, The power is periodically supplied to the plurality of heating elements until the termination timing determined according to the power measured by the measurement unit. Depending on the acquired type, the average period of power supply is switched. A printer characterized by the following features.

5. A computer that controls the periodic supply of power to a plurality of heating elements of a thermal head, which has a first color-developing section that develops a first color when the temperature exceeds a first temperature and a second color-developing section that develops a second color when the temperature exceeds a second temperature lower than the first temperature, The step of periodically supplying the power to the plurality of heating elements is performed until a termination timing determined according to the power measured by a measuring unit that measures the power supplied to the plurality of heating elements, When the first color-generating section is made to produce color, the average period of the power supply is set to the first average period. A printing program characterized in that, when the second color-developing section is colored, the average period of the power supply is set to a second average period that is longer than the first average period.

6. A computer that controls the periodic supply of power to a plurality of heating elements of a thermal head, which is equipped with a plurality of heating elements that impart energy to a recording medium, A step of obtaining the type of the recording medium, The steps include: periodically supplying the power to the plurality of heating elements until an end timing determined according to the power measured by a measuring unit that measures the power supplied to the plurality of heating elements; The steps include switching the average period of power supply according to the acquired type and A printing program characterized by causing the execution of a specific action.

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