CN100421963C - Control method of serial printer and carriage driving motor - Google Patents

Abstract

Since the carriage motor is controlled so that the motor may start with slow-up (t4) by turning on a rush current (R1) during the operation of the paper-feed motor (t3 to t6) and reach the designated constant-speed state when the paper-feed motor stops (t6), the time for rushing and driving the carriage overlaps with the time for driving the paper-feed motor 40. Therefore, the operation of printing can be immediately started (t7) if the paper-feeding operation stops (t6). Accordingly, it is possible to increase the printing-speed without changing the motors while keeping to turn on the same driving current.

Description

Control method of serial printer and carriage driving motor

technical field

The present invention relates to a serial printer that performs printing while using independent stepping motors to perform carriage feeding and recording paper feeding.

Background technique

In a serial printer that performs printing by using separate stepping motors to feed the carriage and the recording paper (Patent Document 1), after feeding the paper in the longitudinal direction, the carriage is moved laterally and simultaneously to print. If you print while feeding the recording paper in the longitudinal direction, the printing speed will increase, but there will be problems such as a deviation in the left end or both ends of a line of characters, resulting in poor print quality. Therefore, conventionally, printing is performed by moving the carriage in the lateral direction after feeding the paper.

〖Patent Document 1〗JP 2001-301275

As described above, in a serial printer, the two-stage operation of feeding the paper and moving the carriage must be continuously performed, and printing speed becomes a problem when printing multiple lines. Recently, with the development of integrated circuit technology, data processing speeds such as microprocessors have been significantly increased, and higher printing speeds are also required in serial printers. By increasing the driving current of the motor and using a high-performance stepping motor, the paper feeding speed and the moving speed of the carriage can be increased, and the printing speed can be increased as a whole, but the product cost and power consumption will increase, and as the carriage The problem that the high-speed movement of the printer increases the operating noise of the printer, etc.

Contents of the invention

The present invention is made in view of the above-mentioned problems in the prior art, and the purpose is to provide a control method of a carriage drive motor and a serial printer using the method, which does not use high-performance motors and does not increase the power consumption And noise, you can increase the printing speed.

A serial printer according to a first aspect of the present invention for achieving the above object includes a paper feed motor for feeding recording paper, and a carriage drive motor for driving a carriage on which a print head is mounted in a direction across the recording paper. A paper feed control section that controls the paper feed motor according to a paper feed command, and a carriage control section that controls the carriage drive motor so that, in the case of printing after paper feed, Move the carriage at a defined constant speed until the end.

In this aspect, control is performed so that the driving operation of the paper feed motor and the initial operation until the carriage driving motor rotates at a predetermined constant speed are repeatedly driven. Thereby, the time necessary for the initial movement of the carriage drive motor is incorporated into the drive time of the paper feed motor, so the printing time can be shortened.

In the serial printer according to another aspect of the present invention, the carriage control unit starts the rush current flow and slow acceleration to the carriage drive motor in advance according to the paper feed end time of the paper feed motor. For example, when the paper feeding amount is different, the paper feeding end timing changes. In this aspect, the drive start timing of the carriage drive motor is adjusted in accordance with the above-mentioned variation in the paper feed amount. Thus, printing can be started at the most appropriate timing even if the width of line feed varies for each line.

In the serial printer according to another aspect of the present invention, the carriage control unit acquires the paper feed information from the paper feed control unit, and adjusts the flow of rush current and slow acceleration according to the paper feed amount of the paper feed motor. start moment. In this aspect, the paper feed information sent to the paper feed control unit is acquired from the main control unit or the paper feed control unit, and the drive start timing of the carriage drive motor is adjusted. The paper feed information may include the paper feed start time which can be obtained from the paper feed control unit.

In the serial printer according to another aspect of the present invention, the carriage control unit calculates the inrush current flow of the carriage drive motor and the start timing of slow acceleration based on the paper feed information. In this form, for example, based on paper feeding information such as the paper feeding amount, the time required for paper feeding is calculated, and the optimum drive start timing of the carriage drive motor is calculated.

In the serial printer according to another aspect of the present invention, the carriage control unit has a control data table that stores control data corresponding to the amount of paper feeding, and the control data is used to calculate the incoming rush current and slow acceleration of the carriage drive motor. start moment. In this form, for example, the time required for paper feeding for each paper feeding amount, the optimum time from the start of paper feeding to the start of driving the carriage drive motor, etc. are stored in the table. Thus, by acquiring the paper feed start time and the paper feed amount, the drive start time of the carriage drive motor can be controlled.

The control method of the carriage motor according to the first aspect of the present invention comprises a paper feed motor for conveying the recording paper, and a carriage drive motor for moving the carriage on which the print head is mounted in a direction crossing the recording paper. In a line printer, a drive control method of a carriage drive motor when printing is performed after paper feeding, the method includes: (a) a process of obtaining the end time of the aforementioned paper feeding; In this process, the inrush current is applied and the acceleration is slowed down so that the carriage moves at a predetermined constant speed at the end of the feeding of the paper.

According to the above-mentioned embodiment of the present invention, during the operation of the paper feed motor, the carriage motor is preliminarily supplied with an inrush current and accelerated slowly, and when the paper feed motor stops, the carriage motor is controlled to reach a predetermined constant value. The speed state, so the time for passing the rush current in the carriage and driving the carriage overlaps with the driving time of the paper feed motor. Therefore, printing can be started directly as soon as paper feeding is stopped. Therefore, the printing speed can be increased by applying the same driving current without installing a high-performance motor. In this way, if the motor used is the same as the driving current, the noise is almost the same as before.

Description of drawings

FIG. 1 is a perspective view showing a schematic configuration of a printer to which the present invention is applicable.

FIG. 2 is a diagram illustrating printing and paper feeding of the printer.

FIG. 3 is a diagram illustrating power transmission of the printer.

FIG. 4 is a diagram illustrating how a platen of the printer is attached.

FIG. 5 is a diagram illustrating power transmission of paper feeding in the printer.

Fig. 6 is a functional block diagram of a printer control unit according to an embodiment of the printer according to the present invention.

Fig. 7 is a time chart illustrating the relationship between the control of the carriage motor and the control of the feed motor according to one embodiment of the present invention.

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. First, a printer to which the method of the present invention can be applied will be described. FIG. 1 is a perspective view showing a schematic configuration of a printer (serial printer) according to this embodiment. FIG. 2 is a diagram illustrating printing and paper feeding of the printer. FIG. 3 is a diagram illustrating the power transmission of the carriage drive and ribbon drive of the printer, and FIG. 4 is a diagram illustrating the installation state of the platen of the printer. FIG. 5 is a diagram illustrating power transmission of paper feeding in the printer.

First, the carriage driving mechanism and its operation will be described with reference to FIGS. 1 to 3 . As shown in FIG. 1 , the printer of the present embodiment is supported by the guide shaft 22 and the guide rail 9 so that it can move back and forth in a direction (direction of arrow C) substantially perpendicular to the feeding direction of recording paper 7 (direction of arrow E). The carriage 21 of the print head 20.

As shown in FIG. 2, the carriage pin 21b protrudes below the carriage 21, and engages with the helical groove 23a provided in the camshaft 23 (feed screw type). A camshaft gear 12, a driven gear, is fixed to one end of a camshaft 23, and meshes with a motor gear 11, a driving gear fixed to a rotary shaft 10a of a carriage drive motor 10 (see FIG. 3).

As shown in Figure 3, once the carriage drive motor 10 is started, the motor gear 11 rotates in the direction of arrow A, then the camshaft gear 12 rotates in the direction of arrow B, and the carriage 21 meshing with the camshaft 23 then rotates in the direction of arrow C (right to left direction) to move (path to go). Similarly, when the motor gear 11 is rotated in the direction opposite to the arrow A, the carriage 21 moves in the direction opposite to the arrow C (the return path).

Furthermore, a shielding plate 21a is provided below the carriage 21, and the presence or absence of the carriage 21 can be detected by detecting the shielding plate 21a with a photodetector 24 provided at the right end from the print head 20 toward the recording paper 7. In this embodiment, the photodetector 24 is a transmissive photodetector in which the light emitting part and the receiving part are arranged oppositely. signal circuit.

The position of the carriage 21 on which the print head 20 is mounted is grasped by counting the number of drive pulses of the carriage drive motor 10 based on a predetermined position (hereinafter referred to as an initial position) set based on the output signal of the photodetector 24 . For example, in the moving process of the return path of the carriage, after the photodetector 24 outputs a high-level signal, the position moved by 10 steps is set as the initial position.

The present invention is not limited to the type of print head, and is applicable to, for example, one of printers using an impact print head, a thermal print head, an inkjet head, or the like. This embodiment shows an example of a dot impact printer. As shown in FIG. 2 , once the print head 20 is energized, the print head needle (not shown in the figure) moves in the direction of the arrow F, and presses the recording paper 7 on the platen 4 with the ink ribbon 50 in between, and prints. Thereafter, while moving the carriage 21 from the initial position in the direction of the arrow C (going path), power is supplied to the print head 20 at a desired timing to perform printing for one pass (for example, one line). Printing is also performed on the returning path, and the carriage 21 returns to the initial position after printing of a predetermined line is completed.

Next, the paper feeding mechanism will be described. As shown in FIG. 1 or FIG. 4 , the carriage drive motor 10 and the paper feed motor 40 are provided at the left and right ends of the paper path of the recording paper 7 and are fixed to side walls 3a, 3b respectively formed of thin metal plates. In this example here, the carriage drive motor 10 and the paper feed motor 40 are stepping motors of the same shape. Moreover, by arranging the motors on the left and right sides, the side walls 3a and 3b can be formed in approximately the same shape. In fact, in a certain product, the shape can be the same, and the shape is the same but part of the hole diameter is different. As shown in FIG. 1, the side walls 3a, 3b support components such as the guide rail 9 and the platen 4, and the above components are fixed on the side walls 3a, 3b by screws.

The outer peripheral parts of the carriage drive motor 10 and the paper feed motor 40, the side part on which the motor gear 41 is mounted, the rear side part on the side opposite to the side part, and the cylindrical protrusions formed protruding toward the rear side part are each made of metal. form. This protruding portion is also a bearing portion of the rotation shaft of the motor. As shown in FIG. 2 , the protrusion 10 b of the carriage drive motor 10 rotatably supports the supported portion 5 a of the paper platen (paper guide) 5 . With the same configuration, the protrusion of the paper feed motor 40 rotatably supports another supported portion (not shown) provided on the end portion on the opposite side of the supported portion 5a. The platen 5 presses the platen 4 in the direction of arrow F by a spring (not shown) caught in the engaging portion 5 b to press the recording paper 7 against the platen 4 .

As shown in FIG. 5, the power of the paper feed motor 40 is transmitted from the paper feed motor gear 41 fixed on the rotation shaft of the paper feed motor 40 to the reduction gear 42 meshed with the paper feed motor gear 11, and fixed on the paper feed motor gear 11. A paper feed gear 44 on one end of the paper feed shaft that meshes with the reduction gear 42 . As shown in FIG. 2 , the paper feed roller 45 is fixed at the approximate center of the paper feed shaft 43 and receives a certain pressure due to the elastic force of the paper platen spring 47 that presses the paper platen roller 46 . The recording paper 7 inserted from the paper insertion port is introduced into the contact portion between the platen roller 46 and the paper feed roller 45 along a predetermined paper path. The recording paper 7 is conveyed in the arrow E direction by the frictional force generated between the feed rollers 45 . By changing the number of driving steps of the stepping motor, that is, the paper feed motor 40 , the paper feed amount can be adjusted arbitrarily. Paper feeding during the printing process is performed after the printing of 1 stroke (either direction) is completed and before the next printing starts. The control of the carriage drive motor 10 and the paper feed motor 40 for carriage movement and paper feed is the main content of the present invention and will be described later.

Next, the take-up mechanism of the ink ribbon will be described. An ink ribbon cassette (not shown in the figure) is arranged on the guide rail 9 . As shown in FIG. 3 , the power to feed the ink ribbon 50 is obtained through the sun gear 12 a provided on the cam gear 12 . A switching lever 51 that swings between G to H centered on the camshaft 23 is pivotally supported on the camshaft gear 12, and furthermore, a planetary gear, that is, an ink ribbon transmission gear 52 is pivotally supported on a shaft provided at the front end of the switching lever 51. , while meshing with the sun gear 12a. Only when the camshaft 23 rotates in the direction of the arrow B, and with this rotation, the switching lever 51 is stabilized at the H position, the ink ribbon transmission gear 52 meshes with the spur gear 53a of the ink ribbon drive gear 53 to make the ink ribbon drive gear 53a move in the direction indicated by the arrow. Rotate in the I direction. Thereafter, the ink ribbon take-up gear 54 with the worm wheel 54 a is rotated in the arrow J direction by the worm 53 b provided at the front end of the ink ribbon drive gear 53 to feed the ink ribbon 50 . On the other hand, when the camshaft 23 rotates in the direction opposite to the arrow B, since the switching lever 51 is stabilized at the G position, the engagement between the ink ribbon delivery gear 52 and the ink ribbon drive gear 53 is released, and the ink ribbon take-up gear 54 is released. The power transmission is off, so the ink ribbon 50 is not fed. That is, only when the carriage 21 moves in the arrow C direction, the ink ribbon 50 is wound up, and when the carriage 21 moves in the direction opposite to the arrow C, the ink ribbon is not wound up.

(Relationship between carriage motor control and paper feed motor control)

As described above, printing is performed on the recording paper 7 by mutually driving the paper feed motor 40 and the carriage drive motor 10 . Next, drive control of the paper feed motor and the carriage motor will be described. FIG. 6 is a functional block diagram of a printer control unit 60 according to an embodiment of the printer of the present invention. The printer control unit 60 includes an interface 61 for transferring control commands from the host device to other data communications, a main control unit 62 for controlling the printer as a whole, a printing control unit 63 for controlling printing, a carriage control unit 64 for controlling the movement of the carriage, A paper feeding control section 65 that controls paper feeding.

The carriage control unit 64 further includes a drive control unit 66 for controlling the drive of the carriage drive motor 10, a paper feed information acquisition unit 67 for acquiring paper feed information, and a carriage drive motor for storing information corresponding to the acquired paper feed information. The control data table 68 of the driving moment data. In addition, the printer control unit 60 can be constituted by CPU, ROM, RAM, control program, and control data. Usually, there are logic control circuits, power supply circuits, driving mechanisms, conveying mechanisms, etc. between the printer control unit 60 and the print head 21, the carriage drive motor 10, and the paper feed motor 40. Shows.

The printer control unit 60 executes printing and paper feeding operations according to control commands issued by the host device. Control commands issued by the host device are input to the main control unit 62 from the interface 61 through a receiving buffer (not shown in the figure). The main control unit 62 sends necessary control data to the print control unit 63 , the carriage control unit, and the paper feed control unit 65 according to a print command, a paper feed command, and the like.

Paper feeding is performed by the paper feeding motor 40 as previously described. The print position (position of print line) in the longitudinal direction on the recording paper 7 is controlled by controlling paper feed. The paper feeding control unit 65 controls the operation of the paper feeding motor 40 to feed the paper by an amount instructed by a control command from the host device.

The print head 20 prints the print data received from the host device on the recording paper 7 . The print control section 63 converts the print data into bitmap data (dot data) of one processing part (e.g. equivalent to one bill part) or one row, and expands it in a print buffer (not shown in the figure), so that the expanded The dot data of each line is kept synchronous with the paper feeding of each line, and at the same time, the printing head 20 is controlled to print line by line. When printing 1 line, the paper feed stops. One line is sequentially printed while moving the carriage 21 on which the print head 20 is mounted in the lateral direction. The print head 20 synchronizes the moving position of the printing carriage with the printing content in one line, and simultaneously prints corresponding characters and the like.

Paper feeding is stopped during printing of one line, and paper feeding of the next line is started after printing of one line is completed. Printing of the next line is performed from the stop of paper feeding. In the present invention, synchronously with the end of the paper feeding controlled by the paper feeding control unit 65 (considering various conditions such as physical operation time, more or less deviation can be set) from before the paper feeding motor 40 stops. The carriage drive motor 10 is started to be driven so that the moving speed of the carriage 21 becomes a predetermined speed. The paper feeding information acquisition unit 67 acquires paper feeding information for predicting the end time of paper feeding. Since the end of paper feeding is determined by the paper feeding amount sent from the main controller 62, it is only necessary to be configured to acquire the paper feeding information sent from the main controller to the paper feeding control unit. The control data table is a table that stores data on the timing of starting to drive the carriage drive motor according to the paper feed amount.

It is preferable to use a stepping motor as the carriage driving motor 10 and the paper feeding motor 40 . The stepper motor receives an inrush current when it is driving and when it stops, and accelerates to a specified constant speed through slow acceleration (slow up). After the carriage drive motor 10 reaches a predetermined constant speed state, printing is performed with the print head 20 . Also, printing is performed while paper feeding of the recording paper 7 is stopped. Therefore, when paper feeding and printing are continuously performed alternately, until the end of paper feeding (recording paper 7 stops), once the moving speed of the carriage reaches a predetermined constant speed state, there is no need to wait for the energization time of the rush current and slow acceleration. Printing can be started immediately, enabling high-speed printing.

The carriage control section 64 acquires the paper feeding amount and the paper feeding start time performed next to the paper feeding information. Also, the time necessary for paper feeding can be obtained from the control data table. Furthermore, the time required to accelerate the moving speed of the carriage 21 to a predetermined constant speed is known in advance (it can be stored in a control table or the like). The carriage control unit 64 calculates the standby time by subtracting the time required to accelerate the carriage from the time required for paper feeding, and the time required for the carriage drive motor 10 to pass after the standby time elapses from the paper feeding start time. Inrush current is applied and acceleration begins slowly. Thereby, the carriage drive motor can be controlled so that the moving speed of the carriage reaches a constant speed at the end of paper feeding.

(Drive timing of the carriage motor)

FIG. 7 is a time chart comparing the timing of driving the carriage motor according to one embodiment of the present invention and the timing of controlling the carriage motor according to the prior art.

Fig. 7 shows that paper feeding is stopped (maintained) at first, and the carriage is moved from left to right while stopping after one line of printing is completed, and after feeding one line of paper, the carriage is moved from right to left Move in the direction, print at the same time, and then continue to print from left to right after feeding one line of paper. In addition, the timing chart of the conventional carriage drive control shows a case where the carriage moves from left to right, stops, and then starts to move from right to left.

Hereinafter, "inrush current" refers to a current applied to fix the drive phase when the motor stops or starts driving, and "maintenance" refers to a state of maintaining current energization in the same phase as the inrush current. Furthermore, "R1" indicates that the rush current is supplied to the carriage driving motor, "R2" indicates that the rush current is supplied to the paper feed motor 40, and "H1" indicates that the holding current is supplied to the carriage driving motor.

From the state where the carriage 21 stops at the initial position, the carriage drive motor 10 is driven, and the carriage 21 starts to move rightward. Once the slow acceleration is over and the defined constant speed state (t1) is reached, printing can begin. In addition, setting the period s1 before the printing start time t1 is for correctly printing complex characters such as Chinese characters, and for ensuring a stable operation of the carriage.

Printing is performed based on the print data expanded in the print buffer. Once printing of one line is completed (t2), the carriage drive motor 10 is slowly decelerated (slow down). FIG. 7 shows an example in which the constant speed is slightly extended and then slowly decelerated in consideration of the execution delay time of several dots of the printing operation after the drive signal is sent to the print head.

The driving of the paper feed motor 40 is started after the printing is completed. In order to start the slow acceleration of the feed motor 40 as early as possible, the inrush current ( R2 ) is applied from before the printing end time, and the slow acceleration is started after the printing is finished ( t3 ). As a result, the feed motor 40 is driven to feed one line of paper.

During this period, the carriage drive motor 10 ends the slow deceleration, enters the maintenance (H1) state after passing through the shock current (R1), and passes through the shock current (R1), and then starts to slowly accelerate, so that printing can be performed immediately when the paper feeding is completed . The next printing is to print the next line while moving the carriage 21 in the opposite direction (from right to left). Since the time required for the paper feed motor 40 to feed one line of paper is known in advance, if the paper feed amount and paper feed start time are known, the inrush current (R1) and slow acceleration of the carriage drive motor 10 can be calculated. time (t4). In this way, by accelerating slowly in advance, the carriage reaches a predetermined constant speed (t5) at the time (t6) when paper feeding ends. Therefore, printing can be started immediately after the paper feeding is completed and the recording paper is stopped (t7).

In contrast, until the carriage drive motor 10 slowly decelerates and the inrush current ( R1 ) is applied, the drive control of the carriage motor in the prior art is the same as that of the present invention. However, until the paper feed motor 40 stops and the recording paper stops, the carriage drive motor 10 is kept in the maintenance state (H1), and the inrush current (R1) is supplied and slowly accelerated from the stop of the recording paper. Therefore, the moment (t5) at which the carriage 21 reaches a constant speed is much later than in the present invention. This difference allows the present invention to increase printing speed. Since the present invention does not particularly increase the speed of the carriage, the noise produced by driving the carriage and the braking noise at stop are the same as those of the prior art.

In the present invention, the paper can be printed immediately after feeding, and the next line is printed sequentially from right to left. After the printable period ends (t8), the carriage drive motor 10 starts to slowly decelerate. Almost at the same time, a surge current (R2) is applied to the paper feed motor 40, and a slow acceleration starts (t9). When the carriage motor 10 stops, a surge current (R1) is supplied. However, when the left carriage reverses, the hold time is not set. This is because, in the present embodiment, the ink ribbon is driven only when the carriage is driven in the C direction, so that the slow acceleration period of the carriage can be shortened. That is, in this embodiment, the ink ribbon is driven by the power of the carriage motor, and when driving in the direction opposite to the C direction, the power for winding the ink ribbon can be ignored, so the number of steps for slow acceleration can be reduced. If the inrush current is applied→maintained→inrush current is applied, the paper feeding time will be lengthened, so the hold state is omitted, and the inrush current at driving and the inrush current at stop are combined into one inrush current.

In addition, in Fig. 7, between t10 and t11, the number of steps for the slow acceleration of the carriage motor is omitted, and in order to make the total number of steps from right→left and left→right the same, a period s2 is set. After the end of printing (t8) when the carriage moves from right to left.

Thereafter, the same control is repeated, and the printing of the number of lines designated by the host device is executed.

As mentioned above, when the present invention continuously prints after the paper is fed, the carriage reaches a predetermined constant speed when the paper feed motor stops by controlling the inrush current and the slow acceleration timing of the carriage drive motor. Thus, the printing time can be shortened.

One embodiment of the present invention has been described above with reference to the accompanying drawings, but the present invention is not limited to the forms shown in the above-mentioned embodiments, but includes descriptions based on technical solutions and well-known technologies, and those skilled in the art can make changes, scope of application. By using a high-performance motor, the present invention can further increase the printing speed.

Claims (6)

1. A serial printer comprising a paper feed motor for conveying recording paper, a carriage drive motor for driving a carriage equipped with a printing head in a direction across the recording paper, characterized in that the printer is equipped with a The paper feed command controls the paper feed control section of the paper feed motor, and the carriage control section that controls the carriage drive motor so that when printing is performed after the paper feed, Moves the carriage at a specified constant speed until paper feeding ends. 2. The serial printer according to claim 1, wherein the carriage control unit starts in advance to pass inrush current to the carriage drive motor and slowly accelerate. 3. The serial printer according to claim 2, wherein the carriage control unit acquires the paper feed information of the paper feed control unit, and correspondingly corresponds to the paper feed amount of the paper feed motor Adjust the start time of the aforementioned inrush current and slow acceleration. 4. The serial printer according to claim 3, wherein the carriage control unit calculates the start time of the inrush current and the slow acceleration of the carriage driving motor based on the paper feeding information. 5. The serial printer according to claim 4, wherein said carriage control unit has a control data table storing control data corresponding to said paper feed amount, said control data being used to calculate said carriage drive Inrush current of the motor and start time of slow acceleration. 6. A drive control method for a carriage motor, comprising a series of paper feed motors for conveying recording paper, and carriage drive motors for moving a carriage on which a print head is mounted in a direction crossing the recording paper. In a line printer, a method for driving and controlling a carriage driving motor when printing is performed after paper is fed, is characterized in that the method includes: (a) a process of acquiring the end time of the aforementioned paper feeding; and (b) A step of starting the rush current to the carriage drive motor and gradually accelerating it so that the carriage moves at a predetermined constant speed at the end of the feeding of the paper.

Images