JP3528585B2 - Serial printer and method for determining print timing of serial printer - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to serial printers, and particularly when a pulse motor without an encoder is used as a carriage motor,
The present invention relates to a print timing determination technique for improving print position accuracy in an acceleration / deceleration section of a carriage motor.

[0002]

2. Description of the Related Art In serial printers such as impact dot printers and ink jet printers, acceleration / deceleration printing control is performed to perform printing even during acceleration / deceleration of a carriage motor in order to reduce size and increase speed. Hereinafter, in order not to complicate the description, only the printing during acceleration will be described and described, but those skilled in the art should be able to easily understand that the printing during deceleration is similar.

FIG. 1 shows a basic conceptual diagram of print control during carriage acceleration.

When a print command is applied, parameters required for printing, for example, print timing data (T0, T1, T2, ..., T) that defines print timing for each dot position.
Y, TZ) and print timing correction data for correcting the print timing thereof are loaded into the control circuit. Then, when the carriage motor is activated, the carriage starts traveling and accelerates after the RUSH time before the backlash of the mechanism is first removed. At the same time when the carriage starts running, the print control process starts printing, the print timing data (T0) for the first dot position is set in the timer, and the timer starts time counting. When the timer count reaches the set time (T0), the print interrupt process is performed, the drive signal is given to the print head, and the second dot print timing data (T1).
Is set in the timer. After that, the print interrupt process is repeated at the time intervals equal to the print timing data (T1, T2, ..., TY, TZ) for the second and subsequent dots, and subsequent dots are printed. Then, when the acceleration region ends, the acceleration printing control ends, the constant speed printing control starts, and each dot is shot at a constant time interval.

The print timing data (T0, T1, T2 ... TY, TZ) used in the accelerated print control is stored in the storage device of the printer in the form of a table. The data of this print timing table is determined at the time of design based on the data actually measured by actually moving the carriage. In addition, in the case of a printer that supports multiple different resolutions, different dot resolutions will usually result in different acceleration curves for the carriage as well as different dot resolutions, so a print timing table suitable for each print resolution is prepared. Has been done.

FIG. 2 shows a functional configuration of accelerated printing control of a conventional printer.

The print timing table 1 has 90 dp
A print timing table for each resolution corresponding to a plurality of resolutions such as i and 96 dpi is included. In the print timing table for each resolution, the first data T0 indicates the time from the start of printing to the time when the first dot is printed, and the second and subsequent data T1, T2, ... Are each second and subsequent dots. Is the time interval from the time when the previous dot is hit to the time when the dot is hit, in other words, the time required for the carriage to travel one dot pitch at each resolution. Since the carriage is accelerating, the later print timing data becomes shorter as T1>T2>T3>.

Further, a print timing correction table 3 is prepared, and correction time data for correcting the first print timing T0 for each row is stored therein. The correction time data is as follows. The distance between the current stop position where the carriage is stopped after printing a certain line and the print start position of the next line is different for each line. Therefore, it is necessary to correct the first print timing T0 for each line in consideration of this distance. Further, during printing, due to a time lag from when the drive signal is sent to the head to when the wire arrives at the paper, the overall dot position of each line is displaced from the target dot position. Therefore, it is necessary to correct the first print timing T0 of each line so as to eliminate this misalignment (this correction is hereinafter referred to as "Uni-Direction" in the sense of correcting an error while the carriage is running in one direction (Uni-Direction)). -D correction "). In addition, bidirectional printing (Bi-D
In the irection printing mode, since the dot position deviation appears differently in the forward and backward passes, it is necessary to change the correction amount of the first print timing T0 depending on whether the forward or backward pass (this correction is referred to as "Bi-D correction" below). ")). Therefore, in the print timing correction table 3, for example, correction time data for correcting the first print timing T0 with a fineness of 1/16 of one dot pitch, for example, T1 * 1/16,
T1 * 2/16, ..., T1 + T2 * 1/16, T1 + T
2 * 2/16, ... Are stored. From the table 3, at the start of printing of each row, the print timing correction is performed by selecting appropriate correction time data according to the above circumstances and adding it to the first print timing T0. The addition of the correction time data to the first print timing T0 means that the print timings of all the dots in the row are moved backward by the correction time data.

The print timing determining unit 5 shown in FIG. 2 reads print timing data T0, T1, T2, ... According to the resolution from the print timing table 1, and also prints the print timing data T0, T1, T2, ... The optimum correction time data that takes into account the carriage stop position, the next print start position, Uni-D correction, and Bi-D correction are read. The print timing data T0, T
The print timing of each dot position in the row is determined from 1, T2, ... And the correction time data, and is given to the head control circuit 7. The head control circuit 7 gives a drive signal to the head 9 through the head drive circuit 8 at the determined printing timing of each dot.

[0010]

As described above, the correction of the first print timing T0 using the correction time data means that the print timings of all the dots in the row are moved backward by the correction time data. Means that. When each print timing is moved backward by the correction time data,
The carriage speed at each print timing after the correction is faster than that before the correction by the increase in the speed of the carriage accelerated during the correction time data. In order to increase this speed, the carriage speed before correction is used as a reference 2
It is not possible to simply use the print timing data T1, T2, ... After the dot as it is.

A specific example will be described. It is assumed that the same value as the second print timing data T1 is selected as the correction time data. Then, the print timings of all the dots are shifted by T1. That is, by this correction, the time at which the first dot is printed is shifted to the time T0 + T1 at which the second dot should be printed before the correction. Therefore, in this case, as the print timing data for the next second dot, it is more appropriate to use T2 for the third dot instead of the data T1 for the second dot on the print timing table 1. It turns out that.

Although the above example is the simplest case, in reality, the correction time data is, for example, T1 / 16, T
In most cases, it is an intermediate value such as 1/8 and T1 + T2 / 4, which does not exactly match the print timing data (T1, T2, ...). When such intermediate correction time data is selected, the conventional accelerated printing control is performed as shown in FIG.
As shown in FIG. 3, the print timing data T1, T2, ... In the print timing table 1 is shifted by the correction time data α, and the print timing is closest to the print timing (for example, in the example of FIG. 3, T1 or T2 for the second dot and T2 or T for the third dot
3) is selected and the data is used as it is. However, with this conventional control, the accuracy of the print position control is not very high.

Therefore, it is an object of the present invention to realize more accurate print position control during an acceleration / deceleration section.

[0014]

According to the printer of the present invention, when the print timing of the first dot of a line is determined and then the print timing of the second and subsequent dots is determined, it is determined by the following method. To do. That is, the acceleration section of the carriage is virtually divided into many small sections. This small section is extremely short such that a plurality of (N) continuous small sections are combined to form a one-dot pitch. That is, each small section is obtained by dividing each dot pitch by N. Then, prepare time data indicating the time that the carriage travels in each of these small sections, and from these time data, a set of time data after the small section corresponding to the print timing of the first dot, A large number of sets are selected with one set of continuous N time data. Then, by adding N pieces of time data of each selected set, the print timing of each dot after the second row of the row is determined. By this method, when the first print timing is corrected for a certain time, the increase in the speed of the carriage at that time is 2
Since the print timings of the dots after the first dot are reflected in detail, the precision of the print position control becomes higher than in the conventional case.

In a preferred embodiment, the time data of the large number of small sections are recorded in a storage device in the form of a table, and the N time data of each set are read out from the table, The print timing of each dot is determined by adding N times. In another embodiment, the calculated addition value of each set of time data is recorded in a storage device in the form of a table, and each time data addition value is read from this table to print each dot. I try to decide the timing. In the latter case, it is necessary to prepare N tables with different combinations of N time data.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Some embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 4 shows the first of the present invention.
4 is a block diagram of accelerated printing control of the embodiment of FIG.

The print timing table 11 is, for example, a print timing table having a resolution of 90 dpi,
A print timing table with a resolution of 96 dpi is prepared. In the print timing table for each resolution, N pieces of each dot pitch (N> 2) are provided following the print timing data T0 indicating the time from the start of printing to the first dot.
The carriage running time of each small section is registered.

In the example of FIG. 4, each dot pitch is divided into four small sections and the time data of these four small sections are registered in the print timing table with a resolution of 90 dpi. That is, the time section of the print timing data T1 for the second dot of the related art shown in FIG. 1 is divided into four small section time data T11, T12, T13, and T14. Similarly, the time interval of the print timing data T2 for the third dot of the prior art is also divided into time data T21, T22, T23, T24 of four small intervals, and the same applies to the subsequent T3, T4 ,. is there. Since each dot pitch is 1/90 inch, the time data of one small section corresponds to 4/1440 inch.

Similarly, in the case of a print timing table having a resolution of 96 dpi, each dot pitch (1/96 inch) is divided into 5 sections (3/1440 inch).
That is, the print timing data T1 for the second dot of the prior art is set to T11, T12, T13, T14, T15.
Are divided into time data of five small sections, and the subsequent print timing data T2, T3, ... Are similarly divided into five time data.

By the way, the time data T11 of each small section,
Several methods can be used to determine T12, T13, T14, .... The most laborious but most accurate method is
This is a method of actually traveling the carriage and measuring the traveling time of each small section. On the contrary, the simplest method, which is less accurate, is a method of dividing the time interval of the print timing data T1, T2, ... In this method, N pieces of time data in the time section of the same print timing data are equal to each other, so that only one of the time data needs to be stored, and the storage capacity can be saved. Become. The method located between these two methods is the print timing data T of the prior art.
The rate of change (that is, the acceleration of the carriage) is calculated from 1, T2, ..., The printing timing data T1, T2, T2, T2, ... This is a method of dividing the time interval of ... into N time data. This last method is practical because it is simple and fairly accurate.

The print timing correction table 13 also includes a print timing correction table for each resolution. 1/144 in each print timing correction table
Correction time data for correcting the print timing with an accuracy of 0 inch is registered. The most accurate method for obtaining this correction time data is to actually run the carriage at the design stage, measure the time at each position of the 1440 inch pitch, and use the measured value as the correction time data. Is. Further, the simplest method is to calculate print timing data of each resolution according to the conventional technique by 1/144.
This is a method of equally dividing the time data corresponding to 0 inch and calculating the correction time data using the value. For example, resolution 9
In the case of 0 dpi, the print timing data T of the prior art
Values obtained by dividing 1, T2, ... Into 16 equal to T1 / 16, T2 / 1
In this method, the correction time data is calculated by multiplying or adding 6 and so on as a unit. 1/1440
This is a method of preparing a large number of possible correction time data such as correction time data corresponding to inches, correction time data corresponding to 2440 inches, and so on. Whichever method is used, for each resolution, correction time data equivalent to 1/1440 inch, correction time data equivalent to 2/1440 inch, correction time data equivalent to 3/1440 inch, ...
Thus, many possible correction time data are obtained and registered in the print timing correction table for each resolution.

The print timing determination unit 15 loads the print timing table corresponding to the resolution from the print timing table 11. Further, a correction table corresponding to the resolution is loaded from the print timing correction table 13,
From the table, the optimum correction time data is selected for each row in consideration of the current carriage stop position, the next print start position, Uni-correction and Bi-D correction. Then, for each line, each time data T in the print timing table
From 0, T11, T12, ... And the selected correction time data, the print timing of each dot position of the row is determined,
It is given to the head control circuit 17. The head control circuit 17 gives a drive signal to the head 19 through the head drive circuit 18 at the determined printing timing of each dot.

FIG. 5 shows a method for determining the print timing.

In the print timing table, after the first print timing data T0, the time data T of the small section is written.
11, T12, ... Are prepared, and T1 = for the print timing data T1, T2 ,.
T11 + T12 + T13 + T14, T2 = T21 + T2
2 + T23 + T24 and so on. Here, taking the case of a resolution of 90 dpi as an example, T1, T
2, ... are times corresponding to 1/90 inch, T11,
Each of T12, T13, T14, ... Is the time corresponding to 4/1440 inches.

The print timing determination unit 15 first sets the selected correction time data α to the first print timing data T.
In addition to 0, the print timing data for the first dot is determined as T0 + α. Next, the print timing determination unit 15 determines to which subsection of the subsections in the print timing table the correction time data α has reached, and sets a pointer that points to the subsection next to the subsection that has reached. set. In the illustrated example, since α reaches the second small section T12, the pointer of the next third small section T13 is set. Next, four small sections T13, T14, T21 and T22 counting from the small section pointed by this pointer are read and added to determine the print timing data of the second dot as T13 + T14 + T21 + T22. Then, the pointer of the small section T23 next to the section where the reading is completed is set. Next, similarly, the added value T23 + T24 + T3 of four small sections counted from the small section indicated by the pointer
1 + T32 is determined as the print timing data for the third dot, and the pointer for the next small section T33 is set. Thereafter, similarly, four small sections counted from the pointer are read and added to obtain the print timing data for the next dot. By this method, the increase in the speed of the carriage due to the timing shift corresponding to the correction time data α can be effectively reflected in the print timing data of each dot, so that the print position accuracy in the acceleration section is improved as compared with the conventional case.

When the correction time data α reaches the middle position of a certain small section, the second print timing data is determined by including the small section in which α reaches the middle. It may be 4 sections, or it may be 4 sections from the next small section without including a small section where α has reached, or, for example, by rounding off the proportion of the α portion in the small section, You may make it select whether to include the small section.

FIG. 6 shows the overall processing flow of the print timing determination unit 15. Hereinafter, the illustrated processing 1 to processing 4 will be described in order.

(1) Process 1 First, the top address of the selected specific resolution is selected from the top addresses of the print timing table and print timing correction table of each resolution stored in advance, and the top address is selected. The storage device is accessed by using the print timing table and the print timing correction table corresponding to the selected resolution.

(2) Process 2 Next, processes 2 to 4 are repeated for each row. In the process 2, the correction amount based on the current stop position and print start position of the carriage motor, and the correction amount for Uni-D correction and Bi-D correction are calculated, and the loaded print timing correction table is calculated. The optimum correction time data α is selected from among the above.

(3) Process 3 Next, the first time data T0 is read from the loaded print timing table, and the selected correction time data α is added to this to determine the corrected first print timing data T0 + α. , This is set in the print interrupt timer, and the timer is started at the same time as printing is started.

(4) Process 4 When the time T0 + α set by the interrupt timer is counted, the print interrupt process is performed and the drive signal is sent to the head to print the first dot, and at the same time, described with reference to FIG. The print timing data for the second dot is determined by the method, set in the print interrupt timer, and the timer is started. Thereafter, every time the time set by the timer is counted, the print interrupt process is similarly performed. This gives 2
The second and subsequent dots are, for example, T1 as described in FIG.
3 + T14 + T21 + T22, T23 + T24 + T31
It is struck at time intervals such as + T32. When the acceleration section of the carriage ends and the vehicle starts traveling at a constant speed, constant print timing data corresponding to the constant traveling speed is set in the print interrupt timer, and dots are printed at constant time intervals. When the last dot in one line has been hit, the process returns to process 2 and the process for the next line is started.

FIG. 7 shows the above-mentioned processing 2 in more detail. Hereinafter, the processes 21 to 23 shown in the figure will be sequentially described.

(1) Process 21 First, before starting the printing of each line, the current stop position of the carriage, the printing start position of each line, the printing resolution, the correction distance for Uni-D correction, and the correction distance for Bi-D correction are set. Based on this, the correction distance for aligning the first dot with the correct print position is determined in units of 1/1440 inch, for example.

(2) Process 22 Next, the correction time data α corresponding to the determined correction distance is acquired from the print timing correction table.

(3) Process 23 Further, based on the acquired correction time data α, a small section for determining the print timing data of the second dot is set in the print timing table by the method described with reference to FIG. It is decided from where to read, and a pointer pointing to the small section (T13 in the example of FIG. 5) at which the reading is started is set.

FIG. 8 shows a functional configuration of accelerated printing control according to the second embodiment of the present invention.

In the above-described first embodiment, there is one print timing table for each resolution, and the time data of each small section is registered therein, and in one print interrupt process, N times the table is used. Data of N small sections are acquired by repeating reading once, and these are added to calculate one print timing data. However, especially when high-speed printing is realized, since it is desired to shorten the interrupt processing time for one time as much as possible, it is desirable to reduce the number of times the table is accessed and the calculation processing. In this respect, the second embodiment shown in FIG. 8 is excellent.

As shown in FIG. 8, at each print resolution, a plurality of print timing tables corresponding to the number of variations of how to determine the print data according to the size of the correction time data α are prepared. For example, in the case of a resolution of 90 dpi, four types of print timing tables are prepared.

The first print timing table is for the case where the correction time data α is zero, and the first print timing data T00 = T0 and the printing of the second and subsequent dots that have been precalculated by the method described in FIG. Timing data T1
0, T20, ... Are registered. Where T10 = T
11 + T12 + T13 + T14, T20 = T21 + T2
2 + T23 + T24, ...

The second print timing table is for the case where the correction time data α is greater than zero and less than or equal to the first small section T11. Here, the print timing data T10, T20, ... For the second and subsequent dots, which have been calculated in advance by the method described in FIG. 5, are registered. Where T
10 = T12 + T13 + T14 + T21, T20 = T
22 + T23 + T24 + T31, ... For the first print timing data T00, T00 = T
Since it is calculated by 0 + α, it is not registered in the table.

In the third print timing table, the correction time data α is larger than the first small section T11 and is equal to or less than the addition T11 + T12 of the first and next small sections. Here, 2 calculated in advance by the method described in FIG.
Print timing data T10, T2 for the second and subsequent dots
0, ... Are registered. Where T10 = T13 +
T14 + T21 + T22, T20 = T23 + T24 + T
31 + T32, ... Note that the first print timing data T00 is not registered in the table because it is calculated by T00 = T0 + α.

In the fourth print timing table, the correction time data α is larger than the addition T11 + T12 of the first and next small sections and the addition T11 + of the first to third small sections is added.
This is the case where T12 + T13 or less. Here, Fig. 5
The print timing data T10, T20, ... For the second and subsequent dots, which have been calculated in advance by the method described in Section 1, are registered. Here, T10 = T14 + T21 + T22 + T
23, T20 = T24 + T31 + T32 + T33, ... Note that the first print timing data T00 is not registered in the table because it is calculated by T00 = T0 + α.

When the correction time data α is larger,
Any of the four types of tables described above can be used. For example, α is greater than T11 + T12 + T13 and T11
When it is less than + T12 + T13 + T14, the first table in the case of α = 0 can be used. However, for the second and subsequent dots, T10 is ignored and the data from T20 onward is used.

In short, the number of tables equal to the number N of small sections obtained by dividing one dot pitch is prepared for one resolution. Therefore, the resolution is 96 dpi
In the case of 5, since it is divided into five small sections as shown in FIG. 2, five print timing tables are prepared.

On the other hand, the print timing correction table 23 is the same as in the case of the first embodiment.

When the print timing determination unit 25 selects specific correction time data α from the print timing correction table, the print timing determination unit 25 selects one print timing table corresponding to the size of α from the print timing table 21 and loads it. The first print timing T00 is T0.
0 = T0 + α, but the print timing data for the second and subsequent dots is the print timing data T10, T2 calculated from the selected print timing table.
0, ... Is read and used as it is.

The above-described embodiments are merely for explaining the present invention, and the technical scope of the present invention is not limited to the above-mentioned embodiments. The present invention can be implemented in various forms other than the specific forms described above without departing from the spirit of the present invention. For example, the number N of 1-dot pitch divisions may be larger or smaller than in the above-described embodiment.

[Brief description of drawings]

FIG. 1 is a basic conceptual diagram of accelerated printing control.

FIG. 2 is a block diagram of conventional accelerated printing control.

FIG. 3 is a diagram showing a conventional print timing determination method.

FIG. 4 is a block diagram of accelerated print control according to the first embodiment of the invention.

FIG. 5 is a diagram showing a printing timing determination method of the same embodiment.

FIG. 6 is a flowchart of print timing determination processing.

FIG. 7 is a flowchart detailing processing 2 in FIG.

FIG. 8 is a block diagram of accelerated printing control according to a second embodiment of the invention.

[Explanation of symbols]

1, 11, 21 Print timing table 3, 13, 23 Print timing correction table 5, 15, 25 Print timing determination unit 7, 17, 27 Head control circuit 8, 18, 28 Head drive circuit 9, 19, 29 heads

Claims (11)

(57) [Claims] 1. A serial printer for printing in an acceleration section of a carriage, the distance between a current stop position of the carriage and a print start position.
The drive timing data for the first printing is supplemented according to the separation.
By correcting, the first print timing determination unit that determines the print timing of the first dot, and a large number of small sections within the acceleration section of the carriage,
Wherein from many time data the carriage travel time respectively in each of the plurality of small sections such that a plurality of N successive small sections corresponding to one dot pitch,
Small area where the print timing of the first dot has arrived
A large number of sets of time data after the interval or the subsequent small section are set, with N consecutive time data as one set, and the addition value of the N time data in each selected set is set to 2 in the row. A serial printer that includes a subsequent print timing determination unit that determines the print timing of each dot until the end of the second and subsequent acceleration sections , and that drives the print head at the determined print timing. 2. The serial printer according to claim 1,
The first print from the start of printing to the time of the first dot
A storage unit for storing timing data is further provided, and the large number of time data is converted into the print timing data.
It is time data of the following small section, and the first print timing determination unit displays the current time of the carriage.
The first depending on the distance between the stop position and the print start position
Print the first dot according to the drive timing data for printing
The first time
A serial printer that determines the dot print timing. 3. The serial printer according to claim 2, wherein the storage unit supports a plurality of print resolutions and has one print timing table for each resolution. 4. The serial printer according to claim 1, wherein the subsequent print timing determination unit has a print timing table in which an added value of the time data of each set is registered, and from the print timing table, A serial printer that determines the print timing of each dot by reading a set time data addition value. 5. The serial printer according to claim 4, wherein each of the resolutions has N print timing tables in which a combination of N time data included in each set is different. 6. A method for determining a print timing of a serial printer which performs printing in an acceleration section of a carriage, wherein a distance between a current stop position of the carriage and a print start position is set.
The drive timing data for the first printing is supplemented according to the separation.
Correcting the process to determine the print timing of the first dot, and a number of small sections in the acceleration section of the carriage,
Wherein from many time data the carriage travel time respectively in each of the plurality of small sections such that a plurality of N successive small sections corresponding to one dot pitch,
Small area where the print timing of the first dot has arrived
A large number of sets of time data after the interval or the subsequent small section are set, with N consecutive time data as one set, and the addition value of the N time data in each selected set is set to 2 in the row. A method for determining the print timing of each dot until the end of the second and subsequent acceleration sections , and a print timing determination method for a serial printer that drives the print head at the determined print timing. 7. The method according to claim 6, wherein the step of determining the print timing of each of the second and subsequent dots is based on a print timing table prepared in advance in which time data of the plurality of small sections is registered. , A step of reading N sets of time data of each set, and a step of determining the print timing of each dot by adding the N times, and a print timing determination method for a serial printer. 8. The method according to claim 6, wherein the step of determining the print timing of each of the second and subsequent dots is a print timing table prepared in advance in which the added value of the time data of each set is registered. From the above, the print timing determination method of the serial printer is configured to determine the print timing of each dot by reading the time data addition value of each set. 9. When performing printing in the acceleration section of the carriage, between the current stop position of the carriage and the print start position.
Drive timing data for the first printing according to the distance
The process of determining the print timing of the first dot by correcting , and a number of small sections in the acceleration section of the carriage,
Wherein from many time data the carriage travel time respectively in each of the plurality of small sections such that a plurality of N successive small sections corresponding to one dot pitch,
Small area where the print timing of the first dot has arrived
A large number of sets of time data after the interval or the subsequent small section are set, with N consecutive time data as one set, and the addition value of the N time data in each selected set is set to 2 in the row. A computer-readable recording medium in which a program for causing a computer to execute the process of determining the print timing of each dot until the end of the second and subsequent acceleration sections is completed . 10. A data structure for causing a computer to determine a print timing for printing in an acceleration section of a carriage of a serial printer, the data structure comprising a number of small sections in the acceleration section of the carriage,
Wherein from many time data the carriage travel time respectively in each of the plurality of small sections such that a plurality of N successive small sections corresponding to one dot pitch,
Small area where the print timing of the first dot has arrived
A data structure including a time data set after the interval or the subsequent small section , with a number of continuous N time data sets as one set, including a sum of N time data sets in each selected set, A computer-readable recording medium in which is recorded. 11. The recording medium according to claim 10, wherein each of the resolutions supported by the serial printer has N data structures in which a combination of N time data included in each set is different. .