JP2933694B2 - Serial printer - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a multi-row wire head in a serial impact printer.

2. Description of the Related Art Conventionally, there has been provided a serial printer having a multi-row wire head in which the number of pins simultaneously impacted is reduced in order to reduce printing noise.

FIG. 7 is a diagram showing a wire arrangement of a multi-row wire head in a conventional serial impact printer.

In the figure, 2, 4, 6, ... 24 are even-numbered wires arranged in a "-" shape, and 1, 3, 5, ... 23 are odd-numbered wires arranged in a "reverse" shape. Are shown. Both the vertical dimension and the horizontal dimension between each of the even-numbered wires 2, 4, 6, ... 24 and between the odd-numbered wires 1, 3, 5, ... 23
It is 2/180 inches. The even wires 2, 4, 6, ... 24 and the odd wires 1, 3, 5, ... 23 are vertically shifted by 1/180 inch.

In the serial impact printer, printing is performed by selectively driving each of the wires 1, 2, ... 24 while moving the multi-row wire head having the above arrangement in the horizontal direction (lateral direction).

An operation in the case where printing is performed with a dot density in the horizontal direction of 180 dots / inch (hereinafter, referred to as “DPI”) using the multi-row wire head having the above configuration will be described.

FIG. 8 is a printing timing chart using a conventional multi-row wire head. In a multi-row wire head in a serial impact printer, the multi-row wire head is moved horizontally, and is driven when the wire reaches a printing position.

In the figure, the vertical line is the printing position formed every 1/180 inch, and the wire whose center reached the printing position is
The wires that have not been reached are indicated by ○. As shown in the drawing, half of the wires of the multi-row wire head are driven simultaneously, and each wire is selectively driven by print data. That is, at timing 1, all the 12 odd-numbered wires have reached the printing position, so that they can be driven simultaneously. At this time, the even-numbered wires are not driven because they have not reached the printing position. Next, at timing 2, twelve even-numbered wires reach the printing position at the same time, so that they can be driven simultaneously. At this time, since the odd-numbered wires have not reached the printing position, they are not driven. 18
The printing of 0DPI is performed by repeating the printing at the above two types of timing.

FIG. 9 is a drive circuit diagram of a multi-row wire head in a conventional serial impact printer, FIG. 9 (A) is a drive circuit diagram of an odd number wire, and FIG. 9 (B) is a drive circuit diagram of an even number wire. .

In FIG, Tr _1, Tr _2, ... Tr ₂₄ in each end the drive power source, the wire 1 at the other end, a transistor ... 24 are connected, the transistors Tr _1, Tr _2, ... Tr ₂₄ the base is made inverter a _1, a _2, via a ... a ₂₄ to drive signals of each wire is input. D _1, D _2, ... D ₂₄ Each transistor Tr _1, Tr _2, ... Tr ₂₄ and the wire 2, a diode for flyback is tangential to ... 24.

Q ₁ is a transistor for turning on / off the drive current flowing through all of the odd-numbered wires 1, 3,... 23. The collector is connected to each of the wires 1, 3,. , The base is connected to the inverter b, and the inverter b
, An odd-numbered wire drive signal is input. Q ₂ turns on the drive current flowing through all wires 2,4, ... 24 of the even-numbered wires.
A transistor for turning off, the collector is connected to each of the wires 2, 4,..., The emitter is connected to the ground, the base is connected to the inverter b, and an even-numbered wire drive signal is input via the inverter b.

That is, in order to perform printing at 180 DPI, 24 sets of drive circuits for each wire, a set of drive circuits common to all odd-numbered wires, and one set of drive circuits common to all even-numbered wires are provided.

(Problems to be Solved by the Invention) However, the multi-row wire head in the conventional serial impact printer cannot print at different dot densities because it supports various print modes.

FIG. 10 is a printing timing chart when printing is performed at 120 DPI with the multi-row wire head having the wire arrangement shown in FIG.

In the figure, the vertical line is a printing position formed every 1/120 inch, and a wire whose center has reached the printing position is indicated by ●, and a wire which has not reached the printing position is indicated by ○. As shown in the figure, at timing 1, the odd-numbered wires 5, 11, 13, 19 and the even-numbered wires 6, 12, 14, 20, 20 and at timing 2, the odd-numbered wires 3, 9, 15, 21 and the even numbered wires. At timing 3, odd numbered wires 2,8,24 and odd numbered wires 1,7,17,23 and even numbered wires
4, 10, 16, and 22 simultaneously reach the printing position. That is, at each timing, it is necessary to simultaneously print four wires each of an odd number and an even number.

And when printing at a different dot density,
The combination of wires for simultaneous printing changes again. Therefore, when printing is performed at different dot densities corresponding to the printing modes, it is impossible to have a common drive circuit for the odd-numbered wires and the even-numbered wires as shown in FIG. In addition, it is necessary to separately provide the lower drive circuit, and the drive circuit becomes very complicated.

The present invention solves the problems of the multi-row wire head in the conventional serial impact printer described above, and is capable of reducing print noise and printing at various dot densities. It is an object of the present invention to provide a multi-row wire head.

(Means for Solving the Problems) For this purpose, the serial printer of the present invention performs printing at a plurality of dot densities.

Then, a plurality of printing elements arranged on a plurality of printing element rows set at a fixed interval and a drive signal for independently driving each of the printing elements in accordance with print data are supplied. Means for dividing the plurality of printing element arrays into a plurality of groups and providing a common drive signal to printing elements on each printing element array in each group.

Further, the density in the horizontal direction of the printing elements on the different printing element rows in the group is set to the density of the least common multiple of the plurality of dot densities.

(Operation) According to the present invention, as described above, the serial printer
Print at multiple dot densities.

Then, a plurality of printing elements arranged on a plurality of printing element rows set at a fixed interval and a drive signal for independently driving each of the printing elements in accordance with print data are supplied. Means for dividing the plurality of printing element arrays into a plurality of groups and providing a common drive signal to printing elements on each printing element array in each group.

Further, the density in the horizontal direction of the printing elements on the different printing element rows in the group is set to the density of the least common multiple of the dot densities.

In this case, a drive signal for independently driving each print element corresponding to print data, and a common drive signal for print elements on each print element row in each group are generated, and according to the two drive signals, Printing is performed.

Therefore, the printing elements on each printing element row in each group are simultaneously driven by the two drive signals.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram showing a wire arrangement of a multi-row wire head in a serial impact printer of the present invention.

In the figure, 2, 4, 6,..., 24 are each of even-numbered wires arranged in a substantially “C” shape, and 1, 3, 5,.
Each of the odd-numbered wires arranged in a letter shape is shown. Each wire 2,4,6,… 24 of the even-numbered wires is wire 2,4,
Pairs are formed like wires 6, 8, and wires 10, 12, and each pair is arranged alternately up and down. Similarly, each of the odd-numbered wires 1, 3, 5,..., 23 also has wires 1, 3, wire 5, 7,
A pair is formed like the wires 9 and 11, and each pair is arranged alternately up and down.

The vertical dimension between each wire 2,4,6, ... 24 of the even-numbered wires and each wire 1,3,5, ... 23 of the odd-numbered wires is 2/180 inch, and each wire 2 of the even-numbered wires is , 4, 6, ... 24 and the odd numbered wires 1, 3, 5, ... 23 are alternately shifted by 1/180 inch.

On the other hand, the lateral dimension between each pair is 1/120 inch. Since the above-described pairs are alternately arranged vertically, the horizontal dimension between the upper pair and the lower pair is 1/60 inch.

The multi-row wire head having the above arrangement is mounted on a carriage (not shown) and moved in a horizontal direction (horizontal direction). On the other hand, the printing paper is sent by rotating a platen (not shown), 2, 24 are selectively driven to print on printing paper.

FIG. 2 is a block diagram of a serial impact printer to which the multi-row wire head of the present invention is applied.

In the figure, a CPU 31 reads and executes a control program written in a ROM 32 to control the entire serial impact printer. The ROM 32 is a read-only memory storing a control program and a dot matrix pattern of characters.

The RAM 33 is a writable / readable memory for recording all control of the serial impact printer and recording data. Reference numeral 34 denotes an I / O port through which the CPU 31 performs input / output of signals.
The AM 33 and the I / O port 34 are connected to each other by a bus 35.

The I / O port 34 is connected to the host computer via an interface signal, and outputs signals for driving the space motor 37, the line feed motor 38, and the print head 39, respectively. A slit signal is input from the attached slit. The polarity of the slit signal is inverted each time the carriage moves 1/360 inch horizontally. The I / O port 34 is connected to the space motor 37 via the space motor drive circuit 41, connected to the line feed motor 38 via the line feed motor drive circuit 42, and connected to the print head 39 via the print head drive circuit 43. It is connected.

The I / O port 34 is connected to the host computer via an interface signal, and outputs signals for driving the space motor 37, the line feed motor 38, and the print head 39, respectively. A slit signal is input from the attached slit. The polarity of the slit signal is inverted each time the carriage moves 1/360 inch horizontally. The I / O port 34 is connected to the space motor 37 via the space motor drive circuit 41, connected to the line feed motor 38 via the line feed motor drive circuit 42, and connected to the print head 39 via the print head drive circuit 43. It is connected.

Next, the operation of the multi-row wire head in the serial impact printer of the present invention will be described with reference to FIGS.

FIG. 3 is a signal waveform diagram of a multi-row wire head in the serial impact printer of the present invention, and FIG. 4 is a printing timing chart by the multi-row wire head in the serial impact printer of the present invention.

When character data from a host computer (not shown) is input to the I / O port 34 via the interface cable, the CPU 31 sequentially reads the character data and stores the character data in a character buffer area in the RAM 33. When the character data sent from the host computer becomes a one-line sentence, the data reception is suspended, and the character data expansion processing, that is, the conversion processing to character pattern data is performed. At this time, character data is read one character at a time from the character buffer area in the RAM 33, and a dot matrix pattern corresponding to the character data is read from the ROM 32 and stored in the image buffer in the RAM 33.

The data in this image buffer is printed as follows. The CPU 31 first starts moving the space motor 37 in the horizontal direction by writing to the I / O port 34. Then, while the space motor 37 is rotating, the slit signal is read,
Always monitor the position of the carriage. When the print position is 180 DPI, when the position of the carriage reaches the print start position, first, as shown in FIG. 3, the data corresponding to 1 to 12 of the print data in the first column in the RAM 33 is transferred to the I / O port. The upper drive signal is set to “1” at the same time as writing to 34. When "0" is written into a predetermined signal after a lapse of a predetermined time, the wires of the multi-row wire head are driven, and the upper data of the first column is printed. Timing 1 in FIG. 4 shows the position of the printable wire in this case.

In FIG. 4, the vertical lines are printing positions formed every 1/180 inch, and the wire whose center has reached the printing position is indicated by ●, and the wire which has not reached the printing position is indicated by ○. When the carriage advances 1/360 inch, the data corresponding to 13 to 24 of the print data of the first column is written to the I / O port 34, and at the same time, the lower drive signal is set to "1". By setting each signal to "0", printing is performed for the data corresponding to the lower wire in the print data of the first column. Timing 2 shows this state.

Further, each time the carriage advances by 1/360 inch, the upper side printing and the lower side printing are alternately repeated for the print data of the second and subsequent columns, and one line printing is performed.

Next, an operation when printing is performed at 120 DPI will be described.

FIG. 5 is a signal waveform diagram of a multi-row wire head when the serial impact printer of the present invention is used in another print mode, and FIG. 6 is a signal waveform diagram when the serial impact printer of the present invention is used in another print mode. It is a printing timing chart by a column wire head.

When the position of the carriage reaches the print start position, first of all, print data 1 to 24 of the print data of the first column are written to the I / O port 34, and the upper drive signal and the lower drive signal are set to "1". After a certain time, “0” is written to each signal. Each signal is driven by this signal, and the data of the first column is printed. Timing 1 in FIG. 6 shows the position of the driven wire and the head in this case. In this case, the vertical line indicates the print position formed every 1/120 inch, and the black circle indicates the position of the driven wire. In the case of this example, all the wires can be driven simultaneously. Then, when the carriage advances by 1/120 inch, all the wires can be driven again. Timing 2 in FIG. 6 explains this state. Further, every time the carriage advances by 1/120 inch, printing of all wires is repeated, and printing of one line is performed.

It should be noted that the present invention is not limited to the above embodiment, and various modifications are possible based on the gist of the present invention.
They are not excluded from the scope of the present invention.

(Effects of the Invention) As described in detail above, according to the present invention, the serial printer performs printing at a plurality of dot densities.

Then, a plurality of printing elements arranged on a plurality of printing element rows set at a fixed interval and a drive signal for independently driving each of the printing elements in accordance with print data are supplied. Means for dividing the plurality of printing element arrays into a plurality of groups and providing a common drive signal to printing elements on each printing element array in each group.

Further, the density in the horizontal direction of the printing elements on the different printing element rows in the group is set to the density of the least common multiple of the dot densities.

In this case, the printing elements on each printing element row in each group are simultaneously driven by the two driving signals, so that it is possible to suppress the generation of noise and to configure the driving circuit that supplies the driving signals. It can be simplified.

Further, since the horizontal density of the printing elements on the different printing element rows in the group is set to the density of the least common multiple of the plurality of dot densities, the printing elements are moved according to the two drive signals while moving the carriage. , Printing can be performed at various dot densities.

[Brief description of the drawings]

FIG. 1 is a diagram showing a wire arrangement of a multi-row wire head in a serial impact printer of the present invention, FIG. 2 is a block diagram of a serial impact printer to which the multi-row wire head of the present invention is applied, and FIG. FIG. 4 is a signal waveform diagram of a multi-row wire head in the serial impact printer of FIG. 4, FIG. 4 is a timing chart of printing by the multi-row wire head in the serial impact printer of the present invention, and FIG. FIG. 6 is a signal waveform diagram of the multi-row wire head when used, FIG. 6 is a print timing diagram by the multi-row wire head when the serial impact printer of the present invention is used in another print mode, and FIG. 7 is a conventional serial impact printer. FIG. 8 shows a wire arrangement of a multi-row wire head in a printer, and FIG. FIG. 9 is a timing diagram of printing using a conventional multi-row wire head, FIG. 9 is a drive circuit diagram of a multi-row wire head in a conventional serial impact printer, FIG. 9 (A) is a drive circuit diagram of an odd-numbered wire, and FIG. ) Is a drive circuit diagram for even-numbered wires, and FIG. 10 is a print timing diagram when printing is performed at 120 DPI with the multi-row wire head having the wire arrangement shown in FIG. 31… CPU, 32… ROM, 33… RAM, 35… Bus, 37… Space motor, 38… Line feed motor, 39… Print head, 41… Space motor drive circuit, 42… Line feed motor drive circuit, 43… Print head drive circuit.

Claims (1)

(57) [Claims] 1. A serial printer which performs printing at a plurality of dot densities: (a) a plurality of printing elements arranged on a plurality of printing element rows set at a constant interval; Means for supplying a drive signal for independently driving each print element in accordance with print data; and (c) dividing the plurality of print element rows into a plurality of groups, Means for supplying a common drive signal to the print elements of (d), (d) the density of the print elements on different print element rows in the group in the horizontal direction is set to the least common multiple of the plurality of dot densities. A serial printer.