JP3333690B2 - Printer carriage motor control method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a carriage motor of a printer for printing by driving a carriage on which a print head is mounted by a carriage motor.

[0002]

2. Description of the Related Art FIG. 8 is a block diagram of a printer for printing by driving a carriage on which a print head is mounted by a carriage motor. A carriage 2 on which a print head 1 is mounted is fixed to a drive belt 4 wrapped around a drive pulley 31 fixed to a drive shaft of a carriage motor 3 and a driven pulley 32, and is a carriage motor composed of a stepping motor and the like. 3 drives the carriage 2
Is guided by the guide shaft 5 and reciprocates right and left along the platen 6. Printing on the medium P is performed by the print head 1 while the carriage 2 reciprocates. Reference numeral 7 denotes a reference position sensor (hereinafter, referred to as a reference position sensor) that outputs an ON-state detection signal by detecting the detection target piece 21 provided on the carriage 2. The carriage 2 is positioned at a predetermined reference position based on a detection signal of the reference position sensor 7.

When the printer is powered on, the carriage motor 3 is controlled based on a detection signal of the reference position sensor 7.
After driving the carriage 2, the carriage 2 is positioned at the reference position, and then waits for a print command given from a host device of the printer. When the printer receives a print command from a higher-level device, it drives the carriage motor 3 to perform printing with the print head 1 while reciprocating the carriage 2 left and right.

[0004]

In such a printer, the carriage motor 3 is driven and controlled based on the number of driving steps with the reference position as the origin.
During standby for a print command after the reference positioning process has been performed after the power is turned on, the carriage motor 3 is weakly excited and the drive shaft of the motor is fixed in order to hold the carriage 2 at the reference position. Therefore, in order to weakly excite the carriage motor 3, it is necessary to provide an additional circuit for weak excitation in the drive circuit, and while the print command is waiting (non-printing period), the printing operation is not performed. Therefore, useless electric power is consumed by the carriage motor 3, its driving circuit and the power supply circuit. When the power of the printer is turned on every time printing is performed and the power is turned off at the end of the printing operation, the non-printing period is shorter than the printing period during the power-on. Power consumption is negligible. However, for example, when the power is turned on for a long time, but the actual operation (printing operation) is performed irregularly (randomly), such as a printer built in a ticket vending machine for parking tickets, the printing period The non-printing period is much longer than that of the above, and the power consumption of the carriage motor 3 and the like during the above-described print command standby cannot be ignored. In addition, the heating of the weakly excited carriage motor 3 and the like may adversely affect the printer itself and the device incorporating the printer.
In addition, even if an attempt is made to perform maintenance (for example, replacing the ink ribbon) that requires moving the carriage while the print command is on standby, the carriage 2 is easily excited because the carriage motor 3 is weakly excited. I couldn't do it, and the work was difficult. The present invention has been made in view of such circumstances, and an object of the present invention is to provide a printer which does not need to weakly excite a carriage motor in a print command standby state.

[0005]

SUMMARY OF THE INVENTION The present invention relates to a carriage motor control method for a printer which performs printing by moving a carriage on which a print head is mounted by a carriage motor. After being positioned at the position, the carriage motor is de-energized to be in a print command standby state, and when the print command is received during the print command standby, the carriage motor is driven to set the position of the carriage to the It is determined whether or not the reference position is within an allowable range, if the determination result is affirmative, perform a printing operation based on the print command, if the determination of the reference position determination process is negative,
The printing operation is performed based on the print command after the carriage is positioned at the reference position, and after the printing operation is completed, the excitation of the carriage motor is released to put the print command in a standby state. I have. According to the above method, after positioning the carriage at the reference position,
While the print command is waiting until the print command is received, the carriage motor is de-energized. At the time when the print command is received, it is determined whether the carriage is positioned within an allowable range with respect to the reference position. If the result of the determination is negative, the carriage is positioned at the reference position before printing. I do. Note that a motor for driving a carriage on which a print head is mounted is generally called a carriage motor or a spacing motor, but in this specification, it is unified with the term carriage motor.

[0006]

Next, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, the method of the present invention will be described by roughly dividing it into two processes. One is an initialization process for positioning the carriage at a reference position and waiting for a print command after the printer is turned on, and the other is to perform printing after receiving a print command while the power is turned on. At the same time, it is a print process for waiting for a print command. Note that the configuration of the mechanical part of the printer is the same as that of the related art, and therefore the description will be given with reference to FIG.

FIG. 1 is a block diagram showing a printer to which the method of the present invention is applied. The printer 10 includes a CPU 11
A ROM 12 for holding a control program, etc., a RAM 13 for providing a carriage motor movement check flag (hereinafter simply referred to as a check flag) FLG, a reference position sensor counter CN, and a work area, and font data to be provided to the print head 1. RO that retains
M14, a motor control circuit 15 for controlling the carriage motor 3, a print head control circuit 16 for controlling the print head 1, and an I / O port 17 for inputting a detection signal from the reference position sensor 7. And an interface circuit (hereinafter, referred to as an I / F circuit) 18 for performing data communication with the host device 20. A drive circuit for driving the carriage motor 3 and a power supply circuit thereof are not shown.

FIG. 2 is a flowchart of an initialization process performed immediately after power-on according to the above configuration. When the power of the printer 10 is turned on, an initial value of the phase data is output from the CPU 11 to the motor control circuit 15 (step ST1). This initial value is the same value as the phase data supplied to the carriage motor 3 when the power supply was turned off immediately before, and is held in the RAM 13.

Next, the CPU 11 determines whether or not the reference position sensor 7 detects the detection target 21 of the carriage 2 based on the detection signal of the reference position sensor 7 input via the I / O port 17. Is determined (step ST2).

If the determination result of step ST2 is affirmative ("Y"), the CPU 11
, A drive signal for driving the carriage motor 3 in the forward direction is given (step ST3), and it is determined whether or not the detected piece 21 of the carriage 2 is detected by the reference position sensor 7 (step ST4). Is affirmative ("Y"), the process proceeds to step ST3, and if step ST4 is negative ("N"), the process proceeds to step ST5. That is, the carriage motor 3 is driven in the forward direction until the detected piece 21 of the carriage 2 is no longer detected by the reference position sensor 7. At this time, as shown in FIG. 3A, the end 21a of the detected piece 21 of the carriage 2 on the reverse direction R side is at a position just deviated from the detection position indicated by the dashed line in the reference position sensor 7.

Next, whether the carriage 2 is detected by the reference position sensor 7 in step ST4 or not is determined in step ST4.
If negative ("N") at 2, the CPU 11 gives a drive signal for driving the carriage motor 3 in the reverse direction to the motor control circuit 15 (step ST5), and the carriage 2 is detected by the reference position sensor 7. It is determined whether or not there is (step ST6), and step ST6 is negative ("N").
If so, the process proceeds to step ST5, and if step ST6 is affirmative ("Y"), the process proceeds to step ST7. That is, the detected piece 21 of the carriage 2 is
Until it is detected, the carriage motor 3 is driven in the reverse direction. When the reference position sensor 7 is turned ON, the end 21a of the detected piece 21 of the carriage 2 on the reverse direction R side exactly matches the detection position of the reference position sensor 7, as shown in FIG. It is in the position that I did.

Next, the CPU 21 drives the carriage motor 3 in the reverse direction by a specified amount (described later in detail) (step ST7). When the carriage motor 3 is driven by the specified amount in the reverse direction, as shown in FIG.
The center position of the detection target piece 21 of the carriage 2 is at a position that exactly matches the detection position of the reference position sensor 7. That is, the specified amount corresponds to の of the dimension L of the detected piece 21 in the moving direction. Then, the phase data of the carriage motor 3 at that time, that is, the phase data when the reference positioning of the carriage 2 is completed is stored in the RAM 13 (step ST8), the excitation to the carriage motor control circuit 15 is released, and the carriage motor 3 is released. The printer is in a non-excited state and waits for a printing process (step ST9). As a result, the printer 10 shifts to a print command standby state. In the process of FIG. 2, the carriage motor 3 is driven in a forward direction and a reverse direction by self-starting (a driving method in which speed control is not performed). At this time, the carriage motor 3 may of course be driven by a normal speed control program.

The above-described reference positioning operation will be further described with reference to FIG. FIG. 4B is a characteristic diagram showing the carriage position X on the horizontal axis and the sensor output S of the reference position sensor 7 on the vertical axis. The sensor output S is ON (“H”) when the detection target piece 21 is detected, and is OFF (“L”) when detection is not performed. Therefore, when the sensor output S is switched from OFF to ON, the carriage position Xa is recognized (FIG. 2: affirmative (“Y”) in step ST6), and the carriage 2 moves from the position Xa in the reverse direction R.
(FIG. 2: Step ST)
7) By doing so, it is positioned at the reference position Xhp. In other words, the reference position Xhp is set such that the sensor output S changes from OFF to O.
Note that the position is set not to the position Xa at which the position is switched to N, but to a position moved in the opposite direction by the specified amount L / 2 from the position Xa.

FIG. 4A is a characteristic diagram showing the carriage position X on the horizontal axis and the carriage moving speed V on the vertical axis, and corresponds to the horizontal axis in FIG. 4B. When the carriage 2 is moved in the forward direction F by the carriage motor 3, the area A1 is accelerated from the reference position Xhp, the area A2 is moved at a constant speed, the area A3 is decelerated, and the right end is moved. It stops at the stop position Xe. On the other hand, when moving in the reverse direction R, the area A3 is accelerated from the stop position Xe, and the area A3 is accelerated.
2 is moved at a constant speed, and the area A1 is decelerated and stopped at the reference position Xhp. That is, the reference position Xhp is a reference origin when the drive control of the carriage motor 3 is performed. The printing operation by the print head 1 is performed in an area A2 that is moved at a constant speed in the forward direction F and the reverse direction R as in the related art.

The processing of steps ST1 to ST7 in FIG. 2 is substantially the same as the reference positioning operation performed by the conventional method. However, in the conventional method, step S
After T7, the carriage motor 3 is weakly excited to wait for the printing process.
The difference is that the phase data is stored in the RAM 13 and the excitation of the carriage motor 3 is released as shown in T8 and ST9. Therefore, since the carriage motor 3 is in a non-excited state, power is not supplied to not only the carriage motor 3 but also its driving circuit and power supply circuit, so that power consumption can be greatly reduced, and No heat is generated.

Next, the printing process executed after the above-described initialization process will be described with reference to the flowcharts of FIGS. First, a description will be given with reference to the flowchart of FIG. The CPU 11 is waiting for a print command from the host device 20 (step ST10). When the print command is received (Yes in step ST10 (“Y”)), the reference position sensor 7 causes the detected piece 21 of the carriage 2 to be detected. It is determined whether or not detection has been performed (ON) (step ST11). If step ST11 is affirmative (“Y”), that is, if the carriage 2 has not been manually moved, R
The reference position sensor counter CN of AM13 is cleared (step ST12). This reference position sensor counter C
N is used to check how much the carriage 2 deviates from the reference position.

Next, at step ST8 in FIG.
The phase data stored in M13 is output (step S13).
T13), the check flag FLG of the RAM 13 is set to ON (step ST14).

Next, the carriage motor 3 is accelerated in the forward direction (step ST15). This acceleration operation
This corresponds to the area A1 shown in FIG. Then, it is determined whether the check flag FLG is ON or OFF (step ST16).

At step ST14, the check flag FLG
Is set to ON, then it is determined whether or not the reference position sensor 7 is ON (step ST17), and if not, the process proceeds to step ST19. If affirmative ("Y"), the reference position sensor counter CN is incremented by 1 (step ST18), and it is determined whether or not the acceleration operation has been completed (step ST19).

Since the number of steps for performing the acceleration operation of the carriage motor 3 is determined in advance by the motor control program, the determination in step ST19 may be made based on whether or not the number of steps has been reached. Step S
At T19, if the acceleration operation has not been completed, step S
The process proceeds to T15 to continue the acceleration operation. That is,
By executing the loop of steps ST15 to ST19, the counter CN is incremented by one while the reference position sensor 7 is detecting the detected piece 21, and the counting of the counter CN is stopped when the detection is stopped. ing.

If the acceleration operation has been completed (step ST
In step 19, affirmative ("Y"), it is determined whether the check flag FLG is ON or OFF (step ST20). here,
Since it has been set to ON in step ST14, it is next determined whether or not the count value of the reference position sensor counter CN (corresponding to the number of steps of the carriage motor 3) is within a predetermined allowable range (step ST21).

The permissible range corresponds to a permissible amount for determining whether or not the moving amount is within a negligible range when the carriage 3 is moved during standby.
It is set so as to be negligible and to have a negligible effect on print quality (print shift). The reason why the allowable range is made larger than the specified value L / 2 is that, in consideration of the backlash or the like of the carriage moving mechanism, the actual moving amount may be slightly larger than the specified value L / 2.

If the determination in step ST21 is negative ("N"), that is, if it is determined that the carriage 3 has been moved out of the allowable range from the reference position Xhp during standby, the carriage motor 3 is once decelerated and stopped. (Step ST
22), the process proceeds to step ST30 in FIG. On the other hand, if affirmative ("Y") in step ST21, that is, if it is determined that the carriage 3 has not been moved from the reference position Xhp during standby, the process proceeds to step ST40 in FIG.

At step ST30 in FIG. 6, C
The PU 11 gives a command to the motor control circuit 15 to drive the carriage motor 3 in the reverse direction by self-starting. Then, it is determined whether or not the reference position sensor 7 is ON (step ST31). Step ST3 until the reference position sensor 7 is turned on (until the detected piece 21 is detected).
Repeat the loop of 0, ST31.

If the determination result of step ST31 is affirmative ("Y"), the carriage motor 3 is moved to the specified amount (2
/ L) in the reverse direction (step ST3)
2). That is, the same reference positioning operation as in step ST7 is performed. That is, steps ST30 to ST32
Thus, the reference positioning operation of the carriage 2 is performed again. Then, the process proceeds to step ST15 in FIG. 5 to execute the printing process. Therefore, if the carriage 2 is moved from the reference position to a position outside the permissible range for some reason while the carriage motor 3 is waiting for a print command in which the carriage motor 3 is not excited, the reference positioning operation of the carriage 2 is performed. Since printing is started, there is no possibility that printing deviation or the like occurs.

Next, continuing the description from step ST40 in FIG. 7, the carriage motor 3 is driven at a constant speed to execute the printing operation by the print head 1 (step ST4).
0). When the printing operation is completed, the carriage motor 3 is decelerated to drive the carriage 2 to the rightmost stop position Xe (FIG. 4).
(A)) and stop (step ST41). Then, the check flag FLG is turned off (step ST4).
2) It is determined whether or not the series of operations has been completed, that is, whether or not print data to be printed still remains (step ST43).

If the result of the determination in step ST43 is negative ("N"), there is print data to be printed.
The process proceeds to steps ST10 and ST11 in FIG. 5 to continue the printing operation. Note that when the printing operation is continued, the excitation of the carriage motor 3 is not released. Here, since the carriage 3 is at the rightmost stop position Xe, the reference position sensor 7 is OFF, and the process proceeds to step ST23 to determine whether the carriage motor 3 is not excited. If the determination result in step ST23 is negative ("N"), that is, if the carriage motor 3 is being excited, it is determined that a printing operation is being performed, and step ST1 is performed.
Then, the process proceeds to the acceleration driving of No. 5. However, the acceleration drive at this time is in the opposite direction.

Here, since the check flag FLG has already been turned off in step ST42, step ST16 is executed.
Is negative ("N"), and the result of step ST1 is
The acceleration operation in the reverse direction is performed by repeating the loop of 9, ST15, and ST16. This acceleration operation is performed in the region A of FIG.
It corresponds to 3.

When the acceleration operation is completed (step ST19)
Is affirmative ("Y") and the check flag FLG is in the OFF state, so the result of the determination in step ST20 is negative ("N").
Then, without executing the operation of determining the count value of the reference position sensor counter CN (step ST21), the process proceeds to step ST40 in FIG. 7 to perform printing while operating the carriage motor 3 in the reverse direction at a constant speed. .

When the printing operation is completed, step ST41 is performed.
The carriage 2 is decelerated and stopped, and the carriage 2 is moved to the reference position X.
hp. Then, the check flag FLG is set to O
FF (step ST42), it is determined whether or not the series of operations is completed (step ST43). If the determination result is negative ("N"), the process returns to step ST10 to wait for a print command. Then, the same printing process is continued.

On the other hand, if the determination result of step ST43 is affirmative ("Y"), that is, if the series of operations has been completed (if there is no print data to be printed), the carriage 2
Stores the phase data of the carriage motor 3 in the RAM 13 since it has returned to the reference position Xhp (step S
T44), the excitation of the carriage motor 3 is released (step ST45), and a print command is awaited. That is, FIG.
To the same state as when step ST9 of FIG. Therefore, in this print command standby state, if a print command is received, step ST10 in FIG.
Start with the action.

If the carriage 2 has shifted to the position where the reference position sensor 7 is turned off when the operation is started from step ST10 in FIG. 5, the determination result in step ST11 is negative ("N"). , Next step ST2
Since the determination of No. 3 is affirmative (“Y”), the carriage 2 is accurately positioned at the reference position by executing the same reference positioning processing as in steps ST1 to ST8 of FIG. 1 described above (step ST24). . Then, the process proceeds to step ST15 to execute a normal printing process. Therefore, even when the carriage 2 is moved from the reference position for maintenance such as replacement of the ink ribbon of the print head 1 while the carriage motor 3 is in a standby state for a print command that is not excited, the print command is received. In addition, since the carriage 2 is positioned at the reference position, printing can be performed without any problem.

The check flag FLG is set to 0 when the moving direction of the carriage 2 in the printing process is the forward direction, that is, the direction in which the carriage moves away from the reference position.
N, and is set to OFF when the carriage 2 is in the opposite direction, that is, when the carriage 2 approaches the reference position. That is, it is a flag for indicating the driving state of the carriage motor 3 during the printing process.

In the embodiment described above, when positioning the carriage 2 at the reference position, the reference position sensor 7 is turned on.
After that, the carriage 2 is moved by a specified amount (1/2 of the length L of the detection piece 21 of the carriage 2), but the specified amount is not limited to L / 2.

According to the above-described embodiment, immediately after the printer is powered on, the carriage 2 is positioned at the reference position Xhp, and then the excitation of the carriage motor 3 is released to enter a print command standby state. When the print command is received, the carriage motor 3 is driven to determine whether or not the position of the carriage 2 is within the allowable range with respect to the reference position Xhp. If the determination of the reference position determination process is negative, the carriage 2 is positioned at the reference position, and then the printing operation is performed based on the print command. Is released and the printer is in a print command standby state. Therefore, since the carriage motor is de-energized while the print command is waiting until the print command is received after positioning the carriage at the reference position, power consumption can be suppressed unlike the conventional method, Since there is no heat generated by the weak excitation, there is no possibility that the printer and the device incorporated therein will be adversely affected. Further, since it is not necessary to weakly excite the carriage motor while the print command is waiting, it is not necessary to provide a circuit for weak excitation in the drive circuit of the carriage motor, so that the cost can be reduced. In addition, since the carriage motor is in the non-excited state while the print command is waiting, it is possible to easily perform maintenance work that requires moving the carriage. Then, even if the carriage is moved until it deviates from the allowable range, printing is performed after positioning the carriage at the reference position, so that printing failure does not occur.

[0037]

As described above in detail, according to the method of controlling the carriage motor of the printer of the present invention, the carriage motor is de-energized while waiting for a print command. It is not necessary to add a circuit for weak excitation to the circuit, reducing costs and
Since power consumption can be suppressed and there is no heat generation due to weak excitation, there is no possibility of adversely affecting the printer and the devices incorporated therein. In addition, since the carriage motor is in the non-excited state while the print command is waiting, it is possible to easily perform maintenance work that requires moving the carriage. Then, even if the carriage is moved until it deviates from the allowable range, printing is performed after positioning the carriage at the reference position, so that printing failure does not occur.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a printer to which the method of the present invention is applied.

FIG. 2 is a flowchart of an initialization process showing an embodiment of the method of the present invention.

FIG. 3 is an explanatory diagram of an operation of a reference position sensor according to the embodiment.

FIG. 4 is a characteristic diagram showing a carriage moving speed with respect to a carriage position and an output of a reference position sensor in the embodiment.

FIG. 5 is a flowchart of a printing process according to the embodiment.

FIG. 6 is a flowchart of a printing process according to the embodiment.

FIG. 7 is a flowchart of a printing process according to the embodiment.

FIG. 8 is a configuration diagram of a printer that performs printing by moving a carriage.

[Explanation of symbols]

 Reference Signs List 1 print head 2 carriage 3 carriage motor 7 reference position sensor 10 printer 13 RAM FLG carriage motor movement check flag CN reference position sensor counter

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B41J 19/18-19/74

Claims (1)

(57) [Claims] 1. A method of controlling a carriage motor of a printer for printing by moving a carriage on which a print head is mounted by a carriage motor, wherein the carriage is positioned at a reference position immediately after power-on of the printer. When the print command is received while the print command is waiting during the print command standby, the carriage motor is driven so that the position of the carriage is within the allowable range with respect to the reference position. Is determined, and if the determination result is affirmative, the printing operation is performed based on the print command.If the determination of the reference position determination processing is negative, the carriage is positioned at the reference position. A printing operation is performed based on the printing command, and after the printing operation is completed, the excitation of the carriage motor is released. The carriage motor control method of the printer, characterized in that, to the print command wait state Te.