JPH07106658B2 - Printing start positioning method of print head in serial printer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a method of printing a character by character, that is, a method of determining a printing position of a first character of a so-called serial printer.

<Prior Art> In a serial printer, as a means for determining the first print start position, for example, a means for detecting the position of the carriage by an optical reading sensor and a servo motor to set the spacing amount of the carriage to determine the print position. There are things.

FIG. 4 is a schematic configuration diagram of a positioning mechanism using an optical reading sensor. The print head 20 moves to the left and right of the spacing path r along the spacing shaft 22 via the carriage 21. An optical reading sensor 23 including, for example, a light emitting diode and a light receiving transistor is provided at the left end of the spacing path r (the right end when the right end is a reference).
The sensor 23 is installed corresponding to the logical origin position, that is, the physical print position P of the first character. In other words, when the print head 20 is spaced by the movement of the carriage 21 and its position is read by the sensor 23, the print head 20 is set in correspondence with the print position P of the first character.

In the above positioning mechanism, as shown in the flowchart of FIG. 5, the movement of the carriage 21 turns the sensor 23 ON or OFF (Sa).
Is reversely moved to release the ON state by the sensor 23 (Sb), moved to the OFF position (Sc), and again moved to the sensor 23 (Sd). Then, when the sensor 23 is turned on (Se), it is set corresponding to the print position P of the first character.

On the other hand, when the servo motor is used, the rotation of the spacing motor and the spacing amount of the carriage are made to correspond to each other.
It determines the printing position of characters. FIG. 6 is a schematic configuration diagram showing the positioning mechanism of the conventional example, and FIG. 7 shows a flowchart for determining the printing position. That is, the spacing speed and spacing amount of the print head are set and controlled while feeding back the change in carriage movement through a timing slit or the like attached to the rotating shaft of the spacing motor. As shown in the figure, first, the carriage 31 having the print head 30 mounted thereon is moved along the spacing shaft 32 and brought into contact with the stopper 33. As a result, the print head 30 can be set correspondingly to the first character print position P that is defined relatively to the stopper 33. Then, the carriage 31 is spaced in the direction of the stopper 33 (Sf), and when the carriage 31 comes into contact with the stopper 33, the signal change indicating the change in movement is not fed back from the timing slit or the like (Sg). Since the feedback of this signal change is eliminated, the print head 30 is set to the first character print position P, and the print operation is then started.

As described above, there is also an easy method of detecting the physical left end or right end by maximizing the spacing amount without detecting the presence or absence of change feedback from the timing slit or the like.

<Problems to be Solved by the Invention> Among the above-mentioned positioning means, when an optical reading sensor is used, for example, since a light emitting diode and a light receiving transistor are used as a sensor for origin positioning, dust or oil adheres to the sensor. It is also possible that the output of the light-receiving transistor is reduced, and in an extreme case, no output is obtained. In addition, even if a foreign substance such as a pin falls between the spacing space, especially between the carriage and the sensor, it cannot be detected. The mixing of this foreign substance locks the spacing operation of the carriage, and the print head prints a predetermined first character. There arises a problem that the position cannot be set. Moreover, in order to use the light emitting diode and the light receiving transistor as the optical reading sensor,
Other auxiliary parts such as an amplifier are required, which is inconvenient from the viewpoint of cost reduction.

On the other hand, even when the servo motor is used, if foreign matter such as pins is mixed in the spacing space as described above, the foreign matter cannot be detected, and the spacing operation of the carriage is hindered by the foreign matter. All of them present many problems, such as the inability to set the character print position.

<Means for Solving the Problems> The present invention makes the spacing amount of a carriage having a print head correspond to the rotation number of a spacing motor,
The rotation speed of the spacing motor is detected by an encoder via an encode sensor and is output as a position signal, and the position signal is converted into a pulse signal for instructing the moving direction of the carriage by a waveform shaper, and the pulse is output. A signal is output to the servo driver and a counter, the spacing amount is calculated by the μCPU based on the counts by the counter, and the spacing motor is rotationally controlled via the servo driver. 1
A first stopper corresponding to the character printing position is provided, and a second stopper is provided on the opposite side of the path of the end portion and at a constant distance from the first stopper, and the first head by the print head is provided.
Prior to the start of printing characters, in order to move the carriage toward the second stopper, a rotation instruction is given to the spacing motor until there is no change in the spacing amount due to the rotation of the encoder, and the encoder is rotated. When there is no change in the spacing amount due to rotation and the rotation of the encoder exceeds the counter count stored in advance in the memory, the rotation instruction to the spacing motor is stopped and a warning is displayed. Then, when there is no change in the spacing amount, the rotation of the spacing motor is reversed to move the carriage to the first position.
The second motor and the first stopper are moved by a certain distance toward the stopper, and a rotation instruction is given to the spacing motor until the spacing amount does not change due to the rotation of the encoder. When there is no change in the pacing amount, the change in the spacing amount and the constant distance between the stoppers are calculated and compared. If they are substantially the same, the print head is driven to start printing. The present invention relates to a printing start positioning method for a print head in a serial printer, which is characterized by stopping rotation of a single motor and displaying a warning.

<Operation> Prior to starting the printing of the first character, first move the carriage to the second position.
Move toward the stopper. Then, the contact state between the carriage and the second stopper is confirmed. At this time, if foreign matter is mixed between the carriage and the second stopper, the movement of the carriage is stopped, a warning is displayed, and the foreign matter can be removed. If the carriage moves a predetermined distance with respect to the first stopper, the contact state is confirmed.
Further, after the contact state is confirmed, the carriage is moved toward the first stopper by a certain distance. At this time, if foreign matter is mixed in the spacing space formed by the first stopper and the carriage, the carriage is not moved and a warning is displayed, so that the foreign matter can be removed. Then, the contact state between the carriage and the first stopper is confirmed. Moreover, since it is confirmed that the first stopper located at a predetermined constant distance from the second stopper is contacted, the carriage on the carriage with respect to the first character printing position corresponding to the first stopper. The print heads are set up exactly.

Therefore, the entire path of the carriage can be checked at once just before printing is started, and the effect of preventing obstacles from entering immediately before printing is great.

<Example> A printing start positioning method of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic configuration diagram of a positioning mechanism in the present invention. In the illustrated example, reference numeral 1 denotes a carriage on which a print head 2 is mounted. Further, the carriage 1 is driven by a drive belt 5 stretched between pulleys 3 and 4,
A spacing space R along a spacing axis (not shown)
Move left and right. The rotating shaft of the spacing motor M is connected to one of the pulleys 4, and the timing slits 6a, 6b, 6c of the encoder 6 attached to the rotating shaft are detected by the encode sensor 61, and the rotation of the spacing motor M is detected. The corresponding movement amount of the carriage 1 and its change are read. Further, a first stopper 7 is provided, for example, at the left end of the spacing path, and further at the right end opposite to the left end of the spacing path, and at a certain distance A from the first stopper. Two stoppers 8 are provided.

FIG. 2 is a control block diagram of positioning. Ie μ
A drive signal is output from the servo driver 11 according to a control signal from the CPU 10, and the spacing motor M is rotated by this signal. Then, the position signals φA and φB are output to the waveform shaper 12 via the encode sensor 61. In the waveform shaper 12, the position signals φA and φB are output to the carriage 1 respectively.
Is converted into a pulse signal that indicates the left-right movement direction of the. This pulse signal is output to the servo driver 11 again for speed control, and is further output to the counter 13. The counter 13
The CPU counts the amount of movement (spacing amount) of the carriage 1, switches / stops the spacing direction, and counts the counter stored in the memory 14 to perform an abnormality detection process, which will be described later. Next, the print start positioning method of the present invention will be described with reference to the flowcharts of FIGS. 1, 2, and 3.

It is not known where the carriage 1 is located in the spacing space R when the first character starts to be printed, such as when the power is turned on or immediately after the spacing abnormality. Therefore, the μCPU 10 outputs a rotation instruction of the spacing motor M to the servo driver 11 so as to move the carriage 1 toward the second stopper 8. When the spacing motor M rotates according to the above instruction, the drive belt 5 moves the carriage 1 in the direction of the arrow X (S1). The timing slit 6 in the encoder 6 accompanying the rotation of the spacing motor M
The displacements of a, 6b, 6c ... Are detected by the encode sensor 61. Then, as described above, the presence or absence of feedback of the movement change of the carriage 1 is detected in the μCPU 10 (S2). That is, when the carriage 1 is in contact with the second stopper 8, the movement amount of the encoder 6 does not change, and thus the change of the movement amount is not fed back.
In this way, the output of the rotation instruction by the μCPU 10 is repeated until the feedback of the change disappears, in other words, the carriage 1 accurately contacts the second stopper 8 (S3-S).
4-S1-S2-S3).

When the rotation instruction is repeated indefinitely, a foreign substance or the like is present between the carriage 1 and the second stopper 8. In this case, the counter count stored in the memory 14 and the rotation number are When exceeding the contrast, a stop / warning instruction is output, the operation of the spacing motor M is stopped, and a warning display such as an alarm is displayed.

When the contact state between the carriage 1 and the second stopper 8 is confirmed as described above, that is, when the feedback of the change by the encoder 6 disappears, the spacing motor M is set to the first position.
The μCPU 10 outputs a rotation instruction to the servo driver 11 so as to move it toward the stopper 7 direction, that is, in the direction of the arrow Y (S5). Then, similarly to the above, the rotation instruction is repeated until there is no feedback of the change by the encoder 6. At this time, the feedback counter count of the memory 14 that has been cleared in advance by another initialization process is updated (S6-S7-S8-S5-S6-S7). When the carriage 1 performs the spacing operation from the second stopper 8 to the first stopper 7, the spacing distance is a preset constant distance A, and if the distance is strictly measured, this distance A is designed. It is a value to which a tolerance is added.

Therefore, when the feedback of the change by the encoder 6 is eliminated, the total counter count of the feedback amount of the memory 14 is compared with the distance A (including the design tolerance) (S9), and if they are substantially the same, the carriage is compared. 1 indicates that the first head 7 is accurately brought into contact with the first head 7, and the print head 2 is correctly set to the print start position of the first character.

If they do not match, it means that a foreign substance or the like is interposed between the first stopper 7 and the carriage 1. In this case, as described above, the μCPU 10 stops the operation of the spacing motor M and displays a warning. .

When the print head 2 is set to the print start position of the first character as described above, the μCPU 10 outputs a drive signal to the drive circuit of the print head (not shown), and serial printing is started from the first character print position.

<Effects of the Invention> As described above, according to the print start positioning method of the present invention, the carriage is moved toward one stopper prior to the start of printing the first character, and the contact state with this stopper is confirmed. After that, the stopper is brought into contact with another stopper that is at a constant distance from the stopper and that corresponds to the printing position of the first character, so that the print head is set so as to accurately correspond to the printing position of the first character. be able to. Also, to check the contact state of both stoppers by rotating the spacing motor,
Even if a foreign substance such as a pin intervenes in the spacing path, the spacing operation can be immediately stopped, and an alarm or the like is displayed, so that the printing mechanism is not damaged.

In addition, the printing position of the first character can be accurately determined even in a printer in which two or more print media are arranged in one spacing path or a printer in which the spacing range of the carriage extends outside the print media. Further, the presence of foreign matter such as a pin can be promptly detected.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a positioning mechanism according to the present invention, FIG. 2 is a control block diagram thereof, FIG. 3 is a flow chart of the same printing positioning, and FIG. 4 is a schematic configuration diagram of a conventional positioning mechanism. 5, FIG. 5 is the same printing start positioning flowchart, FIG. 6 is a schematic configuration diagram showing the other positioning mechanism, and FIG. 7 is another printing start positioning flowchart. 1 ... Carriage, 2 ... Print head, 6 ... Encoder, 61 ... Encode sensor, 7 ... First stopper, 8 ... Second stopper, 10 ... μCPU, 11 ... Servo driver, 12 …… Waveform shaper, 13 …… Counter, 14 …… Memory, M …… Spacing motor.

Claims (1)

[Claims] 1. A spacing amount of a carriage having a print head and a rotation number of a spacing motor are made to correspond to each other,
The rotation speed of the spacing motor is detected by an encoder via an encode sensor and is output as a position signal, and the position signal is converted into a pulse signal for instructing the moving direction of the carriage by a waveform shaper, and the pulse is output. A signal is output to the servo driver and a counter, the spacing amount is calculated by the μCPU based on the count by the counter, and the spacing motor is rotationally controlled via the servo driver. A first stopper corresponding to the one-character printing position is provided, and a second stopper is provided on the side opposite to the path of the end portion and at a constant distance from the first stopper, and Prior to the start of printing, the carriage is moved toward the second stopper to move the carriage to the encoder. When a rotation instruction is given until the spacing amount due to the rotation of the encoder does not change, the spacing amount due to the rotation of the encoder does not disappear, and the rotation of the encoder exceeds the counter count previously stored in the memory. In addition, the rotation instruction to the spacing motor is stopped and a warning is displayed. Then, when the spacing amount has no change, the rotation of the spacing motor is reversed to move the carriage to the first position. The spacing motor is moved toward the stopper by a predetermined distance formed by the second stopper and the first stopper, and a rotation instruction is given to the spacing motor until the spacing amount is not changed by the rotation of the encoder. When there is no change in the amount, the change in the spacing amount and the constant distance between the stoppers are calculated. If the print heads are substantially matched, the print head is driven to start printing, and if the print heads are not substantially matched, the rotation of the spessing motor is stopped and a warning is displayed. Start positioning method.