JP2843051B2 - Thermal printer - Google Patents

Description

Description of the Invention (Object of the Invention) (Field of Industrial Application) The present invention relates to a thermal printer for printing on thermal recording paper, and more specifically, it corresponds to a predetermined number of digits of a character to be printed. The present invention relates to a thermal printer that prints on thermal recording paper by efficiently controlling a line thermal head.

(Prior art) When a printer is mounted on a handy terminal that can perform various data processing while being small and portable, the range of use can be further expanded and it becomes very convenient. As a printer that can be mounted on such a handy terminal, a thermal printer is generally used.

Thermal printers have the advantages of being quiet, having a relatively simple structure, and being extremely easy to handle, and are ideal for handy terminals, etc., but use special thermal recording paper as printing paper. The printing is performed by pressing the heating resistor of the thermal head against the thermal recording paper.

Further, in order to print one line of a plurality of characters, the thermal printer is a line thermal printer in which a plurality of heating resistors for printing dots of one line of the plurality of characters are arranged in a line in a line. The bed is used to drive a plurality of heating resistors constituting the line thermal head to print characters.

(Problems to be Solved by the Invention) As described above, when driving a plurality of heating resistors constituting a line thermal head in a thermal printer, if all the plurality of heating resistors are driven simultaneously, the printing speed is increased. However, when a thermal printer is used for a battery-driven device such as a handy terminal, the battery capacity is insufficient, so that a plurality of heating resistors cannot all be driven at the same time. There is.

In addition, if the battery capacity is increased, a plurality of heating resistors can be driven at the same time, but the size of the battery is increased. As a result, the size of the handy terminal is increased, which is not suitable for carrying. is there.

Also, if the thermal head is divided into groups of a predetermined number of dots and divided and driven in order for each group, there is no need to increase the battery capacity, but the number of times the thermal head is driven increases, so the printing speed is reduced. There is a problem that it becomes slow.

The present invention has been made in view of the above, and an object of the present invention is to consider a battery capacity and to reduce the number of times of driving at the time of printing, and as a result, a thermal printing that can perform high-speed printing It is intended to provide a printer.

[Configuration of the invention]

(Means for Solving the Problems) In order to achieve the above object, a thermal printer of the present invention uses a thermal head composed of a plurality of heating resistors arranged in a line to record symbols including characters and symbols. A thermal printer for printing on paper, wherein a plurality of heating resistors of the thermal head are divided into groups each having a predetermined number of dots, and provided in correspondence with each group to drive the heating resistors in units of the groups. A plurality of drivers, dot counting means for counting the number of dots included in the symbols to be printed for each group of the heating resistors when printing a predetermined symbol, and counting by the dot counting means. The first determination is to determine the total number of dots of all groups and determine whether the total number of dots is equal to or less than a predetermined number of simultaneously operable dots. Means for simultaneously driving all groups of the heating resistors by the plurality of drivers when the number of dots is equal to or less than the number of dots that can be simultaneously driven by the first determination means; If the determination unit determines that the total number of print dots exceeds a predetermined number of simultaneously operable dots, the number of dots of the group having the smallest number of dots among the numbers of dots for each group Determining whether or not exceeds a predetermined half of the number of simultaneously operable dots, and determining that the number of the simultaneously operable dots exceeds half of the predetermined number of simultaneously operable dots. In this case, the second driving means for driving each group of the heating resistors for each of the plurality of drivers and the second determination means determine that the number of dots that can be simultaneously driven does not exceed half the number of dots. Place And having a third driving means for driving a combination of each group of the heat generating resistor by the plurality of drivers upon which to determine the combination of a group of simultaneously drivable heating resistor.

(Operation) In the thermal printer of the present invention, when the plurality of heating resistors of the thermal head are divided and driven by counting the number of dots, it is first determined whether or not to drive them simultaneously.
If the number of dots that can be simultaneously driven is exceeded, it is determined whether the number of dots in the group with the smallest number of dots is more than half of the number of dots that can be simultaneously driven, and the heating resistor is driven for each group. It is determined whether to drive in combination.

(Example) Hereinafter, an example of the present invention is described using a drawing.

FIG. 1 is a perspective view showing an external configuration of a handy terminal to which a thermal printer according to an embodiment of the present invention is applied. The handy terminal shown in FIG. 1 has a thermal printer 1 according to an embodiment of the present invention mounted on the upper portion thereof. In the drawing, the thermal recording paper 3 printed by the thermal printer 1 is shown being fed out. ing.

The handy terminal shown in FIG. 1 has a liquid crystal display (LCD) 5 for displaying various data below the thermal printer 1 and further inputs various data and command information below the liquid crystal display 5. Keyboard 7 is provided.

FIG. 2 is a block diagram showing an overall circuit configuration of the handy terminal shown in FIG. As shown in the figure, the handy terminal has a CPU 11 composed of a 16-bit microprocessor for controlling the whole, in addition to the thermal printer 1, the liquid crystal display 5 and the keyboard 7 shown in FIG. A 64 KB ROM 13 which is connected via a bus 12 and stores fixed data and various data processing programs, a 256 KB, 512 KB or 768 KB RAM 15 for temporarily storing various data, a time and a date A clock / calendar 17 for clocking the time, a first kanji ROM 19 for storing JIS first-level kanji, a second kanji RAM 21 for storing JIS second-level kanji, A keyboard interface 23; an LCD controller 25 for the liquid crystal display 5; a backlight 27 for the liquid crystal display 5;
Printer controller 29 and buzzer controller 31
And a buzzer 33 driven by the buzzer controller 31,
A communication interface 35 for communicating with an external device; an interface connector 37 and an optical coupling element 39 connected to the communication controller 35; a time 41 for measuring various times; an RS-232C interface 43; RS-232CI / F connector 45 connected to 232C interface 43
, An MS reader controller 47, a memory card reader / writer controller 51 for writing / reading data to / from a memory card, an IC card reader / writer controller 55 for writing / reading data to / from an IC card, and the entire handy terminal. It has a cartridge-type main battery 59 for supplying an operating voltage, a sub-battery 61 for supplying a buffer-up voltage to the RAM 15 and the clock / calendar 17, and also has the MS reader connector 47, a memory card reader / writer controller 51. As shown by the dotted lines, the MS reader connector 49, the memory card R / W connector 53, and the IC card R / W connector 57 can be connected to the IC card reader / writer controller 55, respectively.

FIG. 3 is a circuit diagram of the printer controller 29 for controlling the thermal printer 1. As shown in the figure, the printer controller 29
A control unit 63 for receiving data to be printed from the CPU 11 and the kanji ROMs 19 and 21 via the data bus 12 and controlling a printing operation; and Is connected to the shift register 65 and the control unit 63 for sequentially receiving the received print data, counts the number of dots of the print data sequentially output from the shift register 65, and controls the dot count value. A first counter connected to an output of the shift register 65 for temporarily storing print data from the shift register 65 and driving a plurality of heating resistors constituting a thermal head; 4 and the buffer drivers 69a to 69d shown in FIG.
9d, each of which is composed of more than 384 heating resistors R1 to R384 arranged in a line in a line so as to constitute a line thermal head.

As shown in FIG. 1, since the thermal printer 1 is used for a handy terminal, printing is performed on a relatively narrow thermosensitive recording paper 3 in the width direction of the thermosensitive recording paper 3. Prints up to 16 digits of 24 dots horizontally. In the case of alphanumeric characters, 12-bit horizontal alphanumeric characters can be printed up to 32 digits. Also, since the number of dots in the vertical direction is 24 dots, characters such as kanji are 24 dots ×
24 dots represent one character, and alphanumeric characters represent one character by 12 dots x 24 dots.

Therefore, this thermal printer 1 prints 384 characters corresponding to 24 × 16 = 384 dots serially arranged in one line in a line as described above in order to print characters of 24 dots in width up to 16 digits in one line. Using a line thermal head composed of the heating resistors R1 to R384, while driving the 384 heating resistors R1 to R384, the thermal recording paper 3 is moved in the longitudinal direction by 24 dots each having a length equivalent to one dot. By feeding out the characters, 24 dots x 24 dots characters can be printed.

Also, 384 heating resistors R1 to R3 corresponding to 384 dots
When the 84 is driven at the same time, the main battery 61
384 heating resistors R1 to R384
The first heating resistor group RG1 is composed of heating resistors R289 to R384, and the second heating resistor group RG2 is composed of heating resistors R193 to R288, as shown in FIG. , A third heating resistor group RG3 including the heating resistors R97 to R192, and a fourth heating resistor group RG4 including the heating resistors R1 to R96, each of which is a buffer driver 69a to 69d.
It is driven by. Note that each buffer driver
69a to 69d are controlled by drive signals S1 to S4 from the control unit 63,
When the drive signals S1 to S4 are supplied, each buffer driver
Reference numerals 69a to 69d drive the corresponding heating resistor groups.

As described above, the number of the heating resistors in each of the four groups, that is, the first heating resistor group RG1 to the fourth heating resistor group RG4, is 96. In this embodiment, up to 96 heating resistors are controlled so that they can be driven simultaneously. In this case, the number of dots included in the character to be printed is counted by the counter 67, instead of simply driving each heating resistor group one by one, and each heating resistor group is counted according to the number of dots. The groups are appropriately driven, specifically, all the heating resistor groups are driven simultaneously or separately, etc., thereby improving the printing speed. Specifically, the characters to be printed are not all dots but a combination of dots.Therefore, some characters have a small number of dots. According to the number, all the heating resistors are simultaneously driven, that is, all the heating resistor groups are simultaneously driven.

Next, the operation will be described with reference to the flowchart shown in FIG.

In the flowchart of FIG. 4, it is assumed that the above-mentioned 384 heating resistors can be simultaneously driven up to 96 corresponding to each heating resistor group, and the first heating resistor group RG
The dot patterns of characters temporarily stored in the buffer drivers 69a to 69d respectively driving the first to fourth heat generating resistor groups RG4 are X1, X2, X3, X4, respectively, and these dot patterns X1 to X4 , The number of dots counted by the counter 67, respectively, N1, N2, N
3, N4, the numbers of dots N1, N2, N3, N4 are sorted in descending order, and the sorted dot numbers are sorted in descending order, n1, n
2, n3, n4 and the dot patterns X1, X2, X3, X4 of the characters with the rearranged dot numbers n1, n2, n3, n4
The dot pattern of each character corresponding to
It is represented as 2 ', X3', X4 '.

In FIG. 4, first, the dot numbers n1, n2, n3, n4
It is checked whether or not the dot total value obtained by adding all the characters is 96 or less (step 110). If the total value is 96 or less, the dot pattern X1 ', X2', X3 ', X4' of the character is changed to "+ "
Drive at the same time as indicated by the symbols (step 12
0). In step 110, if the total dot value is greater than 96, it is checked whether or not the number of dots n4 is greater than 96/2 = 48 (step 130).
2 ', X3', X4 'are separately driven (step 14
0).

If it is determined in step 130 that the number of dots n3 is not larger than 96/2 = 48, it is checked whether or not the dot number n3 is larger than 96/2 = 48 (step 150). It is checked whether n3 + n4 is greater than 96, and if it is, X1 ', X2', X3 ', X4' are separately driven (step 170). Step 1
If it is not large at 60, X1 'and X2' are driven independently, and X3 'and X4' are simultaneously driven (step 180).

Further, in step 150, if n3 is not greater than 96/2 = 48, the process proceeds to step 190, where n1 + n4 and n1
It is checked whether both 2 + n3 are less than 96, and if both are less than 96, as shown in step 200, X1 'and X1'
4 'are driven simultaneously, and X2' and X3 'are driven simultaneously. If not less than 96, proceed to step 210, where n2
+ N3 + n4 is checked whether it is 96 or less, and if it is 96 or less, X1 'is driven alone and X2', X3 'and X2'
4 'are simultaneously driven (step 220). If not less than 96, X1 'and X2' are driven independently, and X3 'and X2'
And 4 'are simultaneously driven (step 230).

〔The invention's effect〕

As described above, according to the present invention, when the plurality of heating resistors of the thermal head are divided and driven by counting the number of dots, it is first determined whether or not to perform simultaneous driving, and furthermore, simultaneous driving is possible. If the number of dots exceeds the minimum, it is determined whether the number of dots in the group with the smallest number of dots is more than half the number of dots that can be simultaneously driven, and whether each group of heating resistors is driven or combined. In a device such as a handy terminal that uses a battery as a driving power source, it is possible to reduce the number of times of driving at the time of printing, and as a result, it is possible to perform high-speed printing .

[Brief description of the drawings]

FIG. 1 is a perspective view showing the overall appearance of a handy terminal using a thermal printer according to one embodiment of the present invention, FIG. 2 is a block diagram showing the overall circuit configuration of the handy terminal of FIG. FIG. 4 is a diagram showing a circuit configuration of a printer controller used in a circuit block of the handy terminal shown in FIG. 2, and FIG. 4 is a flowchart showing an operation of the thermal printer having a circuit configuration shown in FIG. 1 ... thermal printer, 3 ... thermal recording paper, 63 ... control unit, 65 ... shift register, 67 ... counter, 69a to 69d ... buffer driver, RG1 to RG4 ... heating resistor group.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-62-290556 (JP, A) JP-A-63-67162 (JP, A) JP-A-56-106811 (JP, A) (58) Field (Int.Cl. ⁶ , DB name) B41J 2/35-2/37

Claims (2)

(57) [Claims] 1. A thermal printer for printing symbols including characters and codes on recording paper using a thermal head comprising a plurality of heating resistors arranged in a line, wherein the plurality of heating resistors of the thermal head are provided. The body is divided into groups of a predetermined number of dots, and a plurality of drivers are provided corresponding to each group to drive the heating resistors in units of the groups. Dot counting means for counting the number of dots included in the symbol to be printed for each resistor group; and calculating the sum of the dot numbers of all the groups counted by the dot counting means. First determining means for determining whether or not the number is equal to or less than a predetermined number of simultaneously operable dots; A first driving unit for simultaneously driving all groups of the heating resistors by the plurality of drivers; and a total number of printing dots determined by the first determination unit is a predetermined number of simultaneously drivable dots. When it is determined that the number of dots is exceeded, it is determined whether or not the number of dots of the group having the smallest number of dots among the numbers of dots of each group exceeds half of a predetermined number of simultaneously drivable dots. A second determining unit that, when the second determining unit determines that the number of dots that can be simultaneously driven exceeds half, drives each group of the heating resistors for each of the plurality of drivers; If it is determined by the second driving means that the number of dots that can be simultaneously driven is not more than half of the number of dots that can be simultaneously driven, the combination of groups of heating resistors that can be simultaneously driven is determined. Thermal printer characterized in that it comprises a third driving means for driving a combination of each group of the heat generating resistor by the plurality of drivers. 2. The method according to claim 1, wherein the first determining means sorts the number of dots of each group counted by the dot counting means in ascending and descending order, and obtains the sum of the numbers of dots of all the groups. And determining whether the number is equal to or less than a predetermined number of simultaneously drivable dots, wherein the third driving means exceeds half of the number of simultaneously drivable dots by the second determination means. If it is determined that there is no dot, the number of dots in the group having the second smallest number of dots out of the number of dots in each of the groups sorted by the first determination means is a predetermined number of simultaneously operable dots. A fourth determining means for determining whether or not the number of dots exceeds half of the number of dots. If the number of dots that can be simultaneously driven by the fourth determining means does not exceed half, the group having the smallest number of dots and the number of dots Discriminating means for discriminating whether there is another combination other than the combination with the second smallest group, and when the discriminating means determines that there is another combination, the plurality of drivers perform the discrimination. Means for driving each group of the heating resistors determined by the means, and when the determination means determines that there is no other combination, the plurality of drivers determine the group having the smallest number of dots and the number of dots. 2. The thermal printer according to claim 1, wherein the thermal printer is driven in combination with the second smallest group.