JPH11245470A - Method and apparatus for controlling printing of printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure high printing quality to make constant a distance between printed dots even in an overshoot phenomenon by controlling to correct a generation timing for printing command signals to meet a speed deviation of a carriage at a constant speed area caused when a traction member is compressed and expanded. SOLUTION: A delay time (td, td+1......) is individually corrected based on a reference pulse which is a cycle T of driving pulses fed from a motor control part 14 to a stepping motor 5. A printing command signal is thus generated. That is, a generation timing for the printing command signals is controlled to be tight to meet an overshoot and to be loose to meet an undershoot following the overshoot. The generation timing for the printing command signals is adjusted in accordance with a movement speed of a carriage, so that deterioration in printing quality due to the overshoot and undershoot is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is applied to a printer which performs printing while reciprocating a print head, such as a serial dot printer, and more particularly to a printing control method and a printing control device capable of maintaining high printing quality. It is about.

[0002]

2. Description of the Related Art Among printers for printing characters or bit images in a dot matrix, a serial type printer is widely used because of its excellent cost performance. Among typical serial dot printers, a wire dot printer typically drives a carriage on which a print head is mounted in a reciprocating manner in a print line direction by a driving force of a carriage motor, and protrudes a dot wire arranged on the print head by a print command signal. By doing so, printing is performed on printing paper.

In a conventional printer of this type, a carriage on which a print head is mounted is configured to be movable along a guide shaft arranged in parallel with the longitudinal direction of a platen, and is driven by a carriage drive motor. It is configured to be reciprocated on a guide shaft via a timing belt as a pulling member.

Due to such a configuration, when the carriage is moved from one end of the guide shaft to the other end during printing, the carriage travels at a constant speed at a target speed, in an acceleration region where the carriage is accelerated from a stopped state to a constant speed. Through a constant speed region, and a deceleration region from a constant speed to a stop state.

In this case, in consideration of the product cost and the external dimensions of the product, it is impossible to use a motor having extremely large torque characteristics as a carriage motor. Accordingly, the distance required for deceleration is shorter than the distance required for accelerating the carriage. Accordingly, the relationship between the elapsed time and the moving speed of the carriage is substantially as shown in FIG.

[0006] In this type of conventional printer, the printing operation is performed only when the carriage is running at a target speed at a constant speed. However, when printing is performed only at the time of running at a constant speed, the time required for printing increases, and there is a problem that the throughput cannot be improved.
Therefore, printing is started (accelerated printing) while the carriage is accelerating from a stopped state to a certain speed, and in addition to this, a printing operation (decelerated printing) is performed while the carriage is decelerating from a certain speed to a stopped state. A printing control means configured as described above has also been proposed.

When the above-described accelerated printing and decelerated printing are performed, the distance that the carriage moves depends on the moving speed of the carriage. Therefore, if the printing operation is performed in this state, there is a problem that the dot interval is not constant. Therefore, in the printer configured as described above, in a state where the moving speed in the acceleration region and the moving speed in the deceleration region are sequentially changed, the print command signal given to the print head is adjusted so that the dot interval of printing on the printing paper is constant. It has been like that.

[0008]

Since the carriage on which the print head is mounted reciprocates via the timing belt as described above, a slight expansion and contraction action occurs due to the spring component of the timing belt.
8A and 8B show a simplified model of the carriage driving mechanism. FIG. 8A shows a state in which the timing belt has no spring component and the carriage is ideally driven, and FIG. This shows a state in which the timing belt has a spring component and the carriage is driven in the direction of the arrow. In the drawing, reference numeral 5 denotes a carriage drive motor, 8 denotes a timing belt stretched between a drive pulley 6 attached to a drive shaft of the motor 5 and a driven pulley 7,
Reference numeral 1 denotes a recording head mounted on the carriage 2 pulled by the timing belt 8.

As shown in FIG. 8B, in the acceleration region, the traction side is extended by ΔE due to the spring component Sp1 existing on the traction side (the traveling direction of the carriage) of the timing belt 8 (at the same time, the belt on the opposite side is shifted). The carriage is pulled in a state where the spring component Sp2 is contracted). Further, when the vehicle enters the constant speed region, a phenomenon occurs in which the spring component Sp1 on the traction side contracts (at the same time, the spring component Sp2 of the belt on the opposite side expands) due to the acceleration of the mass of the drive system including the carriage. Overshoot and undershoot phenomena of converging to a target constant speed while shrinkage occur alternately occur.

FIG. 9 schematically illustrates this phenomenon, and FIG. 9A shows a state of the carriage in a forward movement operation. In other words, the carriage shifts from the stopped state in the forward path to the constant speed area B in which the carriage travels at the target speed at a constant speed via the acceleration area A in which the carriage accelerates to a constant speed. At the beginning when the vehicle enters the constant speed region B, an overshoot OS is generated by the above-described operation, and an undershoot is subsequently generated. Then, this is gradually absorbed, and thereafter, the vehicle passes through a deceleration region C from a constant speed to a stop state. Although an overshoot phenomenon occurs at the beginning of the deceleration region C, it is not shown in the drawing.

FIG. 9B shows a state in which the carriage is moved backward. In the same way as described above, the carriage travels through the acceleration region C in which the carriage is accelerated from the stopped state to a constant speed, and then travels at a constant speed at the target speed.
Move to Overshoot OS occurs at the beginning of the constant speed region D, is gradually absorbed, and then passes through a deceleration region E from a constant speed to a stop state, and this reciprocation is repeated. Note that an overshoot phenomenon also occurs at the beginning of the deceleration region E, but is not shown in the drawing.

The degree of the overshoot and undershoot is determined by the effective spring component (Sp) when the starting point of the carriage changes according to the format data.
1, Sp2) changes, and the vertical width and cycle of the over (under) shoot change accordingly. The form also changes in the forward movement and the backward movement of the carriage. In a state in which such an over (under) shoot occurs, the speed of the carriage is naturally not constant, and the dot interval of printing becomes irregular, thereby causing a problem that the printing quality is deteriorated.

The present invention has been made by paying attention to such a point, and controls the printing dot interval to be constant even when the above-mentioned over (under) shoot phenomenon occurs, thereby achieving high printing quality. It is an object of the present invention to provide a print control method and a print control device that can ensure the print quality.

[0014]

A printing control method for a printer according to the present invention, which has been made to achieve the above-mentioned object, comprises a method of reciprocating a carriage on which a print head is mounted by a driving force of a carriage driving motor via a pulling member. A print control method for a printer which is driven and supplies a print command signal to the print head, wherein when the carriage is pulled by a traction member and shifts from an acceleration region to a constant speed region, The generation timing of the print command signal is corrected and controlled in accordance with the speed deviation of the carriage in the constant speed region caused by the expansion and contraction of the traction member.

In the case where bidirectional printing is performed in each of the forward movement operation and the backward movement operation of the carriage, printing corresponding to a speed deviation of the carriage when the carriage shifts to the forward constant speed region. The correction of the generation timing of the command signal and the correction of the generation timing of the print command signal corresponding to the speed deviation of the carriage when the carriage shifts to the backward movement constant speed region are separately executed.

Further, according to the print control method of the printer according to the present invention, the generation timing of the print command signal is corrected and controlled in accordance with the transition position of the carriage to the constant speed area.

The printing control device for a printer according to the present invention drives a carriage on which a print head is mounted to reciprocate by a driving force of a carriage drive motor via a traction member, and sends a print command signal to the print head. A print control device of a printer adapted to supply,
A motor control unit that supplies a pulse signal for driving the motor to a carriage drive motor; a print command signal generation unit that supplies a print command signal to the print head in synchronization with the movement of the carriage drive motor; And a correction means for determining the timing at which the carriage has shifted from the acceleration region to the constant speed region, and for correcting the generation timing of the print command signal generated by the print command signal generator when the carriage has shifted to the constant speed region. .

In this case, the correction means preferably reads the correction data from the correction value storage table, and corrects the generation timing of the print command signal from the print command signal generator based on the read correction data. Is done.

Further, in a printer which performs bidirectional printing in each of the forward movement operation and the backward movement operation of the carriage, the correction means corresponds to a speed deviation of the carriage when the carriage shifts to the forward constant speed region. To correct the forward movement correction data for correcting the generation timing of the print command signal, and the generation timing of the print command signal corresponding to the speed deviation of the carriage when the carriage shifts to the backward constant speed region. It is desirable to obtain the backward movement correction data from the correction value storage table.

The correction value storage table is preferably configured in a format in which correction data is stored based on a printing format. In a preferred embodiment, the correction means is configured to generate a print command signal by individually correcting a delay time with respect to a reference pulse. In this case, a pulse signal for driving a carriage drive motor is preferably used as the reference pulse.

According to the printing control method and the printing control device as described above, the correction data is read from the correction value storage table based on, for example, the setting of the printing format.
The correction data is used to correct and control the generation timing of the print command signal in accordance with the speed deviation of the carriage in the constant speed region caused by the expansion and contraction of the timing belt as the traction member. As a result, the recording head performs a printing operation in accordance with the speed deviation of the carriage, and as a result, high-quality printing is performed.

In this case, when bidirectional printing is performed, the generation timing of the print command signal is particularly controlled based on the correction value in the forward movement operation and the correction value in the backward movement operation.

Further, a correction value is read out according to the position of the carriage shifting to the constant speed area based on the setting of the printing format,
The generation timing of the print command signal is corrected and controlled accordingly.

[0024]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a configuration of a printer adopting the present invention. FIG. 1 is a perspective view showing an example of a print head driving mechanism in a printer. The print head 1 is fixed to a carriage 2, and the carriage 2 is mounted so as to be able to reciprocate in a print line direction by a guide shaft 3 and an auxiliary shaft 4 arranged in a horizontal direction. The carriage 2
Is a timing belt 8 stretched between a drive pulley 6 attached to a drive shaft of a carriage drive motor 5 and a driven pulley 7 disposed at a position facing the drive pulley 6 in the axial direction of the guide shaft 3. Thereby, the guide shaft 3 can be driven back and forth in the printing line direction.

The printing head 1 mounted on the carriage 2 is configured to print bidirectionally on the printing paper P arranged on a platen (not shown). The print head 1 is of a well-known wire dot impact type that prints by hitting printing paper with a plurality of wires.

FIG. 2 shows the configuration of a control circuit for controlling the head drive mechanism and correcting the timing of generating a print command signal. In the following, accelerated printing is started during a period of time during which the carriage is accelerating and reaches a constant speed, and constant speed printing is continuously performed until the carriage reaches an end point of a constant speed region where the carriage travels at a constant speed at a target speed. The configuration and operation will be described based on a printer that performs printing control.

In FIG. 2, the control circuit 11 includes a CPU 1
The CPU 12 is connected to a ROM 13 as a storage medium. In the ROM 13, a control data storage table for storing data indicating a print start point, a print timing correction start point, and a print end point, which will be described later, and a correction value storage table for storing print timing correction values are constructed. And CPU1
2, the first to third count values indicating the print start point, the print timing correction start point, and the print end point are read from the control data storage table, and the print timing is read from the correction value storage table. Is also read out.

A motor control unit 14 is connected to the CPU 12, and the motor control unit 14 supplies a drive pulse (phase switching signal) to the stepping motor 5 as a carry drive motor in accordance with a command from the CPU 12. The stepping motor 5 is driven to rotate in a reciprocating direction. The format of the drive pulse to be supplied to the stepping motor 5 is also written in the ROM 13, and the format of the motor drive pulse and the format of the motor drive pulse are simultaneously read from the control data storage table and the print timing correction value storage table.
It is desirable to be configured so that it can be taken into

The driving pulse supplied from the motor control unit 14 to the stepping motor 5 is supplied to the first counter 15
The counter is configured to be supplied to the second counter 16 and the third counter 17, respectively, and these counters count up the number of pulse signals supplied to the stepping motor 5. Further, a reset signal is applied from the CPU 12 to the first to third counters 15 to 17,
It is configured so that the count value of each counter can be reset to zero.

The CPU 12 is connected to a first setting section 18 to a third setting section 20. Each of the setting sections has the first count value (the position of the printing start point which is read from the ROM 13). The second count value (the number of pulses indicating the position of the print timing correction start point), the third count value
The count value (the number of pulses indicating the position of the printing end point) is configured to be stored.

The count value counted up by the first counter 15 and the first count value set in the first setting unit 18 are configured to be supplied to a first comparator 21, The comparator 21 compares the first count value set in the first setting unit 18 with the count value of the first counter 15 and outputs a match output to the CPU 12 when they match. Have been.

Similarly, the count value counted up by the second counter 16 and the second count value set in the second setting unit 19 are configured to be supplied to a second comparator 22. The second comparator 22 calculates the second count value set in the second setting unit 19 and the second counter 1
6, and outputs a coincidence output to the CPU 12 when they coincide with each other.

Similarly, the count value counted up by the third counter 17 and the third setting unit 20
Is set to be supplied to the third comparator 23, and the third comparator 23
The third count value set in the setting unit 20 is compared with the count value of the third counter 17, and when they match, a match output is output to the CPU 12.

On the other hand, a print timing correction unit 24 and a print command signal generation unit 25 are connected to the CPU 12, and the print timing correction unit 24 is connected to the print command signal generation unit 2
5 constitutes a correction means for correcting the generation timing of the print command signal generated by the control unit 5.

When receiving a coincidence signal from the first comparator 21, the CPU 12 issues a command to output a print command signal to the print command signal generator 25. When receiving the coincidence signal from the device 22, the CPU 12 issues a command to the print timing correction unit 24 to correct the print timing.
Further, when a match signal is received from the third comparator 23,
The CPU 12 issues a command to the print command signal generator 25 to stop outputting the print command signal.

A print head drive unit 26 is connected to the print command signal generation unit 25. The print head drive unit 26 receives a print command signal from the print command signal generation unit 25 during a period in which the print command signal is supplied. The power is amplified and the dot wires of the print head 1 are driven.

FIG. 3 shows an example in which the print timing is corrected together with the print start and print stop controls performed by the control circuit 11 shown in FIG. That is, FIG. 3A shows the carriage speed in the forward movement of the carriage.
3A is an enlarged view of the characteristic shown in FIG. FIG. 3B shows a print command signal output from the print command signal generator at this time.

That is, the carriage is moved from a point G in an acceleration area A where the carriage reaches a certain speed from a stop state on the outward path.
A print command signal is supplied to the print head, and accelerated printing is performed from this point G. Further, a print command signal is continuously supplied to the print head until reaching the end point H of the constant speed region B where the carriage travels at a constant speed at the target speed. In the deceleration region C where the carriage stops at a constant speed, the supply of the print command signal to the print head is stopped.

Here, in the accelerated printing starting from the point G, the print command signal is controlled so that the pulse interval is gradually narrowed substantially in proportion to the carriage speed. In the above-mentioned overshoot region generated from the starting point K of the constant speed region B, the pulse width of the print command signal is controlled so as to be dense in accordance with the shoot width and the period. The control is performed so that the pulse interval of the print command signal becomes coarse in accordance with the shoot width and the cycle.

From the constant speed region B passing through the over (under) chute region to the end point H, the pulse interval of the print command signal is made equal, and when the end point H of the constant speed region B is reached. , The output of the print command signal is stopped.

FIG. 4 is a flowchart mainly showing the operation of the CPU 12 for executing the print timing shown in FIG. Note that the flowchart shown in FIG. 4 assumes a case of printing one page.

In step S11 in FIG.
U12 accesses the ROM 13 and determines the first count value, that is, the number of pulses corresponding to the position G where printing is started in the acceleration area A, and the second count value, that is, the constant, based on the data of the set print format. The number of pulses corresponding to the starting point position K of the speed region B and the third count value, that is, the number of pulses corresponding to the ending point position H of the constant speed region B are RO
It is read from the control data storage table constructed in M13.

The format of this table is, for example, as schematically shown in FIG. 5, the paper size (A4, A3, B5, B4, postcard, free) and the paper direction (portrait, landscape) which are print format setting data. The print width Px is obtained based on setting data such as the number of characters per line, character spacing, and character size.
The first count value (nn... N) as the number of pulses corresponding to the position G where printing is started corresponding to the printing width Px
n), a second count value (nn... nn) as the number of pulses corresponding to the start point K of the constant speed region B, and a third count value (nn...) as the number of pulses corresponding to the position H at which printing is stopped. nn).

From the control data storage table described above, the first
When the count value to the third count value are read, in step S12, the CPU 12 sets the first count value to the first count value.
Writing to the setting unit 18, writing the second count value to the second setting unit 19, and writing the third count value to the third setting unit 20. Subsequently, in step S13, the CPU 12 reads the correction data of the print timing from the correction value storage table. The correction data of the print timing is stored in a table format corresponding to the print width Px as shown as a time axis correction function in FIG.
U12 writes this temporarily in a RAM (not shown) or the like, and executes time axis correction of the print command signal in an over (under) shoot area as described later.

Subsequently, the CPU 12 sends a reset signal to the first to third counters 15 to 17 in step S14 to reset each of the counters 15, 16 and 17 to zero. Then, in step S15, the CPU 12 issues a command to the motor control unit 14, and the motor control unit 14 receiving the command supplies a drive pulse to the stepping motor 5 as a carriage drive motor. Therefore, the carriage is driven by the stepping motor 5 and moves along the guide shaft 3 arranged in the horizontal direction.

In this case, the amount of movement of the carriage, that is, the number of drive pulses supplied from the motor control unit 14 to the stepping motor 5 is determined based on the print format setting data described above.

At the same time, in step S16, the first to third counters 15 to 17 receive a drive pulse from the motor control unit 14 and count up the number of pulses. Then, in step S17, the first comparator 21 compares the first count value set in the first setting section 18 with the count value of the drive pulse counted up by the first counter 15, and reaches the first count value. It is determined whether or not it has been performed. When the first comparator 21 determines that the first count value has been reached, the first comparator 21
, And the CPU 12 outputs an operation output to the print command signal generator 25 in step S18. As a result, a print command signal is output from the print command signal generator 25 to the print head driver 26, and the print head 1 starts printing.

The printing timing in this case is substantially proportional to the pulse interval of the driving pulse supplied from the motor control unit 14 to the stepping motor 5. Strictly speaking, in the acceleration area of the carriage, the elongation of the timing belt and the time from when the print command is given to when the leading end of the dot wire reaches the recording paper to form dots (so-called flight time) are taken into consideration. It is necessary to adjust the print timing at this time, but the description is omitted here.

Subsequently, in step S19, the second comparator 22 compares the second count value set in the second setting unit 19 with the count value of the drive pulse counted up by the second counter 16, and It is determined whether the count value has been reached. When the second comparator 22 determines that the second count value has been reached, the second comparator 22
2, a command output is supplied, and in step S20, the correction of the print timing is started based on the correction data of the print timing.

FIG. 6 shows a simple model of the correction of the print timing at this time.
6A shows a drive pulse supplied from the motor control unit 14 to the stepping motor 5, and FIG. 6B shows a state of a print command signal subjected to timing correction. That is, in the acceleration region A, the pulse interval of the print command signal is set corresponding to (substantially in proportion to) the cycle of the drive pulse supplied to the motor (... T-2, T-1). Then, as described above, the second comparator 2 indicating that the shift to the constant speed region B has been performed.
2, the CPU 12 issues a command to the print timing correction unit 24, and generates a print command signal by using the print timing correction data from the correction value storage table read out in step S13. Execute time axis correction.

That is, the motor drive pulse having the cycle T is used as a reference pulse, and the delay time (td, td +
1...) To generate a print command signal. In short, the control is performed so that the timing of generating the print command signal is made dense in accordance with the overshoot, and the timing of generating the print command signal is controlled so as to be coarse in response to the undershoot following the overshoot.

Therefore, the generation timing of the print command signal is adjusted according to the moving speed of the carriage, and as a result, deterioration of the print quality due to overshoot and undershoot can be prevented.

In this case, the degree of occurrence of the overshoot and the subsequent undershoot is determined in the case where the starting point of the carriage changes according to the format data as described above.
The constants of the effective spring components (Sp1, Sp2) shown in FIG. 8 change, and the vertical width and cycle of the over (under) shoot change accordingly. The form also changes in the forward movement and the backward movement of the carriage. Therefore, the degree of occurrence is measured in advance and written as a time axis correction function in the correction value storage table.

Next, in step S21, the third comparator 23 compares the third count value set in the third setting section 20 with the count value of the drive pulse counted up by the third counter 17, and It is determined whether the count value has been reached. When the third comparator 23 determines that the third count value has been reached, the third comparator 23
, And the CPU 12 stops the operation output to the print command signal generator 25 in step S22. As a result, the print command signal from the print command signal generator 25 to the print head driver 26 is stopped, and the print operation of the print head 1 by the print head driver 26 is stopped.

Then, in step S23, the CPU 1
Step 2 determines whether or not the print line has reached the bottom line. If it is determined that the print line has not reached the bottom line, the process returns to step S13, where printing is performed by the return operation.

Although the degree of over (under) shoot in this backward movement is different from that in the forward movement of the carriage, the time axis correction as correction data at the time of forward movement is stored in the correction value storage table. A function and a time axis correction function, which is correction data at the time of the backward movement, are simultaneously read in step S13, and two times are read in accordance with the forward movement operation of the carriage managed by the CPU or the status flag indicating the forward movement operation. It is preferable that the axis correction function be used alternatively. If it is determined in step S23 that the bottom line has been reached, the operation is stopped, and printing for one page is completed.

Here, as shown in FIG. 9, in each of the accelerated printing modes in the forward movement operation and the backward movement operation of the carriage, the number of pulses supplied to the stepping motor is Pi, and the forward movement operation and the backward movement of the carriage are performed. The number of pulses supplied to the stepping motor in each deceleration region in the operation is Pb, and the number of pulses supplied to the stepping motor in each acceleration region in the forward movement and the backward movement of the carriage is Pb.
When a is set, it is desirable that the control is performed so that Pa = Pi-Pb.

In other words, the number of pulses (Pa-Pi) applied in the non-print acceleration area is controlled to be equal to the number Pb of pulses applied in the deceleration area. By setting the deceleration area and the non-print acceleration area to be substantially equal in this way, it is possible to improve the throughput in consideration of the time required for actually printing one page.

[0059]

As is apparent from the above description, according to the printer adopting the print control method and the print control apparatus according to the present invention, the speed deviation of the carriage which occurs when the carriage shifts from the acceleration area to the constant speed area is reduced. Correspondingly, the generation timing of the print command signal is corrected and controlled.

Therefore, even if a speed deviation occurs in the carriage in the constant speed region, the printer is controlled so that the printing dot interval is constant, and it is possible to provide a printer capable of ensuring high printing quality.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a drive mechanism of a print head in a printer according to the present invention.

FIG. 2 is a block diagram showing an example of a control circuit for controlling the drive mechanism shown in FIG.

FIG. 3 is a time chart showing a control state of print timing performed by a control circuit shown in FIG. 2;

FIG. 4 is a flowchart mainly explaining the operation of a CPU in the control circuit shown in FIG. 2;

FIG. 5 is a diagram showing an example of a data storage table and a correction value storage table used in the control circuit shown in FIG.

FIG. 6 is a time chart showing a control state of print timing based on a motor drive pulse performed by the control circuit shown in FIG. 2;

FIG. 7 is a time chart showing operating characteristics of the carriage.

FIG. 8 is a schematic diagram illustrating operating characteristics of a carriage.

FIG. 9 is a time chart showing an overshoot state occurring in a constant speed traveling region of the carriage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Print head 2 Carriage 3 Guide shaft 5 Carriage drive motor 8 Timing belt (traction member) 11 Control circuit 12 CPU 13 R0M 14 Motor control unit 15 First counter 16 Second counter 17 Third counter 18 First setting unit 19 Second Setting section 20 third setting section 21 first comparator 22 second comparator 23 second comparator 24 print timing correction section 25 print command signal generation section 26 print head drive section A, D acceleration area B, E constant speed area C , F Deceleration area G, I Printing start position H, J Printing end position P Printing paper

Claims (9)

[Claims] 1. A printing control method for a printer, wherein a carriage on which a print head is mounted is reciprocated by a driving force of a carriage drive motor via a traction member, and a print command signal is supplied to the print head. In the case where the carriage is pulled by the traction member and shifts from the acceleration region to the constant speed region, the print command signal is provided in accordance with a speed deviation of the carriage in the constant speed region caused by expansion and contraction of the traction member. A print control method for a printer, wherein the print control method corrects and controls the occurrence timing of the print. 2. A print command corresponding to a speed deviation of the carriage when the carriage shifts to a forward movement constant speed area when printing is performed bidirectionally in each of the forward movement operation and the backward movement operation of the carriage. 3. The method according to claim 1, wherein the correction of the signal generation timing and the correction of the print command signal generation timing corresponding to the speed deviation of the carriage when the carriage shifts to the backward movement constant speed region are separately executed. 2. The printing control method of the printer according to 1. 3. The print control method for a printer according to claim 1, wherein the generation timing of the print command signal is corrected and controlled in accordance with the position of the carriage shifting to a constant speed area. . 4. A print control device for a printer, wherein a carriage on which a print head is mounted is reciprocally driven by a driving force of a carriage drive motor via a traction member, and a print command signal is supplied to the print head. A motor control unit that supplies a pulse signal for driving the motor to the carriage drive motor; and a print command signal generation unit that supplies a print command signal to the print head in synchronization with the movement of the carriage drive motor. Correction means for determining the timing at which the carriage has shifted from the acceleration area to the constant speed area, and for correcting the generation timing of the print command signal generated by the print command signal generation unit when the carriage has shifted to the constant speed area. A printing control device for a printer, comprising: 5. The correction means reads correction data from a correction value storage table, and corrects the generation timing of a print command signal from a print command signal generation unit based on the read correction data. The print control device for a printer according to claim 4, wherein: 6. In a printer which performs bidirectional printing in each of a forward movement operation and a backward movement operation of a carriage, the correction means is adapted to correspond to a speed deviation of the carriage when the carriage shifts to a forward movement constant speed region. Forward movement correction data for correcting the generation timing of the print command signal and correction of the generation timing of the print command signal corresponding to the speed deviation of the carriage when the carriage shifts to the backward constant speed region. 5. The printing control apparatus for a printer according to claim 4, wherein the correction control data is obtained from the correction value storage table. 7. The print control device for a printer according to claim 5, wherein the correction value storage table is configured to store correction data based on a print format. 8. The printer according to claim 4, wherein the correction unit generates a print command signal by individually correcting a delay time with respect to a reference pulse. Printing control device. 9. The printing control device according to claim 8, wherein a pulse signal for driving a carriage driving motor is used as the reference pulse.