JPH04348967A - Adjustment processing method for head space - Google Patents

Abstract

PURPOSE:To perform adjustment for a slip quantity between heads automatically for a multi-head type printer. CONSTITUTION:'Slip' at a joint part of plural heads 9, is obtained, based on the actual print result, and an adjustment processing unit 2, which sets data for the delay of standard column pulse and print starting position in storages 4, 5, is provided, and it is constituted in such a manner that a head control unit 3 performs printing, conforming to the data.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head-to-head adjustment processing method, and more particularly to a head-to-head adjustment processing method at a joint portion of heads in a multi-head printer.

A multi-head printer has a plurality of heads (eg, a dot matrix print head). Then, each of the plurality of heads prints a printing area in which one line (one line) is divided into a plurality of parts. Therefore, there is always a boundary between each printing area (a joint between the heads).

0003

2. Description of the Related Art In a multi-head printer, "misalignment" may occur at the joint between the heads. If this ``misalignment'' occurs, printed characters will have white streaks (due to the color of the paper), or the characters will be sized in one direction, causing them to become unbalanced. In other words, the quality of printing deteriorates.

[0004] Conventionally, therefore, the following method has been adopted to eliminate this "misalignment." In other words, the head is mechanically fixed to other predetermined parts, but the dimensional accuracy of these heads and other parts is extremely high to prevent "misalignment".
must be indistinguishable by visual inspection. Alternatively, a mechanism for finely adjusting the position of each head is provided, and the amount of "shift" is visually observed based on a specific print pattern, and this is mechanically adjusted.

[0005]

[Problem to be Solved by the Invention] In the above-mentioned prior art, if the method of increasing the dimensional accuracy of parts is used, a considerable number of heads and other parts must be machined with high precision, and each individual part must be machined with high precision. This results in high costs. Further, when attaching the head to other parts, high precision is required for the work, which increases the cost of the mounting work.

On the other hand, if a method is adopted in which a fine adjustment mechanism is provided, the overall cost increases due to the provision of this fine adjustment mechanism. In particular, since a fine adjustment mechanism is required for each head, this cannot be ignored. Furthermore, it is complicated because it involves fine-tuning.

[0007] As described above, the conventional adjustment of the amount of "misalignment" between heads requires high precision or complicated work, and also has the problem of high cost. There was no other way.

An object of the present invention is to provide an inter-head adjustment processing method that automatically adjusts the amount of deviation between heads.

[0009]

[Means for Solving the Problems] FIG. 1 shows a basic configuration diagram of the present invention, and shows a multi-head printer according to the present invention. This printer, as shown in Figure 1(B),
For a line (one line), a head for multiple printing (
(e.g., a dot matrix print head) 9. The plurality of heads 9 print by dividing one line, and there is a boundary part (joint part of the heads) between each printing area. Adjustment of printing at the joint between the plurality of heads 9 is as follows:
This is performed by the adjustment processing section 2.

The plurality of heads 9 constitute a part of the head section 7. The head section 7 is controlled by the head control section 3. A reading sensor 10 is provided near the head 9. The reading sensor 10 constitutes a part of the sensor section 8. The sensor section 8 is controlled by the sensor control section 6.

[0011]

[Operation] The adjustment processing section 2 causes each of the plurality of heads 9 to print a predetermined shape (test pattern) at a predetermined position via the head control section 3. This “predetermined position”
is determined by logically giving the position of the head 9. The adjustment processing unit 2 causes the reading sensor 10 to read the actual position on the printed paper having a predetermined shape via the sensor control unit 6. Then, based on the read actual position and the logically determined predetermined position, data for adjustment at the joint portion is obtained for each head 9, and this data is stored in predetermined storage areas 4 and 5. do. When performing printing, the head control unit 3 controls printing by the plurality of heads 9 using data stored in the storage areas 4 and 5.

According to the above, the "misalignment" at the joint between the plurality of heads 9 can be determined based on the actual printing results, and can be adjusted accordingly. This adjustment processing is then performed by the adjustment processing section 2. Therefore, there is no need for high precision parts or fine adjustment mechanisms, and there is no need for high precision installation or fine adjustment work.

[0013]

[Embodiment] In FIG. 1, a processing device 1 controls the entire printer, and is a CPU (central processing unit).
It consists of memory, etc. The storage areas 4 and 5 are areas managed (held) by the head control unit 3. In the storage area 4, the starting position of printing by the head 9 is stored for each head 9, and in the storage area 5, the print start position of the head 9 is stored. A timer value for correcting the timing of printing according to 9 is stored.

FIG. 2 is a block diagram of an embodiment, showing the hardware block configuration of the printer shown in FIG. CPU1
1, data storage RAM (read/write memory) 12,
Program storage ROM (read-only memory) 13, input port 14, output port 15, and address decoder 16
The processing device 1 is configured by: The head 9 and the hammer driver 17 constitute the head section 7 . A sensor unit 8 is configured by the reading sensor 10 and the sensor driver 19.

In the processing device 1, the program storage RO
The M13 includes programs for performing adjustment processing, head control, and sensor control, and these and the CPU 11 constitute an adjustment processing section 2, a head control section 3, and a sensor control section 6, respectively. The storage areas 4 and 5 are predetermined areas of the data storage RAM 12. A read signal from the sensor driver 19 is input to the input port 14 . The reading sensor 10 has, for example, an A/D converter, and converts the read analog signal into a digital signal. The input port 14 constitutes a part of the sensor control section 6. The output port 15 sends a control signal for printing to the hammer driver 17. This print control signal is generated by the head control section 3 based on the data in the storage areas 4 and 5. The output port 15 constitutes a part of the head control section 3.

In the head section 7, a hammer driver 17
The head 9 is struck by a hammer at a predetermined timing in accordance with a print control signal from the output port 15. The head 9 is attached to a carrier driven by a carrier motor 20. Carrier motor 20 is driven by a motor driver 18 that is controlled by a signal from output port 15 . Note that the motor driver 18 also drives various motors 21 other than the carrier motor 20. In the sensor section 8 , a sensor driver 19 sends the outputs of the plurality of reading sensors 10 and various other sensors 22 to the input port 14 .

FIG. 3 shows the control of printing of a predetermined shape at a predetermined position by the adjustment processing unit 2. Now, as shown,
On a single form (single sheet) 23, one line (one line)
Assume that the width of each line (line) is 2778 columns (dots), and three heads A to C are responsible for printing. The boundary (joint part) of each printing area is correctly 72
6 columns and 1452 columns. In this case, head A prints vertical ruled lines ``■'', head B prints vertical ruled lines ``■'' and ``■'', and head C prints vertical ruled lines ``■''. The position of each print is located 4 columns (n=4) away from the column of the joint portion.

In this case, the interval between the vertical ruled lines ``■'' and ``■'' is used to determine the amount of deviation between the heads A and B. That is, this interval should be detected as 8 columns if there is no mounting misalignment between heads A and B. Vertical ruled lines (■) and (2) are used to determine the amount of deviation between heads B and C. The portions where the vertical ruled lines ■ and ■ and ■ and ■ are printed are read by the reading sensor 10 .

Note that a plurality of reading sensors 10 are provided corresponding to the heads 9, as shown in FIG. 1(B). In this case, the sensor B corresponding to the head B is used to read the vertical ruled lines ``■'' and ``■'', and the sensor C corresponding to the head C is used to read the vertical ruled lines ``■'' and ``■''.

Further, the reason why vertical ruled lines are used as the test pattern is to improve the accuracy when reading by the reading sensor 10 later.

FIG. 4 shows reading by the reading sensor 10. The sensor control unit 6 (input port 14) takes in the output of the reading sensor 10 at the timings shown in the figure from ■ to ■ according to the instructions from the adjustment processing unit 2, and stores it in a predetermined area of the data storage RAM 12 (data buffer). ).

The reference column pulse is supplied from the CPU 11 for each reference column interrupt. The time interval between the reference column pulses corresponds to one column (one dot) on the paper in terms of distance, and specifically is 1/160 inch. Therefore, when a vertical ruled line is read by the reading sensor 10, its output value changes as shown in the figure between the two reference column pulses. Therefore, by finding the peak point of the change and finding the distance between the peak points, the distance is determined, for example, between the vertical ruled lines (■) and (2).

Here, the reading by the reading sensor 10 is performed seven times from (1) to (2) for each reference column pulse. This improves the accuracy of reading vertical ruled lines, that is, peak points. In this case, the position of the vertical ruled line can be determined with an accuracy (resolution) of 1/8 column. Therefore, a deviation in the mounting position of the head 9 can be detected with an accuracy of 1/(160×8) inch.

[0024] If the distance between the peak points of vertical ruled lines ■ and ■ is d1 (column), then the amount of deviation between heads A and B is expressed as 8-d1=c1+c2/8 (c1 and c2 are Integer, c2 is 1 to 7). If 8>d1, this indicates that the mounting interval between heads A and B has become narrower than the standard (correct value). If 8<d1, this indicates that the mounting interval between heads A and B has become wider than the standard.

Similarly, if the distance between the peak points of vertical ruled lines ■ and ■ is d2 (column), the amount of deviation between heads B and C is expressed as 8-d2=c3+c4/8 (c3 , c4 is an integer, c4 is 1 to 7). It is also possible to determine whether the interval is narrower or wider than the standard.

Such reading is performed by the sensor control section 8 in response to an instruction from the adjustment processing section 2 to the sensor control section 8. The sensor control unit 8 reads the data a predetermined number of times at predetermined intervals (7 times in this example, but it may be 15 times, for example) in synchronization with the reference column pulse, and stores the read values in the data buffer. Store in. The adjustment processing unit 2 compares the values of the data stored in the data buffer, finds the maximum value, and sets this as the peak point. In this example,
Four peak points are obtained, and their order is predetermined. Therefore, d1 and d2 and c1 to c4 can be found.

FIG. 5 shows the concept of head-to-head adjustment. Originally, each head A, B, and C would print each dot in synchronization with the reference column pulse, but printing is performed with a shift from the reference column pulse by the amount of "shift". Furthermore, since there are three heads, the center head B is used as the reference, and its deviation amount is always set to "0". The same applies if the number of heads 9 is an odd number. If the number is even, one of the heads 9 from the center is used as the reference.

As shown in FIG. 5, since there is no deviation, head B performs printing in synchronization with the reference column pulse. Head A is shifted from head B by c1+c2/8 columns. The deviation "c2/8" which is less than one column is corrected by delaying the reference column pulse. That is, the reference column pulse is delayed by a time corresponding to the "c2/8" column by the delay timer. The deviation of integer values exceeding one column “c
1'' is corrected by moving the print start position, that is, the print start timing. For example, the timing at which head A prints in synchronization with the 0th reference column pulse is
The timing is set to be synchronized with the "0+c1"th reference column pulse. As a result of the above, head A can perform printing without deviation in synchronization with the print pulse for head A. Similarly, for head C, the deviation from head B is “c3+
c4/8”, “c4/8” becomes “c3/8” due to delay.
” are each corrected depending on the print start position.

[0029] Here, the values "c1", "c2/8", "c
3" and "c4/8" are determined by the adjustment processing unit 2, and the printing start positions c1 and c3 are stored in the storage area 4 as c2/8, which is a timer value for correcting the reference column pulse.
and c4/8 are stored in the storage area 5 in a format corresponding to each head. The head control section 3 refers to these values and controls the head section 7 to perform printing.

FIG. 6 shows a printing time chart. The reference head B starts printing from the "0" pulse in synchronization with the reference column pulse.

Head A prints in the forward direction (direction in the order in which characters line up in one line) with 8<d1, and 8>
In the case of reverse printing (in the opposite direction to the order in which characters are lined up) with d1, printing is performed in synchronization with a pulse delayed by c2/8 columns from the reference column pulse, and the printing start position is set to the delayed "
The pulse is delayed by "c1" from the "0"-th pulse. On the other hand, if 8<d1 and printing in the reverse direction, and 8>d1
When printing in the forward direction, the opposite of the above case (sign of deviation,
In other words, whether it is narrower or wider than the standard is the opposite). Therefore, the pulse is delayed by (8-c2)/8. This is c
It is equivalent to advancing by 2/8. Further, the printing start position is set to a pulse advanced by "c1" times. This head A
The head control unit 3 forms the print pulses for the print head.

Head C has a relationship with head B that is opposite to that of head A. Therefore, the pulse is advanced in the case of forward direction printing when 8<d2 and in the case of reverse direction printing when 8>d2, and in the case of reverse direction printing when 8<d2 and 8>d2
The pulse is delayed when printing in the forward direction.

FIG. 7 is a flowchart of the head-to-head adjustment process. In step 1, paper is sucked from the hopper and set in a predetermined position. In step 2, vertical ruled lines ``■'' to ``■'' are printed on the paper according to instructions from the adjustment processing section 2. In step 3, vertical ruled lines ``■'' to ``■'' are read. The above is as shown in FIGS. 3 and 4. In step 4, the adjustment processing unit 2 determines the peak point (Fig. 4
reference). In step 5, the adjustment processing unit 2
2, and from this the deviation amount c1 + c2/8, c3 + c3
Find /8. In step 6, the adjustment processing section 2 sets data for adjusting the amount of deviation in the storage areas 4 and 5 according to the case classification shown in FIG. In step 7, it is checked whether the amount of deviation is "0". If it is "0", the adjustment process ends. In the subsequent printing process, the head control unit 3 performs printing by referring to the data in the storage areas 4 and 5, so that printing without deviation is possible. If it is not "0", a new line is inserted in step 8, and steps 2 and subsequent steps are repeated. The printing of the vertical ruled lines ``■'' to ``■'' in step 2 is performed using the data in the storage areas 4 and 5. Therefore, in the subsequent step 7, the amount of deviation is set to "0".

[0034]

[Effect of the invention] As explained above, according to the present invention,
In the head-to-head adjustment process for the misalignment at the joint of heads in a multi-head printer, by providing the adjustment processing section 2, the amount of misalignment can be calculated based on the actual printing results. The adjustment process can be performed to eliminate the problem, eliminating the need for high precision parts and fine adjustment mechanisms, and eliminating the need for high precision installation and fine adjustment.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the principle configuration of the present invention.

FIG. 2 is a configuration diagram of an embodiment.

FIG. 3 is an explanatory diagram of printing vertical ruled lines.

FIG. 4 is an explanatory diagram of reading vertical ruled lines.

FIG. 5 is a conceptual diagram of inter-head adjustment.

FIG. 6 is a printing time chart.

FIG. 7 is a flowchart of inter-head adjustment processing.

[Explanation of symbols]

1 Processing equipment 2 Adjustment processing section 3 Head control section 4. Storage area 5. Storage area 6 Sensor control section 7 Head part 8 Sensor part 9 Head 10 Reading sensor 11 CPU 12 Data storage RAM 13 Program storage ROM 14 Input port 15 Output port 16 Address decoder 17 Hammer driver 18 Motor driver 19 Sensor driver 20 Carrier motor 21 Various motors 22 Various sensors 23 single ticket

Claims (3)

[Claims] 1. A head section (7) having a plurality of print heads (9) for one line, a head control section (3) for controlling the head section, and a sensor section (8) having a reading sensor (10). ) and a sensor control unit (6
), an adjustment processing unit (2) is provided that performs adjustment at the joint portion of the plurality of heads (9), and the adjustment processing unit (2) is configured to control the head control unit (3). causes each of the plurality of heads (9) to print a predetermined shape at a predetermined position via the sensor controller (6), causes the reading sensor (10) to read the position of the shape, Data for the adjustment is sent to the head (9) based on the predetermined position and the read position.
), the data is stored in a predetermined area (4, 5), and the head control unit (3) uses the data to control printing by the plurality of heads (9). Adjustment processing method between heads. 2. The inter-head adjustment processing method according to claim 1, wherein the reading sensor (10) reads the position of the predetermined shape a plurality of times for each reference column pulse. 3. The head-to-head adjustment processing method according to claim 1, wherein the data includes a start position of printing by the head (9) and a timer value for correcting a reference column pulse.