JPH0747713A - Serial printer - Google Patents

Abstract

PURPOSE:To print the pattern of a correction printing example for accurately selecting the optimum correction value by providing a correction pattern printing means printing the pattern of the correction printing example in the printing timing made to lag by a printing timing correction means. CONSTITUTION:An encoder pulse count circuit 4 is connected to a timer circuit 5 and constituted of the encoder connected to the rotary shaft of a carrier motor 13. The number of pulses after a printing head 8 (carrier) starts scanning is counted on the basis of the encoder pulses generated from the encoder by the rotation of the carrier motor 13 and the count value is outputted to the timer circuit 5. A printing timing correction means is constituted of the encoder pulse count circuit 4 and the timer circuit 5. The timer circuit 5 compares the count value outputted from the encoder pulse count circuit 4 with the correction value (delay time) set by a CPU 1 and, at the point of time when both values coincide with each other, the timer circuit 5 outputs printing start timing to the CPU 1 or a head driving circuit 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a serial printer which prints on a sheet by reciprocally scanning a print head in a direction orthogonal to the sheet conveying direction.

[0002]

2. Description of the Related Art In a thermal printer, a wire dot printer, an ink jet printer or the like, a print head is mounted on a carrier, and the carrier is scanned in a direction orthogonal to the paper conveyance direction, and the print head is scanned with the carrier. A serial printer that prints on paper is known.

Further, even in such a serial printer, in order to speed up the printing process, in the reciprocal scanning of the carrier, the paper is conveyed by one line after printing one line by the forward scan and before the backward scan. It is known that one line is printed by a backward scan.

However, there is a problem with the accuracy of the carrier scanning mechanism, and there is a risk of printing deviation between the forward scan and the backward scan. Then, for example, when printing a continuous image without line separation such as graphics, the graphics are misaligned. Also, in the case of characters and the like, in the case of enlarged characters and characters that extend over two lines, there is a gap at the boundary between forward and backward.

In order to solve such a problem, conventionally,
It is known that the printing timings in the forward scanning and the backward scanning are shifted to correct the deviation of the graphic or image in the printing in the forward scanning and the printing in the backward scanning.

As a method of correcting this deviation, the print control signal to the print head is delayed by a delay value (delay value) corresponding to the correction value, and the print timing is adjusted.
A method of correcting a deviation in printing is known.

Conventionally, in order to determine the correction value of this method, first, test printing is performed at standard printing timing, the delay value is estimated from this test printing, and the delay value is set as the correction value. The test printing is performed again with the delay value thus set, and the quality is judged. If it is judged by this judgment that the deviation still occurs, it is necessary to set the delay value again, perform test printing, and repeat the above work until the optimum delay value is obtained. Met.

In such a method, there is a problem that the work for determining the delay value becomes complicated and takes time. In response to such problems,
The ones described in Japanese Patent Application Laid-Open No. 62-109657 and Japanese Patent Application Laid-Open No. 62-109657 have been proposed.

The method disclosed in Japanese Utility Model Publication No. 3-8448 is one in which a pattern of a correction printing example using a plurality of correction values is printed in one line (one reciprocation). You can select and set the value.

Further, the one disclosed in Japanese Patent Laid-Open No. 62-109657 discloses one delay value for one delay value.
Reciprocal printing is performed for each dot or multiple dots, and 1
A test pattern is printed on a line, the test pattern is assigned to each of a plurality of set delay values for each line, and the test pattern is printed.

[0011]

[Problems to be Solved by the Invention]
The one described in Japanese Patent No. 448 prints the pattern of the correction printing example with a plurality of correction values in one line, so it does not matter if the scanning of the print head by the carrier is always constant in one line. , For example, if the carrier vibrates slightly at both ends of the scan due to problems with the drive mechanism,
The correction print pattern of the correction value printed on both ends of one line is
As a result of being affected by this minute vibration, the correction print pattern of each correction value is not printed with equal accuracy, and how the correction print pattern of one correction value is printed in the entire scanning range. There is a problem that the correction value cannot always be selected accurately because it is unknown.

The method disclosed in Japanese Patent Laid-Open No. 62-109657 prints a test pattern on a plurality of lines for all the set correction values. Therefore, when there are many correction values, There is a problem that all the test patterns cannot be printed on one sheet and the number of correction values that can be set is limited.

Therefore, the present invention provides a serial printer which can have a large number of correction values which can be set and which can print a pattern of a correction printing example for easily and accurately selecting an optimum correction value. The purpose is to do.

[0014]

SUMMARY OF THE INVENTION The present invention is a serial printer that prints on a sheet by reciprocally scanning a print head in a direction orthogonal to the sheet conveying direction, and is nonvolatile by storing a plurality of correction values. A memory, a set correction value storage means for storing a set correction value, and a correction value extraction for reading a preset number of correction values before and after the correction value stored in the set correction value storage means from a non-volatile memory. Means, and a print timing correction means for shifting the print timing between forward scan and backward scan of the print head based on the correction value stored in the set correction value storage means or the correction value read by the correction value extraction means, The correction value stored in the set correction value storage means and the preset number of correction values read from the non-volatile memory by the correction value extraction means are used for a plurality of runs on one sheet. Assigned to each row formed by, is provided with a correction pattern printing means for printing a pattern of the correction print example in the printing timings shifted by the respective printing timing correction means.

[0015]

In the present invention having such a configuration, the correction value extraction means reads the preset number of correction values before and after the correction value stored in the set correction value storage means from the non-volatile memory.

The correction pattern printing means forms the correction value stored in the set correction value storage means and the preset number of correction values read by the correction value extraction means by a plurality of scans on one sheet. Assigned to each row,
The pattern of the correction print example is printed at the print timings shifted by the print timing correction means.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing a circuit configuration of essential parts of a serial printer to which the present invention is applied.

Reference numeral 1 denotes a CPU (cent
ral processing unit). A ROM (read only memory) 2 as a non-volatile memory in which program data for processing performed by the CPU 1 is stored, areas of various memories used when the CPU 1 performs processing are formed, and a selected correction value is A RAM (random access memory) 3 as a set correction value storage means to be stored, an encoder pulse count circuit 4, a timer circuit 5, and an I / O (input / input) connected to a host computer via a line.
output) interfaces 6 are connected to the CPU 1 via a system bus 7, respectively.

Further, a head drive circuit 9 and an I / O board 10 which are mounted on a carrier (not shown) and drive a print head 8 for reciprocally scanning in the sheet conveying direction to perform printing on the sheet, are also provided in the system bus. It is connected to the CPU 1 via 11.

The print head 8 has a large number of dot pins or ink discharge ports (not shown) along the paper transport direction.
Are arranged, and a large number of dot pins or ink ejection ports are divided into upper and lower parts and driven.

The ROM 2 further includes a character generator 2a for converting character codes into image data.
And a correction value area 2b in which the correction values of −32 to +32 are stored.

On the I / O board 10, a paper feed motor drive circuit 12 for driving a paper feed motor 11 for carrying a sheet, and a carrier motor drive circuit 14 for driving a carrier motor 13 for carrying a carrier back and forth. Further, an operator panel 15 including a keyboard 15a provided with an end key, a minus (-) key, a plus (+) key and the like is connected.

The encoder pulse counting circuit 4 is
The print head 8 (carrier) is scanned by an encoder pulse that is connected to the timer circuit 5 and is connected to the rotation shaft of the carrier motor 13 and that is generated by the encoder due to the rotation of the carrier motor 13. The number of pulses after the start is counted, and the count value is output to the timer circuit 5.

In the timer circuit 5, the count value output from the encoder pulse count circuit 4 is the C value.
Compare with the correction value (delay time) set by PU1,
When they match, the print start timing is set to C
It is output to the PU 1 or the head drive circuit 9.

Therefore, the encoder pulse count circuit 4 and the timer circuit 5 constitute a print timing correction means.

FIG. 2 shows the flow of the correction value setting process performed by the CPU 1.

First, the paper used for test printing is inhaled.

Next, the currently set correction value stored in the RAM 3 is read, and the correction value is centered on the correction value -2, correction value -1, correction value, correction value +1, correction value +2.
5 correction values are read from the correction value area 2b formed in the ROM 2 (correction value extraction means).

Each of the read correction values is sequentially set in the timer circuit 5, and the print timing is shifted by each correction value, and the forward scan, the backward scan, and the forward scan are performed.
The adjustment pattern (pattern of the correction printing example) of one stage (one line) consisting of scanning is printed, and by all five correction values,
The adjustment pattern is printed in five steps (correction pattern printing means).

When the printing of the five-step adjustment pattern is completed, the current correction value stored in the RAM 3 is printed in the margin below the five-step adjustment pattern on the paper.

Next, as the processing of step 1 (ST1), a state of waiting for key input from the keyboard 15a of the operator panel 15 is entered, and when a key is input from the keyboard 15a, the key input is a key input by the end key, Alternatively, it is determined whether the key input is the minus key or the plus key.

If none of the above key inputs is made, the process returns to the above-mentioned step 1 again.

If the key input is the plus key,
Adds +1 to the currently specified correction value (initial value is the currently set correction value stored in RAM3), and if the key input is by the minus key, the currently specified correction value is added. The subtraction process of -1 is performed to change the correction value, and the process returns to the above-mentioned step 1 again.

If the key input is by the end key, the currently designated correction value is stored in the RAM 3 as the set correction value, and the adjustment pattern of 5 steps is printed.
Eject the paper on which the previously set correction value is printed.

When the discharge of the sheet is completed, the correction value setting process is completed.

In the present embodiment having such a configuration, for example, five-step adjustment patterns as shown in FIG. 3 are printed. In FIG. 3, the correction value that is set is +00 as printed in the lower margin of the five-step adjustment pattern in FIG.

That is, +00 is stored in the RAM 3 as the currently set correction value, and when test printing is performed, the +00 correction value stored in the RAM 3 is read and the +00 correction value is read. Centered at the correction value of ± 2, that is, -02, -01, +00, +01,
Five correction values +02 are read from the correction value area of the ROM 2.

Note that R is the correction value currently set.
If a correction value of +07 is stored in AM3,
Five correction values +05, +06, +07, +08, +09 are read from the correction value area 2b of the ROM 2.

When the five correction values are read from the ROM 2, the read correction values are sequentially set in the timer circuit 5.

First, the correction value of -02 is set in the timer circuit 5, and the encoder pulse count circuit 4 and the timer circuit 5 correspond to the print timing of -02 by the forward scan and the backward scan. The uppermost adjustment pattern in FIG. 3 is printed by the forward scan, the backward scan, and the forward scan. In the printing example of FIG. 3, the correction value of -02 causes a deviation between the forward scan and the backward scan.

FIG. 4 shows an enlarged view of the left side portion A with the correction value of -02. As shown in FIG. 4, about 1 at the upper end
/ 4 is a dot pin divided into two by forward scanning or a printing part by a lower head portion of an ink ejection port, and about ½ of the whole center is all dot pins or ink ejection by backward scanning. It is a printing part by the whole head using the outlet. Then, about 1/4 of the lower end is a printing part by the dot pin divided by the forward scan and the upper head part of the ink ejection port.

Therefore, it is possible to confirm the deviation between the lower end of printing by forward scanning and the upper end of printing by backward scanning, and the deviation between the lower end of printing by backward scanning and the upper end of printing by forward scanning. That is, it is possible to confirm the mutual misalignment due to the reciprocal scanning of the upper head portion and the lower head portion which are divided into two.

Next, the correction value of -01 is set in the timer circuit 4, and the encoder pulse count circuit 4 and the timer circuit 5 correspond to the print timing of printing by forward scanning and printing by backward scanning at -01. After that, the adjustment pattern on the second stage from the top in FIG. 3 is printed by the forward scan, the backward scan, and the forward scan.

Similarly, the correction value of +00, the correction value of +01, and the correction value of +02 are sequentially set in the timer circuit 4, and the encoder pulse count circuit 4 and the timer circuit 5 cause printing by forward scanning and return. The printing timings of the printing by scanning are shifted in correspondence with +00, +01, +02, and the forward scanning, the backward scanning, and the forward scanning result in the third row from the top, the fourth row from the top, and the bottom row in FIG. The adjustment pattern is printed.

Further, "current value = + 0" indicating the current correction value is further displayed in the margin at the bottom of the adjustment pattern at the bottom.
"0" is printed, and this test printing ends.

The operator refers to the printed matter, selects the optimum correction value, changes the correction value with the plus key and the minus key of the keyboard 15a of the operator panel 15, and determines with the end key. It should be noted that the change of the correction value by the plus key and the minus key is not limited to the five correction values shown in the test print, and may be +32 to −32.
Any correction value up to can be selected.

By the key input of the end key, the designated correction value is stored in the RAM 3 as the set correction value. During normal printing, the correction value stored in the RAM 3 is stored in the timer circuit 5. Is set to, and the print timing for printing by forward scanning and printing by backward scanning is R
There is a shift corresponding to the correction value stored in AM3.

Since the numerical value of the correction value is set in the timer circuit 5 and this timer circuit 5 is compared with the count value from the encoder pulse count circuit 4, the actual correction amount of the deviation due to this correction value is Depends on encoder resolution. Therefore, if an encoder with high resolution is used, highly accurate correction can be performed. Moreover, since a large number of correction values can be taken, it is possible to set a wide range in which correction can be performed even if an encoder with high resolution is used.

As described above, according to the present embodiment, the correction value area 2b formed in the ROM 2 and storing a large number of correction values.
And the RAM 3 storing the selected and set correction values, the encoder pulse count circuit 4 and the timer circuit 5 for shifting the print timing between the forward scan printing and the backward scan printing of the print head 8, and the correction values are changed. A keyboard 15a provided on the operation panel 15 for adjusting the correction value −2, the correction value−1, the correction value, the correction value + 1, the correction value +
Five correction values 2 are read from the correction value area 2b, and printed by three scans of forward scan, backward scan, and forward scan 1
The adjustment pattern of the step is printed in five steps with the print timing being shifted by the read five correction values, and the correction value that is currently set is printed underneath, so that the test print is currently set. Before and after the correction value +2 to -2
Print the adjustment pattern for the five correction values between
On the other hand, the correction value to be set is set in the correction value area 2a by the key input of the plus key and the minus key of the keyboard 15a.
Since it can be arbitrarily set within the range of the correction value stored in, a large number of correction values can be stored (registered) in the correction value area 2a formed in the ROM 2.

Therefore, even if the driving mechanism for scanning the carrier deteriorates due to aging, there is a high possibility that the correction value around the currently set correction value can be used for correction.
The optimum correction value can be determined by one test printing. In addition, if the resolution of the encoder is high, the correction amount can be set accurately, and a large number of correction values can be stored, so that the range of the correction amount can be widened and the optimum correction value can be accurately set. An adjustment pattern can be printed for easy selection.

Further, in this embodiment, since one adjustment pattern is printed by three scans of the forward scan, the backward scan and the forward scan with one correction value, the lower end of the print by the forward scan and the reverse scan are printed. It is possible to obtain the effect that not only the deviation from the upper end of printing by scanning but also the deviation between the lower end of printing by backward scanning and the upper end of printing by forward scanning can be checked together.

In this embodiment, the correction value stored in the RAM 3 is centered on the correction value -2 and the correction value-.
The adjustment pattern of five steps was printed for five correction values of 1, correction value, correction value + 1, and correction value + 2, but the present invention is not limited to this.
Steps, 8 steps, 9 steps, etc. may be used, and it is not necessary to completely center the currently set correction value.
5 of 1, correction value, correction value +1, correction value +2, correction value +3
It is also possible to print the adjustment pattern in five stages with the individual correction values.

[0054]

As described above in detail, according to the present invention,
It is possible to provide a serial printer that can have a large number of correction values that can be set and that can print a correction print pattern for easily and accurately selecting an optimum correction value.

[Brief description of drawings]

FIG. 1 is a block diagram showing a circuit configuration of essential parts of an embodiment of the present invention.

FIG. 2 is a diagram showing a flow of a correction value setting process of the embodiment.

FIG. 3 is a diagram showing a printing example of an adjustment pattern of the embodiment.

FIG. 4 is an enlarged view showing a portion A in FIG.

[Explanation of symbols]

1 ... CPU, 2b ... Correction value area, 3 ... RAM, 4 ... Encoder pulse counting circuit, 5 ... Timer circuit, 8 ... Print head, 9 ... Head drive circuit, 13 ... Carrier motor, 15a ... Keyboard.

Claims (1)

[Claims] 1. A serial printer that prints on a sheet by reciprocally scanning a print head in a direction orthogonal to a sheet conveyance direction, a nonvolatile memory storing a plurality of correction values, and a set correction value. Setting correction value storage means for storing a value, correction value extracting means for reading a preset number of correction values before and after the correction value stored in the setting correction value storage means from the non-volatile memory, and the setting correction Print timing correction means for shifting the print timing between forward scan and reverse scan of the print head based on the correction value stored in the value storage means or the correction value read by the correction value extraction means; and the setting correction. A plurality of correction values stored in the value storage means and a preset number of correction values read from the non-volatile memory by the correction value extraction means on a single sheet. And a correction pattern printing unit that prints the pattern of the correction printing example at the printing timing shifted by the printing timing correction unit.