JP2024030295A - Thermal printer, printing method and program - Google Patents

Abstract

An object of the present invention is to increase the linearity of printing density with respect to the number of gradations in multi-gradation printing.
[Solution] When printing each dot, the thermal printer prints each dot in sub-dots 31 so that the number of sub-dots lined up in the main scanning direction Y is equal to the number of sub-dots lined up in the sub-scanning direction X. The gradation is expressed by the area gradation method divided into 34 areas, and the gradation is expressed by the time division method when printing each of the sub-dots 31 to 34. Thermal printers adjust dot gradations so that the height relationship of assigned gradations between subdots lined up in the sub-scanning direction While the general representation in tone representation is assigned to the area gradation method, the detailed representation in dot gradation representation (gradation representation of sub-dots) is assigned to the time division method.
[Selection diagram] Figure 8

Description

The present invention relates to a thermal printer, a printing method, and a program.

2. Description of the Related Art Conventionally, thermal printers have been known that print by heating ink from an ink ribbon or the like and thermally transferring it onto a tape. As this thermal printer, one that prints with multiple gradations of print density is known.

For example, for multiple pixels of image data, each pixel is configured with a diamond-shaped matrix of four dots, and a plurality of time-divided pulses with a constant application time are applied to the thermal head in correspondence with each dot. 2. Description of the Related Art A tape printing device is known as a thermal printer that prints an image on a tape in multiple gradation densities by heating (see Patent Document 1).

Japanese Patent Application Publication No. 11-91152

In printing multiple gradations like the tape printing device described in Patent Document 1, there is a demand for increasing the linearity of print density with respect to gradations.

An object of the present invention is to increase the linearity of printing density with respect to gradation in printing of multiple gradations.

In order to solve the above problems, a thermal printer of the present invention is a thermal printer that has a heating element and prints on a printing medium by energizing the heating element, and when printing each dot. The dots are expressed in gradation using an area gradation method in which each of the dots is divided into a plurality of subdots so that the number of subdots lined up in the main scanning direction is equal to the number of subdots lined up in the subscanning direction, and The controller includes a control unit that performs gradation expression using a time-sharing method that controls the energization time to the heating element in a time-sharing manner when printing each of a plurality of sub-dots, and the control unit controls the sub-dots arranged in the sub-scanning direction. The broad frame representation in the gradation representation is performed using the area gradation method so that the height relationship of assigned gradations between dots is different from the height relationship of assigned gradations between sub-dots adjacent in the main scanning direction. The detailed representation in the gradation representation is assigned to the time division method.

According to the present invention, it is possible to increase the linearity of printing density with respect to gradations in printing of multiple gradations.

1 is an external perspective view showing a thermal printer according to a first embodiment of the present invention. FIG. FIG. 1 is a block diagram showing a printing system. FIG. 2 is a block diagram showing the functional configuration of a PC. FIG. 2 is a block diagram showing the functional configuration of a thermal printer. FIG. 6 is a diagram showing a print image corresponding to an increase in the energization time for one dot. 3 is a flowchart illustrating first print instruction processing. FIG. 7 is a diagram showing pulses input corresponding to dots in normal mode. (a) is a diagram showing pulses input corresponding to the first sub-dot of dots in high-speed printing mode. (b) is a diagram showing pulses input corresponding to the second sub-dot of the dots in the high-speed printing mode. (c) is a diagram showing a pulse input corresponding to the third sub-dot of the dots in the high-speed printing mode. (d) is a diagram showing a pulse input corresponding to the fourth sub-dot of the dots in the high-speed printing mode. 3 is a flowchart illustrating first print processing. FIG. 3 is a diagram showing print density with respect to gradation in high-speed printing mode. 7 is a flowchart showing second print instruction processing. 7 is a flowchart showing a second print process.

Hereinafter, first and second embodiments of the present invention will be described in detail in order with reference to the accompanying drawings. The embodiments described below have various limitations that are technically preferable for carrying out the present invention, but the scope of the present invention is not limited to the embodiments and illustrated examples below. do not have.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. 1 to 10. First, the device configuration of this embodiment will be described with reference to FIGS. 1 to 5. FIG. 1 is an external perspective view showing a thermal printer 20 according to the present embodiment. FIG. 2 is a block diagram showing the printing system 1. As shown in FIG. FIG. 3 is a block diagram showing the functional configuration of the PC 10. FIG. 4 is a block diagram showing the functional configuration of the thermal printer 20. As shown in FIG. FIG. 5 is a diagram showing a print image corresponding to an increase in the energization time for one dot.

As shown in FIG. 1, the thermal printer 20 is a printing device that prints images such as characters, marks, figures, and tables by heating a tape T1 as a printing medium. The thermal printer 20 has a function of printing in black and white with multiple gradations of printing density using white (no printing on the base (background, for example, white)) and black (black on the base). Further, the thermal printer 20 has a function of cutting the printed tape T1, a function of communicating with an external device via a wireless LAN (Local Area Network), and the like.

The tape T1 includes a printed tape body and a release paper for the tape body. The tape main body is a tape with a multilayer structure that integrally includes a laminate film, a coloring layer, a tape color layer, a base material, and an adhesive layer in order from the front surface to the back surface. The laminate film is a transparent protective layer and is made of, for example, PET (PolyEthylene Terephthalate). The coloring layer is a layer that develops a color when heated, and for example, the color develops is black. The tape color layer is a base layer of a color (for example, white) that serves as the base (background) of the printed coloring layer of the tape main body. In this way, the tape T1 (tape main body) will be described assuming that black is printed on a white background. However, the color of the tape color layer is not limited to white, and may be other colors such as yellow.

The base material is the base material of the tape main body, and is made of, for example, PP (PolyPropylene). The adhesive layer is an adhesive layer that allows the tape main body to be attached to an object and that can be peeled off from the release paper. In this manner, the user can peel off the printed adhesive layer of the tape main body from the release paper and apply the tape T1 to an object. Further, as the tape T1, tapes having various widths, for example, from 6 to 24 [mm] can be used.

The thermal printer 20 has a tape outlet 202, a tape remaining amount confirmation window 203, an open button 204, an operation section 22, and a display section 24 on a housing 201. The housing 201 houses a circuit configuration described later, a tape adapter 274 (FIG. 4) that supplies the tape T1, and the like. Furthermore, the casing 201 has a lid 201a, and the lid 201a can be opened in response to the user pressing an open button 204, allowing the tape adapter housed in the casing 201 to be replaced.

Tape outlet 202 is an outlet for printed tape T1. The tape T1 is wound around a cylindrical holding part (not shown) and set in the tape adapter 274. The remaining tape amount confirmation window 203 is a transparent window portion through which the user can observe the thickness of the tape T1 on the reel housed in the housing 201 as the remaining amount. The open button 204 is a button that accepts a press operation to open the lid 201a.

The operation unit 22 includes a power key 221, a cut key 222, and a wireless LAN switching key 223. The power key 221 is a key that accepts a press input to turn on/off the power of the thermal printer 20 . The cut key 222 is a key that accepts press inputs for cutting and feeding the tape T1. The wireless LAN switching key 223 is a key that accepts a press input for switching the wireless LAN communication mode of the thermal printer 20 between access point mode and client mode. The access point mode is a mode in which the thermal printer 20 functions as a wireless LAN access point, and the thermal printer 20 directly performs wireless LAN communication with an external device. The client mode is a mode in which the thermal printer 20 performs wireless LAN communication with an external device via a wireless LAN access point.

The display unit 24 includes a power lamp 241 and wireless LAN lamps 242 and 243. The power lamp 241 is a lamp that lights up while the thermal printer 20 is powered on. The wireless LAN lamp 242 is a lamp that lights up when the thermal printer 20 is in the wireless LAN access point mode. The wireless LAN lamp 243 is a lamp that lights up when the thermal printer 20 is in the wireless LAN client mode.

Next, with reference to FIG. 2, the printing system 1 including the thermal printer 20 will be described. As shown in FIG. 2, the printing system 1 includes a PC (Personal Computer) 10 as an external device and a thermal printer 20.

The PC 10 is an information processing device that generates image data for printing as print data and transmits it to the thermal printer 20 for printing. Although FIG. 2 shows a state in which the thermal printer 20 is communicating with the PC 10 via wireless LAN in access point mode, it is also possible to perform wireless LAN communication in client mode via an access point (not shown).

Next, with reference to FIG. 3, the internal functional configuration (circuit configuration) of the PC 10 will be explained. As shown in FIG. 3, the PC 10 includes a CPU (Central Processing Unit) 11, an operation section 12, a RAM (Random Access Memory) 13, a display section 14, a storage section 15, and a communication section 16. . Each part of the PC 10 is connected via a bus 17.

The CPU 11 controls each part of the PC 10. The CPU 11 reads out a designated program from among the various programs stored in the storage unit 15, expands it onto the RAM 13, and executes various processes in cooperation with the expanded program.

The operation unit 12 includes a keyboard and a pointing device such as a mouse. The operation unit 12 receives operation inputs from the user such as presses of keys on a keyboard and position information of a pointing device, and outputs operation signals based on the operation inputs to the CPU 11. Note that the operation unit 12 may include a touch panel that is integrally formed on the display screen of the display unit 14 and receives touch input from the user.

The RAM 13 is a volatile semiconductor memory from which information can be read and written. The RAM 13 provides a work area for the CPU 11 and temporarily stores data and programs.

The display unit 14 includes a display panel such as an LCD (Liquid Crystal Display) or an EL (Electro-Luminescence) display. The display unit 14 displays various display information input from the CPU 11 and the like on the display screen of the display panel.

The storage unit 15 is configured by an HDD (Hard Disk Drive), an SSD (Solid State Drive), etc., is a storage unit from which information can be read and written, and stores various data and various programs. In particular, the storage unit 15 stores a first print instruction program P1 for executing a first print instruction process to be described later.

The communication unit 16 includes an antenna for wireless LAN communication, a modulation/demodulation circuit, a signal processing circuit, and the like. The communication unit 16 performs wireless LAN communication with an external device directly (access point mode) or via an access point (client mode). The CPU 11 performs wireless LAN communication with a thermal printer 20 as an external device via the communication unit 16 to transmit and receive information.

Next, with reference to FIG. 4, the internal functional configuration (circuit configuration) of the thermal printer 20 will be described. As shown in FIG. 4, the thermal printer 20 includes a CPU 21, an operation section 22, a RAM 23, a display section 24, a storage section 25, a communication section 26, a printing section 27, and a detection section 28. . Each part of the thermal printer 20 is connected via a bus 29.

The CPU 21 controls each part of the thermal printer 20. The CPU 21 reads out a designated program from among the various programs stored in the storage unit 25, expands it into the RAM 23, and executes various processes in cooperation with the expanded program.

The operation unit 22 has a power key 221, a cut key 222, and a wireless LAN switching key 223. The operation unit 22 receives operation inputs of pressing each key from the user, and outputs operation signals based on the operation inputs to the CPU 21.

The RAM 23 is a volatile semiconductor memory from which information can be read and written. The RAM 23 provides a work area for the CPU 21 and temporarily stores data and programs.

The display section 24 includes a power lamp 241 and wireless LAN lamps 242 and 243. The display section 24 turns on/off the lighting of the power lamp 241 and the wireless LAN lamps 242 and 243 according to instructions from the CPU 21.

The storage unit 25 is a storage unit such as a ROM (Read Only Memory) from which at least information can be read. However, the storage unit 25 may be a storage unit such as a flash memory that can at least read and write information. In particular, it is assumed that the storage unit 25 stores a first print program P2 for executing a first print process to be described later.

The communication unit 26 includes an antenna for wireless LAN communication, a modulation/demodulation circuit, a signal processing circuit, and the like. The communication unit 26 performs wireless LAN communication with an external device directly (access point mode) or via an access point (client mode). The CPU 21 performs wireless LAN communication with the PC 10 as an external device via the communication unit 26 to transmit and receive information.

The printing section 27 includes a thermal head 271, a platen roller 272, a cutter 273, a tape adapter 274, and a drive section 275, and prints on the tape T1 under the control of the CPU 21.

The thermal head 271 is a print head that is placed on the conveyance path of the tape T1 and performs printing by heating the tape T1. Here, the conveying direction of the tape T1 is defined as a sub-scanning direction X, and the direction perpendicular to the conveying direction of the tape T1 (sub-scanning direction X) is defined as a main scanning direction Y. The thermal head 271 has, for example, one line of a plurality of heating elements arranged in a line in the main scanning direction Y. Under the control of the CPU 21, the thermal head 271 prints one line at a time on the tape T1 by heating, by selectively energizing a plurality of heating elements according to print data via the drive unit 275. Note that the thermal head 271 may have a plurality of lines of a plurality of heating elements arranged in a line in the main scanning direction Y, and may be configured to print on the tape T1 in a plurality of lines at a time.

Each heating element of the thermal head 271 corresponds to one dot printed on a printed material in a normal mode as a printing mode in which normal printing processing is performed. The print mode will be described in detail later. Pulses of a predetermined period (one unit time) are inputted to the heating element of the thermal head 271 by the head driving circuit of the driving section 275, and the heating element is energized according to the number of inputted pulses (number of pulses). . One unit time corresponds to the transfer time for transferring information for one gradation, and is not the energization time itself. Furthermore, in the normal mode, the gradation of one dot corresponds to the number of input pulses. Furthermore, the greater the number of pulses input to one heating element, the longer the energization time to that heating element. As shown in FIG. 5, when printing on the tape T1 with the thermal head 271, as the energization time to one heating element becomes longer, the area that can be heated by the heating element increases as shown in the arrow direction of FIG. The area of the heating area within the dot (indicated by the broken line in Figure 5) expands, and the area of the black area, which is the printed part, expands in proportion to the area of the heating area. ). When all areas within one dot become black areas, the area of the black area also reaches its maximum value, resulting in the maximum printing density. However, the spread of this area does not necessarily increase in direct proportion to the length of the current application time, and there remains room to improve the linearity of printing density with respect to gradation.

The platen roller 272 is a roller that is provided to face the thermal head 271 and conveys the tape T1 pulled out from the tape adapter 274 to the tape outlet 202 by rotating while holding the tape T1 pulled out from the tape adapter 274 between the platen roller 272 and the thermal head 271. Under the control of the CPU 21, the platen roller 272 is rotatably driven around a rotation axis through a drive unit 275 so as to be able to move up and down (contact and detach) in the direction of the thermal head 271, thereby coming into contact with the thermal head 271. The tape T1 is conveyed in the sub-scanning direction X to the tape outlet 202 so as to be printable.

The cutter 273 is disposed on the conveyance path of the tape T1, downstream of the thermal head 271 in the sub-scanning direction X (on the tape exit 202 side), and cuts the printed tape T1 under the control of the CPU 21. Department. The cutter 273 has a full cut mechanism that cuts the main body of the tape T1 and the release paper together (full cut), but is not limited to this, and cuts only the main body of the tape T1. It may also have a half-cut mechanism for (half-cutting).

The tape adapter 274 is an adapter that holds the wound tape T1 before printing. The tape adapter 274 sends out the tape T1 pulled by the rotation of the platen roller 272 toward the thermal head 271 side.

The drive unit 275 is a drive unit that drives the thermal head 271 , the platen roller 272 , and the cutter 273 . It has a rotating motor and a cutting drive mechanism of a cutter 273. Under the control of the CPU 21, the drive unit 275 heats each heating element of the thermal head 271 by a head drive circuit, raises and lowers the platen roller 272 by a platen roller lifting mechanism, rotates the platen roller 272 by a motor, and by a cutting drive mechanism of the cutter 273. Cut the tape.

The detection unit 28 includes a tape tip detection sensor that detects the tip of the tape T1, and a tape type detection sensor that detects the type (length (width) in the main scanning direction Y) of the tape T1. For example, the length (width) of the tape T1 in the main scanning direction Y may differ depending on the type of tape T1. The tape leading edge detection sensor is disposed on the conveying path of the tape T1 between the thermal head 271 and the cutter 273, and detects the leading edge of the tape T1 in the sub-scanning direction X, which is the conveying direction. The tape type detection sensor detects the type of tape T1 set in the tape adapter 274. The tape type detection sensor detects the type of tape T1 stored inside the tape adapter 274 by reading an identification mark attached to the tape adapter 274, for example. The detection unit 28 outputs to the CPU 21 detection information about the leading edge of the tape detected by the tape leading edge detection sensor and detection information about the tape type (width) detected by the tape type detection sensor.

Next, the operation of the printing system 1 of this embodiment will be explained with reference to FIGS. 6 to 10. FIG. 6 is a flowchart showing the first print instruction process. FIG. 7 is a diagram showing pulses input corresponding to the dots 30 in the normal mode. FIG. 8(a) is a diagram showing pulses input corresponding to the sub-dots 31 of the dots 30a in the high-speed printing mode. FIG. 8(b) is a diagram showing pulses input corresponding to the sub-dots 32 of the dots 30a in the high-speed printing mode. FIG. 8(c) is a diagram showing pulses input corresponding to the sub-dots 33 of the dots 30a in the high-speed printing mode. FIG. 8(d) is a diagram showing pulses input corresponding to the sub-dots 34 of the dots 30a in the high-speed printing mode. FIG. 9 is a flowchart showing the first printing process. FIG. 10 is a diagram showing print density with respect to gradation in high-speed printing mode.

First, with reference to FIG. 6, the first print instruction process executed by the PC 10 will be described. The PC 10 and the thermal printer 20 are powered on in advance, and wireless LAN communication is established in the access point mode or client mode via the communication units 16 and 26 (the PC 10 and the thermal printer 20 are connected for communication). ) shall be assumed.

In the PC 10, for example, when the user inputs an instruction to execute the first print instruction process via the operation unit 12 as a trigger, the CPU 11 executes the process according to the first print instruction program P1 stored in the storage unit 15. , executes the first print instruction process.

As shown in FIG. 6, first, the CPU 11 receives a selection input from the user via the operation unit 12 to select the normal mode or high-speed printing mode as the print mode (step S11). Here, each print mode will be explained with reference to FIGS. 7 to 8(d).

The normal mode is a printing mode in which black and white printing is performed in a predetermined plurality of gradations for each printed dot. Here, an example will be described in which black and white printing is performed with 256 gradations in which the gradation values range from 0 to 255. FIG. 7 is a diagram (graph) showing the dots 30 to be printed, the sub-scanning direction X and the main scanning direction Y of the dots 30, and the pulse voltage value with respect to time for each gradation (0 to 255) in the normal mode. , is shown.

Here, to simplify the explanation, an example will be described in which one pixel of image data to be printed corresponds to one dot printed by one of the plurality of heating elements of the thermal head 271 in the normal mode. . Note that a plurality of pixels of the image data to be printed may correspond to one dot of the heating element.

As shown in FIG. 7, when printing one dot 30, when the gradation is 0, a pulse of 1 unit time is not input to the heating element at all, the energization time of the heating element is also 0, and the printing density of the printed matter is The lowest value (white) is reached. When the gradation of the dot 30 is 1, one pulse of 1 unit time is input to the heating element, the heating element is energized for the energization time corresponding to the one input pulse, and the printing density of the printed matter is the same as the gradation. becomes darker (blacker) than the print density of 0. Similarly, as the gradation of the dots 30 becomes higher, the energization time corresponding to the number of pulses per unit input to the heating element becomes longer, and the print density of the printed matter becomes darker (blacker). When the gradation of dot 30 is 255, 255 pulses of 1 unit time (pulses of 255 unit time) are input to the heating element, and the heating element is activated for the energization time corresponding to the input 255 pulses. Electricity is applied, and the printing density of the printed matter becomes the darkest (black). In the normal mode, one dot (one dot 30) is printed corresponding to one heating element of the thermal head 271.

Time-divisionally controls the energization time to the heating element corresponding to one dot (the energization time for the maximum gradation for 1 dot is time-divided by the number of gradations, and the time-divided energization time is converted into pulses of 1 unit time) The method of expressing gradation by controlling the number of pulses input to the heating element is called the time division method. In other words, in the normal mode, multiple gradations are expressed and printed using the time division method.

The relationship between the gradation of the dots 30 and the energization time (ratio) in the normal mode is shown in Table I below. The energization time (ratio) in the normal mode is the ratio of the energization time for each gradation 0 to 255 to the energization time for the maximum gradation (here, 255) where the printing density is the darkest (blackest). In the case of the maximum gradation, the energization time (ratio) is 1. As shown in FIG. 7 and Table I, the energization time (ratio) corresponds to the number of pulses per unit time input to the heating element.

On the other hand, high-speed printing mode converts multiple dots of image data to be printed into one low-resolution dot, divides each low-resolution dot into multiple sub-dots, and converts each low-resolution dot into multiple sub-dots. This is a printing mode in which black and white printing is performed by expressing multiple gradations using one dot using the area gradation method and the time division method. The area gradation method is a method in which a matrix containing a plurality of subdots is set for one dot, and the density is changed in a pseudo manner depending on how many subdots are printed and arranged.

As shown in FIG. 8(a), here, four sub-dots 31, 32, 33, 34 in a matrix form are used to form one dot 30a (a dot with an area four times that of the sub-dots), and a dot in the normal mode. An example of expressing multiple gradations similar to No. 30 will be described.

The sub-dot 31 is the sub-dot arranged furthest in the -X direction and furthest in the -Y direction among the dots 30a. The sub-dot 32 is the sub-dot arranged furthest in the +X direction and furthest in the +Y direction among the dots 30a. That is, the sub-dots 32 are arranged diagonally in the main scanning direction Y and the sub-scanning direction X. The subdot 33 is a subdot adjacent to the subdot 31 in the +Y direction in the dot 30a, and is adjacent to the subdot 32 in the −X direction. The subdot 34 is a subdot adjacent to the subdot 31 in the +X direction in the dot 30a, and is adjacent to the subdot 32 in the −Y direction.

Here, an example will be described in which the gradation of the dot 30a is increased from 0. When increasing the gradation level of the dot 30a from 0, first, as shown in FIG. Expression) is increased from 0 to the maximum value (63). The maximum value of the sub-gradation of the sub-dot 31 is the maximum sub-gradation at which the printing density becomes the darkest (blackest) during printing. That is, the printing density of the maximum gradation (255) of the dot 30 in the normal mode and the printing density of the maximum sub-gradation (63) of the sub-dot in the dot 30a in the high-speed printing mode are the same. Furthermore, since one unit time of a pulse corresponds to the transfer time of information for one gradation, it is the same in the normal mode and the high-speed printing mode.

In addition, in high-speed printing mode, the maximum sub-gradation of each sub-dot is used to express the number of gradations from 0 to the maximum gradation of dot 30 in the normal mode using the sub-gradations of four sub-dots. is set to 63, which is about 1/4 of the maximum gradation (255) in the normal mode. Further, when the sub-gradation of the sub-dot 31 is increased from 0, it is assumed that the sub-gradation of the sub-dots 32 to 34 remains at 0. In the following description of the high-speed printing mode, a description of printing sub-dots whose sub-tones do not change will be omitted.

When printing one dot 30a, if the gradation of the dot 30a is 0, the sub-gradation of the sub-dot 31 is also 0, and the pulse of 1 unit time is not input to the heating element of the sub-dot 31 at all, and the heating element of the sub-dot 31 is The energization time also becomes 0, and the printing density of the sub-dots 31 of the printed matter becomes the lowest (white). Therefore, the print density of the dots 30a on the printed matter is also the lowest (white).

When the gradation of the dot 30a is 1, the sub-gradation of the sub-dot 31 is also 1, one 1-unit time pulse is input to the heating element of the sub-dot 31, and the energization time corresponding to one input pulse is The heating element is energized, and the print density of the sub-dots 31 of the printed material becomes darker (blacker) than the print density when the sub-gradation is 0. Therefore, the printing density of the dots 30a on the printed matter is darker (blacker) than the printing density when the gradation is 0, when the dots 30a are viewed as a whole.

Similarly, when the gradation of the dot 30a is raised, the sub-gradation of the sub-dot 31 also becomes higher, so the energization time corresponding to the number of pulses per unit input to the heating element of the sub-dot 31 also increases. As a result, the printing density of the sub-dots 31 on the printed material becomes darker (blacker), and the printing density of the dots 30a on the printed material also becomes darker (blacker).

When the gradation of the dot 30a is 63, the sub-gradation of the sub-dot 31 also becomes 63, which is the maximum value, and 63 1-unit time pulses (63 unit-time pulses) are applied to the heating element of the sub-dot 31. The heating element is energized for the energization time corresponding to the input 63 pulses, and the printing density of the sub-dots 31 of the printed matter becomes the deepest (blackest). For this reason, the printing density of the dots 30a on the printed matter also becomes the deepest (blackest) ever. In this way, the sub-dots 31 are printed in black and white with 64 sub-gradations from 0 to 63.

Relationship between the gradation of the sub-dot 31 and the energization time (ratio) when changing the gradation of the dot 30a from 0 to 63 in high-speed printing mode (when changing the sub-gradation of the sub-dot 31 from 0 to 63) The sub-gradations of sub-dots 32 to 34 are shown in Table II below. The energization time (ratio) in high-speed printing mode is the energization time for each sub-gradation 0 to 63 relative to the energization time for the maximum sub-gradation (63 in this case) where the print density of the sub-dot is the darkest (blackest). It is a percentage value. In the case of the maximum sub-gradation, the energization time (ratio) is 1. As shown in FIG. 8A and Table II, the energization time (ratio) of the sub-dots 31 corresponds to the number of pulses per unit time (sub-gradation) input to the heating element.

When the gradation of the dot 30a is made higher than 63, the sub-gradation of the sub-dot 31 is kept at the maximum value (63), and one sub-dot 32 is The sub gradation of is increased from 1 to the maximum value (63). It is assumed that the sub-dots 33 and 34 have the sub-gradation level 0.

In printing one dot 30a, if the gradation of the dot 30a is 64, the sub-gradation of the sub-dot 32 is 1, and one 1-unit time pulse is input to the heating element of the sub-dot 32, The heating element is energized for the energization time corresponding to one pulse, and the print density of the sub-dots 31 of the printed material becomes darker (blacker) than the print density when the sub-gradation is 0. Therefore, the printing density of the dots 30a on the printed matter is darker (blacker) than the printing density of the 63rd gradation.

Similarly, when the gradation of the dot 30a is raised, the sub-gradation of the sub-dot 32 also becomes higher, so the energization time corresponding to the number of 1 unit of pulses input to the heating element of the sub-dot 32 also increases. As a result, the printing density of the sub-dots 32 on the printed material becomes darker (blacker), and the printing density of the dots 30a on the printed material also becomes darker (blacker).

Then, when the gradation of the dot 30a is 126, the sub-gradation of the sub-dot 32 becomes 63, which is the maximum value, and 63 1 unit time pulses are input to the heating element of the sub-dot 32, and the input 63 The heating element is energized for the energization time corresponding to the pulses, and the print density of the sub-dots 32 on the printed matter becomes the darkest (black). For this reason, the printing density of the dots 30a on the printed matter also becomes the deepest (blackest) so far. In this way, the sub-dots 32 are printed in black and white with 63 sub-gradations from 1 to 63.

Relationship between the gradation of the sub-dot 32 and the energization time (ratio) when changing the gradation of the dot 30a from 64 to 126 in high-speed printing mode (when changing the sub-gradation of the sub-dot 32 from 1 to 63) The subgradations of the subdots 31, 33, and 34 are shown in Table III below. As shown in FIG. 8B and Table III, the energization time (ratio) of the sub-dots 32 corresponds to the number of pulses per unit time (sub-gradation) input to the heating element.

When the gradation value of the dot 30a is made higher than 126, as shown in FIG. The subgradation level of each subdot 33 is increased from 1 to the maximum value (63). It is assumed that the sub-dot 34 has a sub-gradation level of 0.

In printing one dot 30a, when the gradation of the dot 30a is 127, the sub-gradation of the sub-dot 33 becomes 1, and one 1-unit time pulse is input to the heating element of the sub-dot 33, The heating element is energized for the energization time corresponding to one pulse, and the printing density of the sub-dots 33 on the printed matter becomes darker (blacker) than the printing density when the sub-gradation is 0. Therefore, the printing density of the dots 30a on the printed matter is darker (blacker) than the printing density of the 126th gradation.

Similarly, as the gradation of the dot 30a is raised, the sub-gradation of the sub-dot 33 also becomes higher, so the energization time corresponding to the number of 1 unit of pulses input to the heating element of the sub-dot 33 also increases. As a result, the printing density of the sub-dots 33 on the printed material becomes darker (blacker), and the printing density of the dots 30a on the printed material also becomes darker (blacker).

Then, when the gradation of the dot 30a is 189, the sub-gradation of the sub-dot 33 becomes 63, which is the maximum value, and 63 1 unit time pulses are input to the heating element of the sub-dot 33, and the input 63 The heating element is energized for the energization time corresponding to the pulses, and the printing density of the sub-dots 33 on the printed matter becomes the darkest (black). For this reason, the printing density of the dots 30a on the printed matter also becomes the deepest (blackest) so far. In this way, the sub-dots 33 are printed in black and white with 63 sub-gradations from 1 to 63.

Relationship between the gradation of the sub-dot 33 and the energization time (ratio) when changing the gradation of the dot 30a from 127 to 189 in high-speed printing mode (when changing the sub-gradation of the sub-dot 33 from 1 to 63) The sub-gradations of sub-dots 31, 32, and 34 are shown in Table IV below. As shown in FIG. 8C and Table IV, the energization time (ratio) of the sub-dots 33 corresponds to the number of pulses per unit time (sub-gradation) input to the heating element.

When the gradation value of the dot 30a is made higher than 189, as shown in FIG. , the gradation of one sub-dot 34 is increased from 1 to the maximum value (63).

In printing one dot 30a, if the gradation value of the dot 30a is 190, the sub-gradation value of the sub-dot 34 is 1, and one 1-unit time pulse is input to the heating element of the sub-dot 34. The heating element is energized for the energization time corresponding to one input pulse, and the printing density of the sub-dots 34 on the printed material becomes darker (blacker) than the printing density when the sub-gradation is 0. Therefore, the printing density of the dots 30a on the printed matter is darker (blacker) than the printing density of the 189th gradation.

Similarly, as the gradation of the dots 30a is raised, the sub-gradation of the sub-dots 34 also becomes higher, so the energization time corresponding to the number of pulses per unit input to the heating element of the sub-dots 34 also increases. As a result, the print density of the sub-dots 34 on the printed material becomes darker (blacker), and the printing density of the dots 30a on the printed material also becomes darker (blacker).

Then, when the gradation of the dot 30a is the maximum value of 252, the sub-gradation of the sub-dot 34 is the maximum value of 63, and 63 pulses of 1 unit time are input to the heating element of the sub-dot 34, The heating element is energized for the energization time corresponding to the 63 input pulses, and the print density of the sub-dots 34 on the printed matter becomes the deepest (blackest). Therefore, the printing density of the dots 30a on the printed matter is also the highest (black). In this way, the sub-dots 34 are printed in black and white with 63 sub-gradations from 1 to 63.

Relationship between the gradation of the sub-dot 34 and the energization time (ratio) when changing the gradation of the dot 30a from 190 to 252 in high-speed printing mode (when changing the sub-gradation of the sub-dot 34 from 1 to 63) The sub-gradations of sub-dots 31 to 33 are shown in Table V below. As shown in FIG. 8D and Table V, the energization time (ratio) of the sub-dots 34 corresponds to the number of pulses per unit time (sub-gradation) input to the heating element.

In summary, in high-speed printing mode, the number of pixels printed is 1/4 lower resolution than in normal mode, but if the sub-gradation of each sub-dot of one dot is set to 64 or 63 gradations, Black and white printing is possible with a printing density of 253 gradations per dot, and the number of gradations is the same as in the normal mode (256 gradations). At this time, in the high-speed printing mode, since the number of pulse inputs per heating element is smaller than in the normal mode, the transfer time can be shortened, and as a result, the printing speed can be increased. In the high-speed printing mode, one sub-dot (sub-dot 31, 32, 33 or 34) of one dot (one dot 30a) is printed corresponding to one heating element of the thermal head 271.

Returning to FIG. 6, the CPU 11 receives a setting input for image data to be printed from the user via the operation unit 12 (step S12). In step S12, for example, image data such as characters, marks, figures, tables, etc. is stored in advance in the storage unit 15, and image data to be printed from among the stored image data is selectively input. Further, in step S12, for example, by executing the image data creation tool, image data to be printed is newly created or edited according to the user's operation input, and the newly created or edited image data is set as the image data to be printed. It may also be done. Further, in step S12, the communication unit 16 may access a content server on the Internet via a wireless LAN, and download image data to be printed from the content server in response to a user's operation input.

Then, the CPU 11 receives input of various print setting information from the user via the operation unit 12 (step S13). In step S13, for example, the type of tape T1 set in the tape adapter 274 detected by the detection unit 28 in the thermal printer 20 is received via the communication unit 16, and based on the type of tape T1, An image (width, etc.) of the tape T1 is displayed on the display section 14. The adjustment values for the position and size of the image data set in step S12 on the image of the tape T1 displayed on the display unit 14, the length of the tape T1 in the sub-scanning direction X to be cut after printing, etc. Entered as setting information.

Then, the CPU 11 determines whether a print instruction has been input by the user via the operation unit 12 (step S14). If no print instruction has been input (step S14; NO), the process moves to step S11. If a print instruction is input (step S14; YES), the CPU 11 selects the print mode (normal mode or high-speed print mode) input in step S11, the image data to be printed input in step S12, and the image data to be printed in step S13. The print setting information inputted in step S15 is generated, and the generated print data is transmitted to the thermal printer 20 via the communication unit 16 (step S15), and the first print instruction process is ended.

Next, with reference to FIG. 9, the first printing process executed by the thermal printer 20 will be described. In the thermal printer 20, for example, when the CPU 21 starts receiving the print data sent from the PC 10 via the communication unit 26 in step S15 of the first print instruction process in FIG. A first print process is executed according to the stored first print program P2.

As shown in FIG. 9, first, the CPU 21 completes receiving the print data transmitted in step S15 from the PC 10 via the communication unit 26 (step S21). Then, the CPU 21 refers to the print mode of the print data received in step S21 and determines whether or not it is the high-speed print mode (step S22).

If the high-speed printing mode is selected (step S22; YES), the CPU 21 acquires the image data and print setting information of the print data received in step S21, and prints the normal image data adjusted to the position and size of the image data of the print setting information. The image data for the mode is converted to low resolution for the high-speed printing mode (step S23). In step S23, for example, image data (gradation data of each pixel) of each dot 30 (FIG. 7, for example, 256 gradations) for each heating element of the thermal head 271 is generated from each pixel of the adjusted image data. From the image data of all the generated dots 30, four adjacent dots 30 in a 2×2 (rectangular) matrix are combined into a set (referred to as "matrix dots 30"), and each matrix is The gradation of dot 30 is determined. The gradation value of each matrix dot 30 is determined by the gradation value of the dot 30 at a predetermined position (for example, the position where the coordinate values in the sub-scanning direction X and main scanning direction Y are the smallest) among the matrix-shaped dots 30. The value of is determined as a representative value, but the value is not limited to this. For example, the average value of the gradations of four adjacent dots 30 may be calculated, and the average value may be determined as the gradation of the dot 30.

Then, the CPU 21 converts the low resolution image data converted in step S23 into image data of the dot 30a having sub-dots 31 to 34 (step S24). In step S24, from the image data of each matrix-like dot 30 converted in step S23 (gradation data of each dot of 256 gradations converted to a low resolution of 1/4 from the original adjusted image data), , is converted into image data (gradation data of each dot 30a with 252 gradations) of a (rectangular) matrix of dots 30a (FIGS. 8(a) to 8(d)) consisting of 2×2 sub-dots. . This conversion is based on the conversion method explained in FIGS. 8(a) to 8(d), from the gradation value of each matrix dot 30 to the gradation value of each sub-dot 31 to 34 of the dot 30a ( 64 gradations or 63 gradations) image data (gradation data of each dot 30a of 252 gradations converted to 1/4 resolution from the original adjusted image data).

Then, the CPU 21 causes the printing unit 27 to print an image on the tape T1 (high-speed printing), and the cutter 273 cuts the printed tape T1 (step S25), thereby ending the first printing process. In the high-speed printing in step S25, pulses are input to each heating element of the thermal head 271 according to the gradation values of the sub-dots 31 to 34 of the dot 30a of the converted image data, and electricity is applied to the heating element to print by heating the tape T1. Ru.

If the mode is the normal mode (step S22; NO), the CPU 21 acquires image data and print setting information from the print data, and converts the image data into image data for the normal mode based on the size and position of the image in the print setting information. (gradation data of each dot 30 of 256 gradations), and based on the length of the tape T1 of the obtained print setting information and the converted image data, the printing unit 27 prints the tape T1. The image is printed (normal printing), and the cutter 273 cuts the printed tape T1 (step S26), ending the first printing process. In normal printing in step S26, pulses are input to each heating element of the thermal head 271 according to the gradation value of the dot 30 of the converted image data, and electricity is supplied to print by heating the tape T1.

FIG. 10 shows the print density of an image printed on a printed matter (tape T1) in the high-speed printing mode corresponding to the gradation (256 gradations) of the image data of this embodiment. It can be seen that the printing density with respect to the gradation is approximately linear.

As described above, according to the present embodiment, the thermal printer 20 is a thermal printer that has a heating element in the thermal head 271 and prints on the tape T1 by energizing the heating element. When printing each dot 30 corresponding to a pixel of image data, the thermal printer 20 prints each dot 30 so that the number of sub-dots lined up in the main scanning direction Y is equal to the number of sub-dots lined up in the sub-scanning direction X. The gradation is expressed as a dot 30a by the area gradation method divided into sub-dots 31 to 34 so that the dot 30a is divided into sub-dots 31 to 34, and when printing each of the sub-dots 31 to 34, the energization time to the heating element is controlled in a time-sharing manner. It is equipped with a CPU 21 that performs gradation expression using a time division method. The CPU 21 determines the height relationship of the assigned gradations between the sub-dots lined up in the sub-scanning direction 252), the height relationship of the assigned gradations between subdots adjacent in the main scanning direction Y (subdots 33 and 32 adjacent to the subdots 31 and 34 in the main scanning direction Y) (the height relationship of the assigned gradation of the dot 30a assigned to the subdot 33), Gradation (127 to 189) > Gradation (64 to 126) of dot 30a assigned to sub-dot 32), while assigning the general outline expression in the gradation expression of dot 30 to the area gradation method, The detailed gradation expression of dot 30 (gradation expression of sub-dots) is assigned to the time division method.

Further, the dot 30 is divided into sub-dots 31, 32, 33, and 34 arranged in a matrix. The sub-dots 32 are arranged diagonally to the sub-dots 31 in the main scanning direction Y and the sub-scanning direction X. The subdots 33 are adjacent to the subdots 31 in the main scanning direction Y. The sub-dots 34 are adjacent to the sub-dots 31 in the sub-scanning direction X. As the gradation of the dot 30 (dot 30a) becomes higher, the CPU 21 increases the sub gradation (0→63), which is the gradation of the sub dot 31 (dot 30a), and increases the sub gradation of the sub dot 31 (dot 30a). When the tone reaches the maximum value (63), the sub-gradation of sub-dot 32 is raised (1 → 63) (gradation of dot 30a from 64 → 126), and the sub-gradation of sub-dot 32 reaches the maximum value (63). Then, the sub-gradation of sub-dot 33 is raised (1 → 63) (the gradation of dot 30a is increased from 127 → 189), and when the gradation of sub-dot 33 reaches the maximum value (63), the gradation of sub-dot 34 is increased. Increase (1→63) (gradation of dot 30a from 190→252). In this way, the gradations of the sub-dots 31 to 34 of the dot 30a (gradation (0 to 252)) are determined according to the gradation (0 to 255) of the dot 30.

Therefore, when printing multiple gradations in high-speed printing mode, although the resolution is low in terms of the number of dots, it is possible to maintain the number of gradations in each dot and increase the linearity of print density with respect to gradation. (FIG. 10), printing speed can be increased. In addition, by setting the gradation height relationship between sub-dots as described above, while assigning the large frame expression in gradation expression to the area gradation method, it is possible to avoid the visual discomfort caused by the coarsening of 1 dot size. The occurrence of can be suppressed.

Further, the CPU 21 sets the print mode to the high-speed printing mode or the normal mode in response to a selection operation between the high-speed printing mode and the normal mode via the operation unit 12 of the PC 10. Therefore, users can print by freely switching between high-speed printing mode, which has low resolution but relatively high printing speed, and high-speed printing mode, which has high resolution but relatively low printing speed, depending on the printing purpose. .

(Second embodiment)
A second embodiment according to the present invention will be described with reference to FIGS. 11 and 12. FIG. 11 is a flowchart showing the second print instruction process. FIG. 12 is a flowchart showing the second printing process.

In the first embodiment described above, the configuration is such that the user selects and inputs the normal mode/high-speed printing mode and prints with the thermal printer 20. In this embodiment, the thermal printer 20 is configured to print only in high-speed printing mode.

As for the device configuration, the printing system 1 is used as in the first embodiment. However, it is assumed that the storage unit 15 of the PC 10 stores a second print instruction program for executing a second print instruction process described later, instead of the first print instruction program P1. Further, it is assumed that the storage unit 25 of the thermal printer 20 stores a second print program for executing a second print process, which will be described later, in place of the first print program P2.

Next, the operation of the printing system 1 in this embodiment will be described with reference to FIGS. 11 and 12. First, with reference to FIG. 11, the second print instruction process executed by the PC 10 will be described. It is assumed that wireless LAN communication between the PC 10 and the thermal printer 20 has been established in advance in the printing system 1.

In the PC 10, for example, when a user inputs an instruction to execute the second print instruction process via the operation unit 12 as a trigger, the CPU 11 executes the second print instruction program stored in the storage unit 15. A second print instruction process is executed.

As shown in FIG. 11, steps S31 to S34 of the second print instruction process correspond to steps S12 to S15 of the first print instruction process of FIG. 6, respectively. However, the print data transmitted in step S34 does not include print mode selection information.

Next, the second printing process executed by the thermal printer 20 will be explained. In the thermal printer 20, for example, when the CPU 21 starts receiving the print data transmitted from the PC 10 in step S24 in FIG. The second printing process is executed according to the program.

As shown in FIG. 12, steps S41 to S44 of the second printing process correspond to steps S21 and S23 to S25 of the first printing process of FIG. 9, respectively. However, the print data received in step S41 does not include print mode selection information.

As described above, according to the present embodiment, in multi-gradation printing, it is possible to increase the linearity of the print density with respect to the gradation, and to lower the gradation of each sub-dot (energizing printing time), the resolution is lower but the printing speed can be increased.

In the above description, an example has been disclosed in which the storage section 25 such as ROM or flash memory is used as a computer-readable medium for the program according to the present invention, but the present invention is not limited to this example. As other computer-readable media, other nonvolatile memories, portable recording media such as CD-ROMs, etc. can be applied. Moreover, a carrier wave (carrier wave) is also applied to the present invention as a medium for providing data of the program according to the present invention via a communication line.

Note that the description in the above embodiment is an example of the thermal printer, printing method, and program according to the present invention, and the present invention is not limited thereto.

In the embodiment described above, the thermal printer 20 is a stationary type thermal printer having the operation section 22 consisting of a minimum number of buttons related to power supply and wireless LAN mode, but the present invention is not limited to this. For example, the thermal printer 20 includes an operation unit 22 having a keyboard, etc., and the user inputs steps S11 to S13 of the first print instruction process in FIG. 6 through the operation unit 22, and the second print instruction process in FIG. It is also possible to use a keyboard-type portable thermal printer that accepts similar operation inputs such as steps S31 and S32.

In addition, in the first embodiment, in response to the selection operation input of the normal mode/high speed printing mode from the user via the operation unit 12 of the PC 10, the CPU 21 of the thermal printer 20 selects the selected normal mode/high speed printing mode. Although the present invention has been described as having a configuration in which mode printing is performed, the present invention is not limited to this. Further, the operation unit 22 of the thermal printer 20 has a function of receiving an operation input for selecting the normal mode/high-speed printing mode, and in response to the operation input for selecting the normal mode/high-speed printing mode from the user via the operation unit 22. The configuration may be such that the CPU 21 performs printing in the selected normal mode/high speed printing mode.

Further, in the above embodiment, each of the dots 30a in the high-speed printing mode is divided into 2×2 sub-dots 31 so that the number of sub-dots lined up in the main scanning direction Y is equal to the number of sub-dots lined up in the sub-scanning direction. Although the structure is divided into 34 parts, the present invention is not limited to this. As a configuration in which the number of sub-dots lined up in the main scanning direction Y in each dot 30a is equal to the number of sub-dots lined up in the sub-scanning direction, other number combinations such as 3×3 may be used.

Further, in the above embodiment, the thermal printer 20 (printing section 27) is a printing section that prints on the tape T1 without using an ink ribbon, but is not limited to this, and prints on the tape T1 using an ink ribbon. It may also be a printing section that prints on the image. Printing using an ink ribbon is a printing method in which ink heated by heating an ink ribbon is applied onto a tape that does not have a coloring layer. Further, in the above embodiment, the thermal printer 20 (printing section 27) is configured to perform black and white printing, but the present invention is not limited to this. The thermal printer 20 (printing section 27) may be configured to perform color printing using ink ribbons of multiple colors.

Although the embodiments of the present invention have been described, the scope of the present invention is not limited to the above-described embodiments, but includes the scope of the invention described in the claims and equivalent ranges thereof.

1 Printing system 10 PC
11 CPU
12 Operation unit 13 RAM
14 Display section 15 Storage section 16 Communication section 17 Bus 20 Thermal printer 21 CPU
22 Operation unit 23 RAM
24 Display section 25 Storage section 26 Communication section 27 Print section 271 Thermal head 272 Platen roller 273 Cutter 274 Tape adapter 275 Drive section 28 Detection section 29 Bus

Claims (5)

A thermal printer that has a heating element and prints on a printing medium by energizing the heating element,
When printing each dot, each dot is divided into multiple subdots so that the number of subdots lined up in the main scanning direction and the number of subdots lined up in the subscanning direction are equal. a control unit that expresses gradation and uses a time-sharing method to control the energization time to the heating element in a time-sharing manner when printing each of the plurality of sub-dots;
The control unit controls the gradation so that the level relationship of assigned gradations between sub-dots arranged in the sub-scanning direction is different from the level relationship of assigned gradations between sub-dots adjacent in the main-scanning direction. assigning a general representation in tone representation to the area gradation method, while assigning detailed representation in the gradation representation to the time division method;
A thermal printer characterized by: The dots are divided into first, second, third and fourth sub-dots arranged in a matrix,
The second sub-dot is arranged diagonally to the main scanning direction and the sub-scanning direction of the first sub-dot,
the third sub-dot is adjacent to the first sub-dot in the main scanning direction,
the fourth sub-dot is adjacent to the first sub-dot in the sub-scanning direction,
As the gradation of the dot becomes higher, the control unit increases the subgradation that is the gradation of the first subdot, and when the subgradation of the first subdot reaches a maximum value, the controller increases the subgradation of the first subdot. When the sub-gradation of the second sub-dot is increased and the sub-gradation of the second sub-dot reaches its maximum value, the sub-gradation of the third sub-dot is increased and the sub-gradation of the third sub-dot is increased. increases the sub-gradation of the fourth sub-dot when becomes the maximum value;
The thermal printer according to claim 1, characterized in that: The control unit controls the gradation so that the level relationship of assigned gradations between sub-dots arranged in the sub-scanning direction is different from the level relationship of assigned gradations between sub-dots adjacent in the main-scanning direction. A high-speed printing mode that allocates the broad frame expression in the expression to the area gradation method while allocating the detailed expression in the gradation expression to the time division method and prints, and a high-speed printing mode that prints each dot using the time division method to print multiple gradations. and setting the printing mode to the high-speed printing mode or the normal mode according to the selection operation of the printing mode.
The thermal printer according to claim 1 or 2, characterized in that: A printing method for a thermal printer that has a heating element and prints on a printing medium by energizing the heating element, the method comprising:
When printing each dot, each dot is divided into multiple subdots so that the number of subdots lined up in the main scanning direction and the number of subdots lined up in the subscanning direction are equal. It includes a control step of expressing gradation and expressing gradation using a time-sharing method of controlling the energization time to the heating element in a time-sharing manner when printing each of the plurality of sub-dots;
In the control step, the gradation is controlled such that the height relationship of the assigned gradations between the sub-dots arranged in the sub-scanning direction is different from the height relationship of the assigned gradations between the sub-dots adjacent in the main-scanning direction. assigning a general representation in tone representation to the area gradation method, while assigning detailed representation in the gradation representation to the time division method;
A printing method characterized by: A thermal printer computer that has a heating element and prints on a printing medium by energizing the heating element,
When printing each dot, each dot is divided into multiple subdots so that the number of subdots lined up in the main scanning direction and the number of subdots lined up in the subscanning direction are equal. Functions as a control means to express gradation and to express gradation by a time-sharing method that controls the energization time to the heating element in a time-sharing manner when printing each of the plurality of sub-dots;
The control means controls the gradation so that the level relationship of assigned gradations between sub-dots arranged in the sub-scanning direction is different from the level relationship of assigned gradations between sub-dots adjacent in the main-scanning direction. assigning a general representation in tone representation to the area gradation method, while assigning detailed representation in the gradation representation to the time division method;
A program characterized by:

Images