JPS6142633B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a serial dot printer.

Dot printers can be roughly divided into serial type and line type. The former is also called the sequential method, in which the print head moves relative to the print medium and prints one character at a time in the process, while the latter prints approximately one print line without moving the print head. They are printed at the same time.

In addition, dot printers can be distinguished from other aspects such as a thermal type using heat, an ink type using ink droplets, a wire type using a printing wire, and a discharge destruction type using electricity.

These dot printers express characters (kanji, numbers, katakana, hiragana, alphabet, etc.) or symbols (hereinafter referred to as "characters, etc.") by a set of dots arranged in a matrix of m dots vertically and n horizontally.

The following explanation will be given using a wire type serial dot printer as an example, but as mentioned above, the present invention can also be applied to thermal type, ink type, etc.

FIG. 1 shows an overall schematic diagram of a serial type wire dot printer.

A platen 2 is rotatably supported on the frame 1, and a carrier guide 3 and a feed screw 4 are arranged in parallel thereto. A carrier 5 is supported by the feed screw 4 and guided by a carrier guide 3. A print head 6 is mounted on the carrier 5, and the print head includes a plurality of print wires and a magnet that pairs with the print wires and impacts the print wires toward the platen 2. The carrier 5 is moved parallel to the surface of the platen 2 by the space motor 7 via the feed screw 4. This movement is called space movement, and in the process of this space movement, the print head 6 drives the print wire in synchronization with the movement.
The print medium 9 is transferred to the platen 2 via the ink ribbon 8.
to press. As a result, dots are formed, and characters, etc. are expressed by a collection of dots.

Now, as the scope of use of such wire dot printers has expanded, it has become possible to print not only characters with a small number of strokes such as alphanumeric characters, but also complex characters with a large number of strokes such as kanji. There has been a demand for a printer that can do this.

In this way, compared to alphanumeric characters, kanji characters are more complex, and therefore, compared to alphanumeric characters, kanji characters are difficult to read unless the dot spacing is small and the characters are printed in a dense collection of dots. Therefore, alphanumeric characters, etc. may be printed as a set of low-density dots, and kanji characters, etc., may be printed and expressed as a set of high-density dots.

On the other hand, the printing speed of a dot printer is determined by the dot spacing, that is, the dot density. That is,
If the period of the magnet that drives the print wire is constant, the print head can be moved at high speed when the dot density is low, but when printing characters etc. with high dot density, the print head must be moved at low speed. It won't happen.

Therefore, when printing a text containing a mixture of alphanumeric characters, etc. and kanji, etc., it is conceivable to limit the movement speed of the printing head to a low speed that is sufficient to print kanji, etc.; however, it is possible to print kanji, etc. It is undesirable that the overall printing speed decreases due to this.

Therefore, the applicant of this application moves the printing head at high speed when the characters to be printed are a collection of low-density dots, such as alphanumeric characters, etc. The present invention provides a dot printer in which the print head is moved at a low speed when printing characters or the like using a collection of high-density dots.

However, according to this method, when printing alphanumeric characters after Chinese characters, or when printing Chinese characters after alphanumeric characters, the moving speed of the print head must be changed each time. Therefore, the space drive control system for controlling the movement of the print head is complicated.

The present invention has been made to eliminate such drawbacks, and a dot printer control device according to the present invention will be explained below with reference to the drawings.

FIG. 2 shows a block diagram of a control circuit for a wire dot printer showing one example of the present invention.

LB is a line buffer that stores characters to be printed in a pattern. Its storage capacity corresponds to one print line of the print medium. MB is a mode buffer, and the characters stored in the line buffer LB are characters specified to be printed in a set of high-density dots (hereinafter referred to as kanji mode), or are characters etc. that are specified to be printed in a set of high-density dots, or are printed in a set of low-density dots. Whether the characters are designated to be printed as a set (hereinafter referred to as alphanumeric mode) is represented by binary values (logical signals "1" and "0"). Now, let us say that characters designated in kanji mode are represented by "1", and characters designated in alphanumeric mode are represented by "0".

The ADC is an address counter and sends a step pulse to the line buffer LB and mode buffer MB every time a dot pulse is input.

Address counter ADC in line buffer LB
When a signal is input from , a pattern of one vertical line of one character is sent to the pattern register PRG. Similarly, the mode buffer MB uses a mode determination circuit depending on whether the pattern sent from the line buffer LB to the pattern register PRG is designated as kanji mode or alphanumeric mode.
Send “1” or “0” to MJ.

MOC is a motor control circuit, and the output of the mode determination circuit MJ is input to this motor control circuit MOC. The motor control circuit MOC instructs the motor drive circuit MOD to drive at a low speed if the output of the mode determination circuit MJ is the kanji mode, and instructs the motor drive circuit MOD to drive at a high speed if the output is the alphanumeric mode.

Motor drive circuit MOD is motor control circuit
Space motor 7 based on instructions from MOC
Rotate.

DPG is a dot pulse generator, which generates dot pulses corresponding to the rotation of the space motor 7, that is, the position of the print head 6, and sends them to the address counter ADC and the magnet control circuit MC.

The input of the dot pulse to the address counter ADC has been described above, but when the dot pulse DP is input to the magnetic control circuit MC, a print signal is given to the magnetic drive circuit MD with a certain delay. With magnetic drive circuit MD
According to the contents stored in the PRG, only the selected magnet out of the plurality of magnets is energized and the corresponding printing wire is impacted, thereby forming a dot row on the printing medium according to the contents of the pattern register PRG. be done.

MCD is a mode change detection circuit, and only when the character to be printed now is in kanji mode and the character to be printed next is in alphanumeric mode, it is detected by information lines l and l-1. Detect. When this mode change detection circuit MCD detects the above state, it sends a verification signal to the mode detection circuit MDD.

When the verification signal is input to the mode detection circuit MDD, it detects in which mode the top two characters to be printed next are specified, using the information lines l-1 and l-2. In the mode detection circuit MDD, the upper two characters etc. are in alphanumeric mode, that is, information lines l-1, l-
A mode conversion signal is sent to the motor control circuit MOC only when the signal No. 2 is not "0" or "0".

In the motor control circuit MOC, when a mode conversion signal is input, the mode of one character, etc. immediately after changing from kanji mode to alphanumeric mode (this is alphanumeric mode) is forcibly set to kanji mode, and the motor drive circuit Commands the MOD to drive at low speed.

Also, the information line l when the verification signal arrives
When the signals of -1 and l-2 are "0" and "0", the mode detection circuit MDD is activated by the motor control circuit MOC.
Since no mode conversion signal is sent to the space motor 7, the space motor 7 is rotated in accordance with the mode given by the mode buffer MB.

This will be explained based on FIG.

In Figure 3, a is the text to be printed,
Kanji and hiragana are mixed. Therefore, if we set kanji to kanji mode and hiragana to alphanumeric mode, kanji becomes 1, as shown in figure b.
Since hiragana is designated by "0", according to the proposal by the applicant mentioned at the beginning, kanji are printed at low speed and hiragana are printed at high speed, as shown in c of the same figure.

On the other hand, according to the present invention, if the number of consecutive characters specified in the alphanumeric mode immediately after a character specified in the kanji mode is less than 2, the mode specification is ignored and the characters are forcibly displayed. Converts the mode as specified by Kanji mode.

Furthermore, if the number is 2 or more, the original mode designation is adopted.

Therefore, the speed of the space motor 7 is as shown in d in the same figure, and only "Ete" is printed at high speed.

FIG. 4 shows another example according to the present invention. The difference from the example explained in FIG. 2 is that the example in FIG. 2 judges whether or not to change the speed during printing. On the other hand, the method described below performs mode conversion before being stored in the mode buffer.

In FIG. 4, the transmitted patterns such as characters are stored as they are in the line buffer LB. On the other hand, the mode information paired with this character pattern is sent to the mode judgment circuit MJ ₂ and the mode conversion circuit.
Entered into MCC. The mode determination circuit MJ ₂ performs counter control via the information line l ₃ when the incoming mode information is the kanji mode, that is, "1", and via the information line l ₄ when it is the alphanumeric mode, that is, "0". Send a signal to the circuit CNTC. The counter control circuit CNTC sends a signal to the count terminal CNTT to count the number of "0"s when it arrives from the mode determination circuit _MJ2 , and the mode determination circuit
When "1" arrives from _MJ2 , a signal is sent to the reset terminal R to reset the contents of the counter CNT.

Therefore, the counter CNT counts the number of consecutive "0"s in the mode information, and is reset when "1" arrives. If the count value of the counter CNT is less than 2, the overflow pulse is sent to the mode conversion circuit MCC.
Send to. In the mode conversion circuit MCC, when an overflow pulse is input, the counter control circuit
Based on a mode switching detection signal sent from the CNTC indicating a change from kanji mode to alphanumeric mode, the alphanumeric mode which is the mode immediately after that signal is forcibly converted to kanji mode. Further, when no overflow pulse arrives from the counter CNT, the mode information directly input to the mode conversion circuit MCC is given to the mode buffer MB, and only in the above case, the mode is converted and given to the mode buffer MB.

Note that the other circuits in FIG. 3 are the same as the circuits in FIG. 1, and are given the same reference numerals.

FIG. 5 shows an aspect of mode conversion in FIG. 4, and FIG. 5 a shows mode information input to the mode determination circuit MJ, and b shows mode information stored in the mode buffer MB.

As described above, in the present invention, when the number of consecutive characters etc. to be printed at high speed is less than a predetermined number, the print head is forcibly moved at low speed, and the characters that should be printed at high speed are left at the same low speed. Since the printing is performed at the same speed, there is no speed change time that occurs when the speed is changed, and printing can be performed efficiently.The number of times the speed must be changed is reduced, so the control is also simplified.

In addition, in Figures 1 and 2, the boundary value is less than 2 consecutive numbers, but it may be less than n depending on the speed ratio at high speed and low speed, speed fluctuation time when changing speed, etc. Of course.

[Brief explanation of the drawing]

FIG. 1 shows a control circuit for a dot printer according to the present invention in block form. Figure 2a shows an example of a text to be printed, Figure 2b shows its mode information, Figure 2c generally shows the speed of the printhead according to the proposed technique, and Figure 2d shows the speed of the printhead according to the present invention. Show change. FIG. 3 shows another example of a dot printer control circuit in block form. FIG. 4a shows mode information before conversion, and FIG. 4b shows mode information after conversion. FIG. 5 shows an example of mode conversion in FIG. 4. In the figure, 2 is a platen, 6 is a print head, 7 is a space motor, a is a print medium, MJ, MJ ₂ is a mode determination circuit, LB is a line buffer, MB is a mode buffer, MCD is a mode change detection circuit, and MDD is a mode detection circuit. circuit, CNTC is a counter control circuit,
CNT is a counter, MCC is a mode conversion circuit, CON
indicate the motor control circuit, respectively.

Claims (1)

[Scope of Claims] 1. In the process in which a print head having a plurality of printing elements arranged along the transport direction of printing paper moves in a direction perpendicular to the transport direction, the printing elements are selectively driven. In a serial printer that forms dots and prints one line of characters continuously, and then feeds the printing paper in the transport direction, there is a buffer in which print information indicating the characters to be printed is sequentially stored, and this buffer a determining means for determining whether the dot density of characters or the like indicated by each stored print information is high or low; a means for specifying a moving speed of the print head in the digit direction based on the determination result of the determining means; means for detecting the number of consecutive pieces of printed information with a low dot density among each piece of printed information written in the print head; A control device for a dot printer, characterized in that the continuous print information group with low dot density is printed by moving in the digit direction at a moving speed corresponding to the print information with high dot density.