JP2002144661A - Printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printer capable of stabilizing operation without lowering printing processing capacity even when a printing head unit is continuously reversed retracted, stopped and started. SOLUTION: The printer has a linear motor for reciprocatingly moving the printing head unit along a constant direction, and an elastic spring exerting reversal energizing force on the printing head unit in the vicinity of both ends of a reciprocally moving section when the printing head unit is reciprocally moved by the driving force of the linear motor. The microcomputer built in the printer commands the linear motor to generate the driving force opposed to the reversal energizing force to once retract the printing head unit to a position receiving no reversal energizing force (E, F), and variably controls timing for returning the printing head unit to a section (reversal section) to which the reversal energizing force of the elastic spring is applied from the retracted stop position (one-dot broken line) when the printing head unit is resumed immediately after retraction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus which performs printing while reciprocating a print head unit in a predetermined direction using, for example, a driving force of a linear motor as a main power.

[0002]

2. Description of the Related Art For example, as a printing apparatus for performing high-speed printing on a continuous form or the like by a dot impact method, a linear motor for reciprocating a print head unit in a fixed direction, and a driving force of the linear motor are used. When the print head unit reciprocates while performing a constant speed / reversing motion, a spring for applying a reversing biasing force to the print head unit near both ends of the reciprocating section, and a displacement when the print head unit reciprocates. Some have a linear encoder or the like for detecting an error.

In this type of printing apparatus, a print head unit is connected to a linear motor via a belt / pulley mechanism, and the linear motor is driven in response to a command from a control unit such as a microcomputer, thereby driving the linear motor. The print head unit is configured to reciprocate via force. In such a linear motor, the mover to which the motor coil is attached operates in a direction opposite to the print head unit via a belt pulley mechanism.
This mover also functions as a counter balancer. Further, a spring is provided near both ends of the section where the print head unit reciprocates to apply a reversing biasing force to the print head unit. The print head unit is switched from the constant velocity movement to the reverse movement or vice versa by the force combined with the driving force.

The position and speed at which the print head unit reciprocates are calculated by a control unit based on a detection signal from a linear encoder whose linear scale is to be detected, whereby the print head unit is determined in advance. Feedback control is performed so as to reciprocate at a moving speed along the speed curve. This feedback control is performed by changing the direction and current value of the drive current supplied to the motor coil of the linear motor by the control unit, or the start / end timing of the drive current. When performing a printing operation, while the print head unit is reciprocating, the printing paper is transported in a direction orthogonal to the reciprocating movement direction, and the ink ribbon is positioned on the printing paper further thereon. By printing the needle pins from the print head unit on the printing paper, the ink is transferred to the printing paper, thereby performing printing.

[0005] In short, the section in which the print head unit reciprocates is occupied by a central section of the print section in which a printing operation is performed during constant-speed movement, and a section in which both ends of the reciprocating section are occupied by a reversing operation. It is divided into a paper feed section in which a paper feed operation is performed. On the other hand, the reversing section in which the reversing biasing force by the spring acts occupies the entire area near both ends of the reciprocating movement section including the paper feeding section. However, since the reversing biasing force by the spring also acts in the printing section, the reversing section and the reversing section are printed. The sections are provided so as to interfere with each other and partially overlap.

That is, the print head unit is controlled as follows. When performing the continuous line-by-line printing operation, the print head unit moves from the printing section to the reversing section, changes direction, and then moves from the reversing section to the other reversing section via the printing section again. Repeated.
At this time, the paper feeding operation is performed while the print head unit is being inverted in the paper feeding section near both ends even in the reversing section. On the other hand, when the print head unit is inverted, the paper is not always fed at a fixed length, but may be fed longer than usual, or the print command of the next line may not be sent. . At this time, the print head unit causes the linear motor to generate a driving force opposing the reversing biasing force of the spring, is retracted to a position beyond the reversing biasing force, and is temporarily stopped. After that, the reciprocating movement of the print head unit is started again in response to the completion of the paper feeding operation and the reception of the print command, so that the operation can be performed quickly even if the paper feeding or the delay of the print command is longer than usual. It is configured.

[0007]

However, when the print head unit is continuously inverted, retracted, stopped, or started, the print head unit must be controlled in advance due to variations in the dynamic characteristics of the spring and fluctuations in the driving force of the linear motor that depend on temperature changes. There is a problem that the print head unit cannot be uniquely moved along the determined speed curve.

For example, FIG. 8 is an explanatory diagram for explaining conventional inversion, retreat, stop, and start control.
When the driving force of the linear motor decreases due to a rise in temperature, as shown by a portion C in the figure, the retracting operation (E) of the print head unit becomes insufficient, and the position (F) to be normally stopped is set. When the print head unit moves beyond the normal stop position and cannot be restarted from the normal stop position (G), the reciprocating movement operation is started again, and the moving speed is disturbed. In the case of the portion indicated by the symbol D,
Since the print head unit was restarted with almost no stop, it was not possible to escape from the printing section, and an operation error occurred.

[0009]

DISCLOSURE OF THE INVENTION Accordingly, the present invention has been conceived in view of the above-mentioned circumstances, and the print processing capability is reduced even when the print head unit is continuously inverted, retracted, stopped, and started. It is an object of the present invention to provide a printing device capable of stabilizing the operation without using the same.

In order to solve the above problems, the present invention takes the following technical measures.

That is, according to the first aspect of the present invention, there is provided a linear driving means for reciprocating the printing means in a predetermined direction, and a reciprocating movement of the printing means by the driving force of the linear driving means. A reversing biasing means for exerting a reversing biasing force on the printing means near both ends of the reciprocating movement section, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means. When the printing means is temporarily retracted to a position beyond the reversing biasing force and the printing means is restarted immediately after the retreat, the printing means is moved from the retreat stop position to a section where the reversing biasing force of the reversing biasing means is applied. A printing device is provided, which has control means for variably controlling the timing of feeding back.

According to a second aspect of the present invention, there is provided a linear driving means for reciprocating a printing means in a fixed direction, and a reciprocating movement of the printing means by the driving force of the linear driving means. A reversing biasing means for exerting a reversing biasing force on the printing means near both ends of the reciprocating movement section, wherein the linear driving means generates a driving force opposed to the reversing biasing force of the reversing biasing means. When the printing means is temporarily retracted to a position beyond the reversing biasing force and the printing means is restarted immediately after the retreat, the printing means is moved from the retreat stop position to a section where the reversing biasing force of the reversing biasing means is applied. A printing apparatus is provided, which has control means for variably controlling a drive current to be supplied to a linear drive means when feeding back.

According to a third aspect of the present invention, there is provided a linear driving means for reciprocating the printing means in a predetermined direction, and a reciprocating movement of the printing means by the driving force of the linear driving means. A reversing biasing means for exerting a reversing biasing force on the printing means near both ends of the reciprocating movement section, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means. When the printing unit is temporarily retracted to a position beyond the reverse biasing force, and then the printing unit in a stopped state is restarted, when the printing unit is retracted to the retracting stop position, the printing unit should be supplied to the linear driving unit. A printing device is provided, which has control means for variably controlling the duty of the drive current.

According to a fourth aspect of the present invention, there is provided a linear driving means for reciprocating the printing means in a predetermined direction, and a reciprocating movement of the printing means by the driving force of the linear driving means. A reversing biasing means for exerting a reversing biasing force on the printing means near both ends of the reciprocating movement section, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means. When the printing unit is temporarily retracted to a position beyond the reverse biasing force, and then the printing unit in a stopped state is restarted, when the printing unit is retracted to the retracting stop position, the printing unit should be supplied to the linear driving unit. A printing device is provided, which has control means for variably controlling the drive current itself.

According to a preferred embodiment, when the feed amount of the printing means is less than the predetermined amount, the control means repeatedly executes restarting of the printing means.

According to another preferred embodiment, the control means determines that an operation error has occurred if the restart of the printing means is not successful even after the predetermined number of restarts.

According to the first and second aspects of the present invention, when the printing unit is restarted immediately after the retreat, a driving force is generated in the linear drive unit to move from the retreat stop position to the reversal section where the reversing biasing force is applied. And the printing means are sent back. that time,
By starting the drive by applying a drive current to the linear drive means,
The timing of terminating the start-up can be changed according to the operating condition, or the drive current to be supplied to the linear drive means can be changed according to the operating condition. Therefore, when continuously inverting, retreating, stopping, and starting the printing unit, even if the driving force of the linear driving unit fluctuates due to the variation in the dynamic characteristics of the inverting urging unit or the temperature change, at that time, In this case, appropriate control can be performed on the linear drive means in accordance with the situation described above, and the printing operation accompanying the reciprocating movement of the printing means can be promptly restarted to stabilize the operation without lowering the printing processing ability.

According to the third and fourth aspects of the present invention, when the printing unit is temporarily retracted, the duty of the driving current to be supplied to the linear driving unit is changed according to the operating condition, or the driving current itself is changed. Can be changed according to the operation situation. Therefore, when continuously inverting, retreating, stopping, and starting the printing unit, even if the driving force of the linear driving unit fluctuates due to the variation in the dynamic characteristics of the inverting urging unit or the temperature change, at that time, In this case, appropriate control can be performed on the linear drive means in accordance with the situation described above, and the printing operation accompanying the reciprocating movement of the printing means can be promptly restarted to stabilize the operation without lowering the printing processing ability.

As described above, the printing means is continuously inverted,
The control of the linear drive unit when retracting, stopping, and starting can be repeatedly performed a predetermined number of times when the feeding amount of the printing unit is less than a predetermined amount, and the printing unit is fed back by a predetermined amount within the predetermined number of times. In this case, the printing operation associated with the reciprocating movement of the printing means can be resumed as a normal operation without causing an operation error.

Other features and advantages of the present invention will become more apparent from the following description of embodiments of the invention with reference to the accompanying drawings.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a schematic view showing a schematic structure of an embodiment of a printing apparatus according to the present invention. In addition,
The invention of the present application has a feature in the control of the linear motor when the print head unit that is reciprocating is turned over, retracted, stopped, and started. Description is omitted.

As shown in FIG. 1, the printing apparatus includes a print head unit 1 and a print head unit 1 as printing means for performing a printing operation while reciprocating along a print line direction S.
, A belt / pulley mechanism 3 for transmitting the driving force of the linear motor 2 to the print head unit 1 while reversing the driving force, and freely moving the print head unit 1 along the print line direction S. A pair of elastic springs 5A and 5B as reversing urging means, which are guided and inserted into the fixing shaft 4 and apply reversing urging force when the print head unit 1 reciprocates, print in the reciprocating section. It comprises a linear encoder 6 for detecting the displacement of the head unit 1 and the like. The printing apparatus includes a microcomputer, which will be described later, for controlling on / off of a drive current supplied to the linear motor 2 in addition to mechanical components, and the microcomputer controls the operation of the entire printing apparatus. Controlled. The printing apparatus has a built-in thermistor as a component not shown in FIG.

FIG. 2 is a side view of the linear motor 2 seen from the side, and FIG. 3 is a top view of the linear motor 2 seen from the top, as shown in these figures. The linear motor 2 includes a pair of fixed scales 2A and 2B in which a plurality of permanent magnets G are arranged in a straight line and integrated.
A movable element 2C, which is inserted between the fixed scales 2A and 2B and to which a plurality of coils C are attached, is provided. The mover 2C generates a moving magnetic field in accordance with the drive current flowing through the coil C, and the moving magnetic field acts on the permanent magnets G on the fixed scales 2A, 2B, so that the moving magnetic field is generated between the fixed scales 2A, 2B. Move linearly. As shown in FIG. 3, the mover 2 </ b> C includes a constant-speed coil C <b> 1 that is mainly energized when moving at a constant speed, and an inverting coil C <b> 2 that is mainly energized when changing the moving direction. Is provided. By performing feedback control using the drive current supplied to these coils C1 and C2 as a control amount, the mover 2C
Reciprocate while repeating constant speed / reversal motion.

Turning to FIG. 1 again, such a mover 2C includes a connecting rod 3A and a belt pulley mechanism 3C.
While being connected to the print head unit 1 through
The movable stoppers 5C and 5D, which are guided and inserted into the fixed shaft 4 for pressing and releasing the elastic springs 5A and 5B against the print head unit 1, are also directly connected via the connecting rod 3A. Therefore, the print head unit 1
Reciprocates in the direction opposite to the reciprocating direction of the mover 2C, and at the same time, the movable stoppers 5C and 5D
It is configured to reciprocate in the same direction as the mover 2C. Therefore, the mover 2C also serves as a counter balancer for the print head unit 1 that moves reciprocally.

More specifically, the printing apparatus according to the present embodiment prints on a printing paper (not shown) such as a continuous form by a dot impact method. A large number of needle pins (not shown) are mounted in a state of being arranged in a matrix along a direction orthogonal to the transport direction F of the printing paper. When the print head unit 1 reciprocates along a print line direction S perpendicular to the print paper transport direction F, the print head unit 1 selectively ejects a needle pin from above an ink ribbon (not shown) toward the print paper. A printing operation is performed, and as a result, printing for one line is performed collectively. Such a printing operation is performed when the print head unit 1 moves at a constant speed in the reciprocating movement section, and when the print head unit 1 moves in the reverse direction, the printing paper is fed.

That is, the section in which the print head unit 1 reciprocates occupies a central portion thereof and performs a printing operation during constant-speed movement, and the other section occupies the both ends of the reciprocating section during reversal operation. And a paper feed section in which a paper feed operation is performed. On the other hand, the reversing section in which the reversing biasing force of the elastic springs 5A and 5B acts occupies the entire area near both ends of the reciprocating section including the paper feeding section. However, the reversing biasing force by the elastic springs 5A and 5B is also applied in the printing section. From acting
The inversion section and the printing section are provided so as to interfere with each other and partially overlap. The movement of the print head unit 1 in such a reciprocating section will be described later in detail.

FIG. 4 is a block diagram of a microcomputer built in the printing apparatus according to the present embodiment. As shown in FIG.
0, a ROM 11, a RAM 12, and an interface 13 are mutually connected by a bus line. The linear motor 2, the linear encoder 6, the thermistor 7, and the like are connected to the interface 13.

The MPU 10 controls a reciprocating operation of the print head unit 1 by controlling a drive current to be supplied to the coils C1 and C2 of the linear motor 2 in addition to a printing operation and a paper feeding operation by the print head unit 1. . More specifically, the MPU 10 controls the linear motor 2 as a control target with the drive current as a control amount, and prints based on the displacement sequentially detected via the linear encoder 6 when the print head unit 1 reciprocates. The moving speed of the head unit 1 is calculated, and feedback control is performed using the moving speed as a target change amount. At this time, when the MPU 10 reverses the print head unit 1 in the paper feeding section near both ends even in the reversing section, the MPU 10 simultaneously controls the paper feeding operation.

On the other hand, when the print head unit 1 is reversed, the paper is not always fed at a fixed length, but is fed longer than usual or when a print command of the next line is sent. May not come. At this time, the MPU 10 causes the linear motor 2 to generate a driving force opposing the reversing biasing force of the elastic springs 5A and 5B to a position where the reversing biasing force does not reach (hereinafter, referred to as a “retreat stop position”). The print head unit 1 is retracted and temporarily stopped.
Thereafter, the MPU 10 restarts the reciprocating operation of the print head unit 1 in response to the completion of the paper feeding operation or the reception of the print command, so that the MPU 10 can quickly perform the reciprocating operation even if the paper is fed longer than usual or the delay of the print command. Has been resumed.

The ROM 11 stores control programs and parameters to be executed by the MPU 10. RAM
Reference numeral 12 is used as a work area of the MPU 10 or the like.
The interface 13 functions as an input / output contact for the MPU 10. The linear encoder 6 outputs, in addition to the detection signal S1 corresponding to the displacement of the print head unit 1, inverted position detection signals S2 and S3 indicating that the print head unit 1 has reached the inverted section. The constant speed drive current D1 is supplied to the constant speed coil C1 of the linear motor 2, while the reverse drive current D2 is supplied to the reverse coil C2. The thermistor 7 detects the ambient temperature inside the device and transmits this to the MPU 10.

The detailed operation of the microcomputer having such a configuration will be described later. However, the microcomputer inverts, retracts, and stops the print head unit 1 in response to a paper feed or a print command delay longer than usual. , To start
In order to operate the print head unit 1 with high accuracy even by variations in the dynamic characteristics of the elastic springs 5A and 5B and fluctuations in the driving force of the linear motor 2 depending on changes in temperature, the timing and timing of the print head unit 1 can be appropriately adjusted according to the situation at that time. The linear motor 2 is controlled while changing the control amount.

FIG. 5 shows the inversion, retreat,
FIG. 4 is an explanatory diagram for explaining stop and start control, and when performing a continuous line-by-line printing operation as indicated by reference numeral A in this figure, the print head unit 1 moves from a printing section to a reversing section. After the direction change, the printing section moves from the reversing section to the other reversing section via the printing section again, and by repeating such an operation, the printing operation is performed while reciprocating. At this time, the paper feeding operation is performed during the reversal of the print head unit 1 in the paper feeding section in which the acceleration and deceleration is performed according to the reversing biasing force of the elastic springs 5A and 5B even in the reversing section.

On the other hand, as shown by the symbol B in FIG.
When reversing, retracting, stopping, and activating the print head unit 1 during reciprocation, the MPU 10 temporarily retracts the print head unit 1 to a retreat stop position where the reversing biasing force of the elastic springs 5A, 5B does not act to stop. Then, a driving force opposing the reversing biasing force is generated from the linear motor 2 to apply a braking force to the print head unit 1 during reversal (E).
Then, the print head unit 1 is brought into a state in which the print head unit 1 stays at the evacuation stop position until a paper feed operation or a print command of the next line is received (F). Thereafter, when the paper feeding operation is completed or a print command is received, the reciprocating operation of the print head unit is started again (G). At this time, the linear motor 2 generates a driving force corresponding to the print head unit 1 so that the print head unit 1 is fed back from the retracted stop position to the paper feed section where the reverse biasing force of the elastic springs 5A and 5B is relatively strongly applied. The drive current to be supplied to the coils C1 and C2 is controlled.

According to the above-described series of control procedures, the print head unit 1 can be stably inverted, retracted, stopped, and started, and a normal operation can be performed. However, in a situation where the dynamic characteristics of the elastic springs 5A and 5B fluctuate or the temperature inside the device rises due to heat generated by continuous operation and the driving force of the linear motor 2 fluctuates greatly, as described above, FIG. The following problems occur. Therefore, in the present embodiment, the case where the print head unit 1 is continuously inverted, retracted, stopped, and started, and the completion of the paper feeding operation and the print command immediately after the reciprocating print head unit 1 is retracted. When the print head unit 1 is restarted in response to the situation, the drive current is applied to the linear motor 2 to change the timing of starting the start or the timing of terminating the start according to the situation, and the print head unit 1 is stopped. The timing of feeding back from the position to the paper feed section is variably controlled. At the same time as performing variable control of the timing, or independently of the timing, when the print head unit 1 is fed back from the retraction stop position to the paper feed section, the value of the drive current to be supplied to the linear motor 2 is changed. Is controlled so as to be changed according to.

Further, the print head unit 1 which is moving back and forth
When the print head unit 1 is temporarily retracted, the duty of the drive current to be supplied to the linear motor 2 or the value of the drive current is changed according to the situation, so that the operation of keeping the print head unit 1 at a predetermined retract stop position is performed. Has stabilized.

Furthermore, if the print head unit 1 does not completely return to the paper feed section even with the above control, the subsequent reciprocating movement cannot be performed along a normal speed curve. In such a case, 1
If the same control is repeatedly performed a predetermined number of times as a retry operation instead of determining an operation error only once, and if the print head unit 1 can be returned to the paper feed section within the predetermined number of times, the operation error Can be handled as a normal operation without performing the above operation. According to this, it is possible to avoid as much as possible an operation error caused by reversing, retracting, stopping, and starting the print head unit 1.

Next, a control operation for reversing, retracting, stopping, and starting the print head unit 1 will be described mainly with reference to flowcharts.

FIG. 6 is a flowchart showing an example of an interrupt control process when the print head unit 1 is reversed, retracted, stopped, and started. Note that this interrupt control process is executed when the paper feed amount is longer than usual, or when the printing operation cannot be started because the print command of the next line is delayed from the reciprocating movement operation, and the print head unit 1 is reciprocated. This is a process for temporarily changing from a state in which the operation is performed to a state in which the operation is stopped. Further, the position of the print head unit 1 in the reciprocating section is sequentially detected via the linear encoder 6.

First, upon receiving the interrupt command, the MPU 10 moves the reciprocating print head unit 1 from the printing section to the paper feeding section, and further changes the direction from the paper feeding section to the direction toward the printing section. Control is performed (S1). This inversion control is performed by appropriately controlling the drive current supplied to the linear motor 2, and corresponds to the first half of the portion B just before the portion E shown in FIG. When performing the reversing control, the paper feeding operation is controlled at the same time.

When the print head unit 1 starts to shift from the paper feed section to the print section, the MPU 10
The evacuation control is started (S2). This retraction control corresponds to the portion E in FIG. 5, and the linear motor 2 generates a driving force opposing the reversing biasing force of the elastic springs 5A and 5B, and applies a braking force to the print head unit 1 during reversal. Done for. When the retraction control is sufficiently performed, the print head unit 1 is temporarily stopped at the retraction stop position indicated by the dashed line in FIG. This corresponds to the portion F in FIG.

Immediately after the start of the evacuation control, the MP
U10 monitors whether or not the paper feeding operation that caused the start of the interrupt control processing has been completely completed (S10).
3). When the cause of starting the interrupt control process is a delay of the print command, the MPU 10 monitors whether or not the print command has been received.

At the point immediately after the start of the evacuation control, if it is detected that the paper feeding operation is completely completed or that a delayed print command is received (S3: YES), the MPU
10 starts the restart control to reciprocate the print head unit 1 again (S4). This restart control means that the print head unit 1 is fed back from the evacuation stop position to the paper feed section where the reversing biasing force of the elastic springs 5A and 5B is relatively strongly applied, and the print head unit 1 is moved at a constant speed by the reaction. This is performed in order to push the print section into the printing section, and corresponds to the portion G in FIG.

At this time, depending on the state immediately after the evacuation, the restart control may be started from a state where the print head unit 1 is not completely stopped.
The temperature inside the apparatus may increase due to the variation of A and 5B and the continuous reciprocating movement before that, and a situation may occur in which a sufficient driving force cannot be obtained from the linear motor 2. Therefore, the MPU 10 changes the timing at which the restart control is terminated according to the position of the print head unit 1 sequentially detected via the linear encoder 6, the temperature detected via the thermistor 7, and the like. (S5). The timing at which the restart control ends is changed, for example, from 20 ms to 30 ms with reference to the restart start time. In this case, the current value of the drive current supplied to the linear motor 2 may be changed. As a result, the print head unit 1 at the evacuation stop position can escape from the printing section, and the linear motor 2 can generate a driving force enough to reliably reach the paper feeding section.

After executing the restart control as described above, the MPU 10 checks whether the print head unit 1 has escaped from the printing section and has reached the paper feed section (S).
6).

If the print head unit 1 has escaped from the printing section (S6: YES), the MPU 10 ends this interrupt control processing and returns to the processing related to the original reciprocating movement operation. Thus, the print head unit 1 restarts the printing operation while moving at a constant speed in the printing section via the driving force from the linear motor 2.

On the other hand, in S6, when the print head unit 1 cannot escape from the printing section even by the restart control (S6: NO), the MPU 10 continues until the number of retries reaches a predetermined number (S7: NO). The process returns to S4 to perform the restart control repeatedly.

In S7, when the number of retries reaches a predetermined number (S7: YES), the MPU 10 determines that an operation error cannot be returned to a normal operation (S8), gives a notification to that effect, and executes this interrupt control processing. Finish.

In S3, immediately after the start of the evacuation control, if the paper feeding operation is not completed or a delayed print command cannot be received yet (S3: NO), the MPU 10
Performs stop control (S9). This stop control, as described above, refers to control in a state where the print head unit 1 stays at the retraction stop position.

After that, similarly to S3, the MPU 10 detects that the paper feeding operation has been completely completed or that a delayed print command has been received (S10:
YES), after performing the restart control (S11), proceed to S6.

In S10, if the paper feeding operation is not completed or a delayed print command cannot be received yet (S10: NO), the MPU 10 returns to the stop control in S9.

FIG. 9 is an explanatory diagram for explaining the operation suitable for the portion C in FIG. 8. In summary with reference to FIG. 9, when the position of R2 is detected as shown in the portion C. A right edge signal is generated from the linear encoder 6. Then M
The PU 10 enters the control of the retreat operation (E), and drives the linear motor 2 for the section E so as to apply a force in the reverse direction to the print head unit 1. Originally, it is ideal to stop the print head unit 1 while maintaining the balance at the retraction stop position of R3. However, the print head unit 1 may be jumped to the position of R4 by the elastic springs 5A and 5B for the above-described reason. . The distance between R3 and R4 also changes depending on the environment such as mechanical conditions and temperature.

Next, during the stop period (F) before printing is started, the constant-speed coil C1 is driven to move the print head unit 1 toward the position of R3 which contacts the elastic springs 5A and 5B. However, since the thrust by the constant velocity coil C1 is small, it does not reach the position of R3 immediately. When restart (G) is started at a position that does not reach R3, the print head unit 1 moves along a movement locus such as a curve Cr, and the escape distance (H) from the print section R2-R2 is shortened. The printing quality will be degraded.

Then, based on the position information of the print head unit 1 obtained from the linear encoder 6, the MPU 1
0 extends the end time of the timing operation due to the restart (G), and sets the timing operation to (G ′) as shown in FIG. Alternatively, the drive current supplied to the linear motor 2 is increased without changing the timing operation due to the restart as (G). Alternatively, both are performed. In this way, the escape distance (H) is extended and R1
, The linear motor 2 is controlled so as to return the print head unit 1 to the position of the print head unit 1. Thus, the movement trajectory of the print head unit 1 becomes a trajectory indicated by a two-dot chain line curve Cr ', and the print head in the print section R2-R2. The change in the speed of the unit 1 can be prevented.

Therefore, according to the printing apparatus which performs the reversing, retreating, stopping, and starting control in the procedure shown in FIG. 6, the driving force of the linear motor 2 is reduced due to the variation in the dynamic characteristics of the elastic springs 5A and 5B and the temperature rise. Even in the situation where the print head unit 1 is lowered, appropriate control can be performed on the linear motor 2 according to the situation at that time.
A series of operations such as reversing, retreating, stopping, and starting can be stabilized without lowering the printing processing capability by immediately restarting the printing operation accompanying the reciprocating movement of.

Next, another embodiment will be briefly described with reference to a flowchart.

FIG. 7 is a flowchart showing another example of the interrupt control process when the print head unit 1 is reversed, retracted, stopped, and started. A series of control procedures shown in FIG. 7 are exactly the same as those in FIG. 6 except for S21 shown in the flowchart in FIG. 7, and are denoted by the same step numbers as those in FIG. The only difference is that S21 is provided,
This point will be mainly described below.

In S3, if the paper feeding operation is completely completed immediately after the start of the evacuation control, or if a delayed print command is received (S3: YES), the elastic springs 5A and 5B are also used in this case. And the temperature inside the apparatus rises due to the continuous reciprocating movement before that, and a situation may occur in which a sufficient driving force cannot be obtained from the linear motor 2. Therefore, MPU
Reference numeral 10 denotes the duty of the drive current supplied to the linear motor 2 at the start of the stop control according to the position of the print head unit 1 sequentially detected via the linear encoder 6 and the temperature detected via the thermistor 7. Is changed (S21). The duty of the drive current is a ratio of the number of drive pulses per unit time, and is changed, for example, from 50% to 70%. In this case, the current value of the drive current supplied to the linear motor 2 may be changed. This allows
The linear motor 2 can generate a driving force that keeps the print head unit 1 gradually approaching and stopping at a predetermined evacuation stop position. Thereafter, the MPU 10 executes S4
Proceed to.

FIG. 10 is an explanatory diagram for explaining an operation suitable for the portion D in FIG. 8. In summary with reference to FIG. 10, as shown in the portion D, the operation is stopped from the evacuation (E). (F)
If the print head unit 1 is greatly skipped from the target stop position (R3) immediately after the shift to the above, even if the restart (G) is performed as it is, the print head unit 1 is moved to the print section R.
2-Because it is not possible to escape from R2, an error occurs.

In such a case, the print head unit 1 is moved closer to the target stop position (R3) as much as possible in order not only to vary the restart end timing but also to minimize the skipping of the print head unit 1. As described above, the MPU 10 variably controls the duty of the drive current supplied to the constant-speed coil C1 at the start of the stop control (F).
Then, by performing the same control as that described for the part C shown in FIG. 9 described above, it is possible to avoid an operation in which the print head unit 1 cannot escape from the print section R2-R2 and an error occurs.

Further, even if the escape from the printing section R2-R2 fails, the error is not immediately detected, and the occurrence of the error can be minimized by performing the retry control again.

Therefore, according to the printing apparatus which performs the reversing, retreating, stopping, and starting control in the procedure shown in FIG. 7, the linear motor is controlled by the variation in the dynamic characteristics of the elastic springs 5A and 5B and the temperature rise during the retreat control. 2, the appropriate control can be performed on the linear motor 2 according to the situation at that time, and the printing operation accompanying the reciprocating movement of the print head unit 1 is controlled by the retract control. Even after the stop due to the above, a series of operations such as reversing, retreating, stopping, and starting can be stabilized without lowering the print processing capability by immediately restarting.

The present invention is not limited to the above embodiment.

For example, the printing method is not limited to the dot impact method and can be applied to an ink jet method.

The means for reciprocating the print head unit is not limited to a linear motor. If the print head unit can be moved in a reciprocating linear motion by feedback control, a normal rotary drive type motor can be used. There may be.

[0066]

As described above, according to the present invention, for example, when the print head unit is continuously inverted, retracted, stopped, and started, the linear motor is driven by variations in the dynamic characteristics of the elastic spring and temperature changes. Even in situations where the driving force fluctuates, appropriate control can be performed on the linear motor according to the situation at that time, and the printing operation accompanying the reciprocating movement of the print head unit is immediately restarted for printing. The operation can be stabilized without lowering the processing capability.

[Brief description of the drawings]

FIG. 1 shows an embodiment of a printing apparatus according to the present invention.
It is the schematic which shows the schematic structure.

FIG. 2 is a side view of the linear motor viewed from the side.

FIG. 3 is a top view of a state where the mover of the linear motor is viewed from above.

FIG. 4 is a block diagram of a microcomputer built in the printing apparatus according to the embodiment.

FIG. 5 is an explanatory diagram for describing inversion, retreat, stop, and start control in the present embodiment.

FIG. 6 is a flowchart illustrating an example of an interrupt control process when the print head unit is reversed, retracted, stopped, and started.

FIG. 7 is a flowchart illustrating another example of the interrupt control process when the print head unit is reversed, retracted, stopped, and started.

FIG. 8 is an explanatory diagram for explaining inversion, retreat, stop, and start control in the related art.

FIG. 9 is an explanatory diagram for explaining an operation suitable for a portion C in FIG. 8;

FIG. 10 is an explanatory diagram for explaining an operation suitable for a portion D in FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 print head unit (printing means) 2 linear motor (linear driving means) 2A, 2B fixed scale 2C mover 3 belt pulley mechanism 4 fixed shaft 5A, 5B elastic spring 5C, 5D movable stopper 6 linear encoder 7 thermistor 10 MPU ( Control means) 11 ROM 12 RAM 13 interface C1 constant velocity coil C2 inversion coil

Claims (6)

[Claims] 1. A linear driving means for reciprocating a printing means in a predetermined direction, and when the printing means reciprocates by the driving force of the linear driving means, the printing means is provided near both ends of a reciprocating section. A reversing biasing means for exerting a reversing biasing force on the reversing means, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means to reverse the printing means. When the printing unit is temporarily retracted to a position beyond the urging force and the printing unit is restarted immediately after the retreat, the timing of sending the printing unit back from the evacuation stop position to the section where the reversing urging force of the reversing urging unit is applied is determined. A printing device comprising control means for variably controlling. 2. A linear driving means for reciprocating a printing means in a predetermined direction, and the printing means reciprocating by the driving force of the linear driving means, the printing means being provided near both ends of a reciprocating movement section. A reversing biasing means for exerting a reversing biasing force on the reversing means, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means to reverse the printing means. When the printing unit is temporarily retracted to a position beyond the urging force and the printing unit is restarted immediately after the retreat, when the printing unit is fed back from the evacuation stop position to the section where the reversing urging force of the reversing urging unit is applied. And a control unit for variably controlling a drive current to be supplied to the linear drive unit. 3. A linear drive means for reciprocating the printing means in a predetermined direction, and the printing means reciprocating by the driving force of the linear driving means, the printing means being provided near both ends of a reciprocating movement section. A reversing biasing means for exerting a reversing biasing force on the reversing means, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means to reverse the printing means. When the printing unit is temporarily retracted to a position beyond the urging force and then restarted in the stopped state, the duty of the drive current to be supplied to the linear driving unit is required when the printing unit is retracted to the retraction stop position. A control device for variably controlling the printing apparatus. 4. A linear driving means for reciprocating the printing means in a predetermined direction, and when the printing means reciprocates by a driving force of the linear driving means, the printing means is provided near both ends of a reciprocating section. A reversing biasing means for exerting a reversing biasing force on the reversing means, wherein the linear driving means generates a driving force opposing the reversing biasing force of the reversing biasing means to reverse the printing means. When the printing means is temporarily retracted to a position where the urging force does not reach, and then the printing means in a stopped state is restarted, when the printing means is retracted to the retraction stop position, the drive current itself to be supplied to the linear driving means is used. A printing device comprising control means for variably controlling. 5. The printing apparatus according to claim 1, wherein the control unit repeatedly restarts the printing unit when the feeding amount of the printing unit is less than a predetermined amount. 6. The printing apparatus according to claim 5, wherein the control unit determines that an operation error has occurred if the restart of the printing unit is not successful even after the predetermined number of restarts.