JPH08207372A - Shuttle printer - Google Patents

Abstract

PURPOSE: To obtain high printing quality by a method wherein the precise paper feeding amount of a medium to be recorded is realized at the printing action of a shuttle printer. CONSTITUTION: A plurality of printing pins are arranged in a row normal to the transferring direction of a medium to be recorded so as to perform printing action by sinusoidally reciprocatingly rocking all the printing pins to the direction of the row of the pins. At the same time, when the medium to be recorded is fed by the amount corresponding to one dot at the rocking ends of the pins with a paper feeding motor of four phase step motor, two steps having tire durations of t2 and t3 are driven to a normal direction by two phase excitation and then one step having the duration of t4 is driven to reverse direction by two phase excitation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention arranges a plurality of unit printing mechanisms for moving printing pins back and forth, and these printing pins are arranged in a row in a direction intersecting the feeding direction of a recording medium. In addition, the present invention relates to a shuttle printer in which printing is performed while reciprocally swinging these print pins in a direction intersecting the feeding direction of a recording medium, and more specifically, paper feed control for this kind of shuttle printer. It is about.

[0002]

2. Description of the Related Art In recent years, a step motor is often used as a drive motor for a paper feeding mechanism in a printer. Then, as a method of driving (exciting) a step motor having multi-phase (2, 3, 4, etc.) windings, two-phase driving is performed while simultaneously exciting two phases (windings) of the multi-phase windings. There are an excitation drive method and a 1-2 phase excitation drive method in which the excitation drive of one phase of the multi-phase winding and the two-phase excitation drive are alternately repeated, and in the case of the two-phase excitation drive, Has a large output (rotation) torque because it constantly excites two windings (phases) to rotate the motor rotor. On the other hand, in the 1-2 phase excitation drive, the rotational torque becomes smaller by the amount of power consumption per cycle that is smaller than that in the two phase excitation, but the resolution, that is, the so-called stepper motor is rotated every time a pulse is applied Since the angle (step angle) is 1/2 in 1-2 phase excitation as compared with 2-phase excitation, there is an advantage that smooth rotation can be obtained.

Therefore, the applicant of the present invention firstly put in practice Kaihei 5-418.
As disclosed in Japanese Laid-Open Patent Publication No. 08-2008, a print head for driving a dot matrix is mounted on a carriage, and one line is printed while moving the carriage in a direction orthogonal to the paper feeding direction of a recording medium (paper). If the carriage moves to the end portion in the paper width direction, the paper feed step is driven in the dot type serial printer that feeds the paper in the paper feed direction (line direction) by the line feed and then prints. When executed by a motor, a high torque is generated during a line feed operation, a two-phase excitation drive that enables high-speed paper feeding, and a 1-2 phase excitation drive that can obtain smooth rotation during a page break operation are performed. It was proposed to switch the driving form.

On the other hand, as an example of a shuttle printer, as described in Japanese Patent Publication No. 57-52913,
A plurality of unit printing mechanisms for moving the printing pins forward and backward are arranged in a row, and these printing pins are arranged in a row in a direction intersecting the feeding direction of the recording medium, and the tip portions of these printing pins are arranged. It is disclosed that only the appropriate one of the plurality of unit printing mechanisms is selectively driven to print while only reciprocatingly swinging only the unit in a direction intersecting the feeding direction of the recording medium.

In this case, after a row of dots is printed while the print pin is moving in one direction, when it comes to the swing end of the print pin, the paper is advanced by one dot in the row direction in the row direction. , And the next line of dots is printed by reversing the movement. For example, in the case of printing letters, numbers, katakana (hereinafter referred to as ANK letters) and barcodes, one character is printed in the paper feed direction by 8
If you use dots to print the one character,
It is necessary to swing the print pin so that it reciprocates 4 times.

Therefore, in this kind of shuttle printer, in addition to the line feed operation and the paper feed operation accompanying the page break operation, when the character for one line is printed, the recording medium (paper) is the same as described above. As described above, it is necessary to feed the paper finely at a dot interval in the row direction and quickly.

[0007]

However, since it is necessary to frequently feed the paper in a very short time, such as during printing operation in the shuttle printer, 1
If the paper feed during the printing operation for one line is executed by the 1-2 phase excitation as described above, the paper feed speed is slow and high-speed printing cannot be performed.

On the other hand, when the two-phase excitation is performed, the output (rotation) torque is too large, and therefore the rotational inertia force of the rotor of the step motor causes excessive movement from a predetermined stop position (stable point). Becomes 1 in the row direction
The recording medium moves more than the paper feed for dots,
There is a problem that the dot spacing in the row direction is disturbed and it is difficult to realize high quality printing.

Further, when drawing a graphic such as a graph, a figure, or a painting, it is necessary to feed the paper more finely than during the printing operation of the ANK character or the bar code so as to obtain high quality. Further, during the line feed operation, the paper feed mechanism must execute an operation cycle of acceleration, deceleration, and stop to accurately stop the paper at a predetermined position. Therefore, a high torque is required for the step motor.

Therefore, the present invention solves the problems in the prior art by making it possible to switch the phase excitation drive of the operation of the step motor according to the type of printing and the work associated with the printing operation. An object of the present invention is to provide a shuttle printer which can obtain printing quality and can perform high-speed printing.

[0011]

In order to achieve the above object, a shuttle printer according to a first aspect of the present invention has a plurality of unit printing mechanisms for advancing and retracting the printing pins arranged in a row, and A shuttle printer configured to drive printing while reciprocally swinging at a constant cycle in a direction intersecting a feeding direction of a recording medium, wherein a step motor is used as a driving unit of a paper feeding mechanism of the recording medium. , And during the printing operation, following the two-step forward excitation,
The control is performed so as to execute the anti-phase excitation in one step.

According to a second aspect of the present invention, in the shuttle printer according to the first aspect, during the paper feeding operation during non-printing, control is performed so as not to perform the reverse phase excitation of the step motor. It is a thing. According to a third aspect of the invention, in the shuttle printer according to the first aspect, the minimum unit of the paper feed amount is realized by ½ rotation of the step angle of the step motor. 2 phase excitation drive control,
The selection means for controlling the two-phase excitation drive is provided.

[0013]

[Embodiments] Next, embodiments embodying the present invention will be described. FIG. 1 is a side sectional view of a shuttle printer 1, and FIG. 3 is a perspective view of a print head 2, respectively. The shuttle printer 1 of the present invention is arranged between a cover upper body 4 and a cover lower body 5 arranged on an upper portion of a frame 3. The printing is performed on the lower surface of the recording medium 7 such as a sheet of paper which is transported in the direction of arrow A in FIG. 1 by the driving roller 6a and the pressing roller 6b in the sheet feeding mechanism 6 provided in the sheet path. A print head 2 which will be described later in confrontation with a substantially trapezoidal platen 8 fixed to the lower surface of the cover upper body 4.
Are arranged, and the print pins 13 of the unit print mechanism 12 in the print head 2 are arranged in a line in a direction orthogonal to the transfer direction of the recording medium 7. The print pins 13 are arranged in the arrangement direction at a predetermined amplitude. Platen 8 swinging left and right along
The recording medium 7 is projected toward the lower surface of the recording medium to print on the surface of the recording medium 7 via the ink ribbon, and the recording medium 7 is cut into a predetermined length by the rotary type cutting device 9, and then the rubber is cut. The discharge rollers 10 are formed so as to be ejected to the outside of the machine by a plurality of radially projecting protrusions.

The basic structure of the print head 2 of this embodiment is as follows.
As shown in FIGS. 2 to 6, a base body 11 made of a metal and having an upward U-shaped cross section is disposed so as to face each other in the base body 11 and is orthogonal to the feeding direction of the print medium 7. Two
A plurality of unit printing mechanisms 12 arranged in rows, a swingable support member 14 for guiding and supporting a midway portion of the print pin 13 in each unit printing mechanism 12, and this support member 14
And a swing interlocking mechanism 15 for swinging back and forth in a direction orthogonal to the feeding direction of the recording medium 7.

The base 11 which is long in the direction orthogonal to the feeding direction of the recording medium 7 is made of metal such as aluminum alloy, the support member 14 is made of synthetic resin such as PBT, and the support member 14 will be described later. As described above, the cover body 16 is integrally formed with a screw so as to cover the upper surface of the base body 11. A plurality (28 in the embodiment) of the unit printing mechanisms 12 are provided on the vertical side plate 11 which is relatively opposed to the base body 11.
a, 11a are arranged alternately (in a zigzag shape) along the longitudinal direction of the recording medium 7 in a direction orthogonal to the feeding direction of the recording medium 7, and the main frame 21a of each unit printing mechanism 12 is provided on the inner surface of each vertical side plate 11a. The back surface is brought into contact with and fixed with screws 17 or the like. Therefore, 14 unit printing mechanisms 12 are arranged for each vertical side plate 11a, and a plurality of printing pins 13 are arranged in a line in plan view (see FIG. 3).

As shown in FIG. 6, each unit printing mechanism 12 has a vertically elongated piezoelectric element 18 in which a plurality of rectangular piezoelectric ceramics each having a thickness of about 100 microns are laminated, and a tip of the piezoelectric element 18. A drive mechanism 19 mounted on the upper end of the piezoelectric element 18 for enlarging the expansion / contraction motion of the piezoelectric element 18 and transmitting the expanded / contracted movement to the print pin 7, and a generally upward upward side view supporting the drive mechanism 19 and the piezoelectric element 18. The U-shaped support frame 21 is made of a material having a small linear expansion coefficient, such as a U-shaped iron or nickel alloy (Invar alloy).

When charged by applying a voltage, the piezoelectric element 1
Numeral 8 extends in the laminating direction (longitudinal direction) and contracts when discharged. Since the piezoelectric element 18 shrinks as the temperature rises, the temperature compensator 20 having a positive temperature expansion characteristic for correcting the temperature is inserted between the lower end of the support frame 21 and the rear end of the piezoelectric element 18, Stick with an adhesive.

The drive mechanism 19 has a substantially triangular arm 22 in side view formed by brazing a base of a print pin 13 having an appropriate length (50 mm in the embodiment) to the tip, and the support frame 21.
Of the main strut portion 21a in the longitudinal direction rearward in parallel with the first plate spring and the second plate spring, and a rigid connecting portion that connects the tip ends of the two plate springs to each other. The spring body 23 and the four-node link member 24 are fitted and fixed to the base end of the arm 22 by brazing or the like. The base end of the first leaf spring is connected to the main strut 2
While being brazed and fixed to the side surface of 1a, the base end portion of the second leaf spring is also fixed to the movable element 25 that comes into contact with the front end surface of the piezoelectric element 18 in a pressed state by brazing or the like.

The four-node link mechanism member 24 made of an elastic material such as a spring plate is provided on the other side of the mover 25 and the support frame 21.
Of the four-node link mechanism member 24 is provided so as to straddle the sub strut portion 21b in FIG. Then, the left and right wide side plates are fixed to the front and back side surfaces of the auxiliary column portion 21b and the front and back side surfaces of the mover 25 by spot welding (also possible by brazing), and when the piezoelectric element 18 expands and contracts by voltage application, it is a four-section link. The left and right wide side plate portions of the mechanism member 24 are elastically deformed into a parallelogram shape in a side view and positionally fixed.
The movable element 25 is configured to be movable in parallel along the longitudinal direction of b.

Then, at a predetermined timing, each piezoelectric element 1
Control device 7 of shuttle printer 1 so that 8 operates.
In order to transmit the drive voltage signal from 0, in order to electrically connect with the printed board 26 on the outer surface of the bottom plate portion of the base body 11,
A pair of lead portions 27, 27 are provided. With this configuration,
At the time of printing operation, when the piezoelectric element 18 is extended along the longitudinal direction by applying a voltage, the spring body is set so that the rotation center is a substantially midway portion in the longitudinal direction of the first leaf spring fixed to the main support column 21a. 23 is oscillated and displaced, and the displacement amount is enlarged by the arm 22 via the connecting portion, and the print pin 13 is advanced toward the lower surface of the platen 8 to mount the ink ribbon on the cover upper body 4. The surface of the recording medium 7 is stamped via the ink ribbon fed from the cartridge 28.

Next, the structures of the support member 14 and the swing interlocking mechanism 15 will be described with reference to FIGS.
The support member 14 is a cover body 1 that covers the upper surface of the base body 11.
6, a pair of flexible struts 30 projecting upward from
And a main guide piece 31 that integrally connects the upper ends of the pair of columns 30 and 30 along the longitudinal direction of the platen 8, and is provided at the central portion of the cover body 16 that covers the upper surface of the base body 11. Is provided with a slot 32 through which the print pins 13 projecting in a row are inserted, and a pair of flexible columns 30, 3 is provided from both ends of the cover body 16 (both longitudinal ends of the slot 32).
0 is projected integrally upward.

Further, the main guide piece 31 and the plurality of flexible auxiliary guide pieces 33 for connecting the upper and lower midway portions of the pair of columns 30 and 30 to each other have a fixed interval (2.8 mm in the embodiment). ) Are provided with guide holes (not shown) for slidably guiding and supporting the print pins 13 arranged in a line. It should be noted that both ends of each auxiliary guide piece 33 in the longitudinal direction are rotatably connected to the support columns 30 via connecting pins 34, respectively.

Next, the swing interlocking mechanism 15 will be described with reference to FIGS.
This will be described with reference to FIGS. 5 and 7. The main guide piece 3
A connection block 37 including a horizontal pin 36 that horizontally projects toward the upstream side in the transport direction of the recording medium 7 is fixed to the support block 35 at the central portion of the side surface 1 in the longitudinal direction with screws 38. Then, the base end of the crank arm 40 pivotally connected to the horizontal pin 36, which is a swing connection portion between the support member 14 and the swing interlocking mechanism 15, is rotatable via a bearing 41 in the frame 3. Eccentric rotor 3 supported by a shaft
9 is rotatably mounted and has an eccentric rotor 3 with one swing amplitude e.
Reference numeral 9 is configured to be rotationally driven in a fixed direction through a swing motor 42 that rotates at a fixed speed in a fixed direction and a speed increasing transmission gear mechanism 43.

A linear encoder as a sensor means for controlling the print timing is provided near the support member 14. That is, as shown in FIGS. 1 to 5, on one side of the main guide piece 31, a sensor piece 44 made of a synthetic resin thin plate such as polyethylene terephthalate is arranged along the longitudinal direction, and the sensor piece 44 is arranged. Both ends of are attached to brackets 45 which are detachably attached to the side surfaces of the pair of columns 30 and 30. The sensor piece 44 is provided with a forward slit portion 46a made up of eight slits 46 for printing timing and a backward movement slit portion 46b made up of the same eight slits 46. Each slit portion is formed. Light transmission type detectors 47a and 47b such as photo interrupters are arranged so as to sandwich the sensor piece 44 from above and below with respect to 46a and 46b. In the embodiment, the support member 14 and thus the print pin 13 are sine-wave oscillated as will be described later, and the intervals P1 of the dots 13a of the print pin 13 are made substantially equal. Therefore, the intervals of the slits 46 are unequal. The intervals are set.

That is, in the embodiment, the support member 14 and thus the print pin 13 are sine-wave oscillated as will be described later, and as shown in FIG.
Intervals P1 (for example, 1/72 inch dot intervals) are made substantially equal, the intervals Δf1 to Δf7 of the slits 46 corresponding to the forward movement and the slits 4 corresponding to the backward movement are provided.
The intervals Δr1 to Δr7 of 6 are unequal intervals.

FIG. 9 shows a functional block diagram of the control device of the present invention. The printer control device 70 including a microcomputer in the shuttle printer 1 stores a central processing unit (CPU) and a control program (not shown). It comprises a read-only memory (ROM), a readable / writable memory (RAM) for storing various data, an input / output interface, and the like. The input interface includes a rotary phase angle detector 60 in the cutting device 9 and a swing of the print head 2. Optical transmission type detectors 47a and 47b for detecting the movement and print timing are connected to a paper feed sensor 61 for detecting that the front end of the recording medium in the conveyance direction has reached the position of the drive roller 6a in the paper feed mechanism 6. Then, the respective detection signals are input.

The output interface of the printer controller 70 includes a cutting device controller 73 for operating the drive circuit 72 of the drive motor 56 and the swinging motor 4 for the print head 2.
A print control unit 76 for a rocking drive circuit 74 that operates 2 and a print drive circuit 75 that operates the piezoelectric element 18,
A paper feed control unit 78 for a paper feed drive circuit 77 for operating the paper feed motor 6c composed of a four-phase step motor is connected, and each drive circuit is operated according to a printing operation.

Further, the paper feed motor 6c is constructed so as to realize the minimum unit of the paper feed amount by ½ rotation (1 / 2θo) of the step angle of the step motor. Excitation drive control and 1-2 phase excitation drive control selection means are provided. As described below,
When printing letters, numbers, katakana characters, and barcodes,
The above-mentioned two-phase excitation drive control is executed for the line feed operation and the page break operation.
Since the -2 phase excitation drive control is performed, therefore, the command sent to the printer control device 70 by the host computer 71 is preferable as the selection means. Also,
A print switch of a panel switch (not shown) provided on the shuttle printer 1, a line feed switch, a page break switch, or a graphic switch may be used as the selection means.

Next, the printing operation will be described. When the power switch of the shuttle printer 1 is turned on, the swinging motor 42 is activated and the eccentric rotor 39 rotates in a fixed direction via the speed increasing transmission gear mechanism 43. When a print command is issued after the swing motor 42 reaches a constant rotation speed, the recording medium 7 is transported by the paper feeding mechanism 6 in the direction of arrow A in FIG.

When the eccentric rotor 39 rotates at a constant speed, the main guide piece 31, which is the supporting member 14 via the crank arm 39 and the lateral pin 36, is centered on the bases of the pair of columns 30, 30, as shown in FIG. 3 and C and D of FIG. Therefore, the tip end side of each print pin 13 receives lateral pressure on the side surface or side edge of the guide hole 31a in the main guide piece 31, and each print pin 13 bends left or right around its base end, As shown by the solid line in FIG. 11, the tip of the print pin 13 oscillates like a sine wave 50 with a single amplitude amount a (see FIG. 10). The broken line in FIG. 11 is the velocity curve of the printing pin 13, and the cosine wave 5
Becomes 1.

The print start timing is shown in FIG.
As shown in, for example, the swinging U-turn section Tu in which the main guide piece 31 is reversed from the swinging end in the C direction and moves in the D direction.
When the main guide piece 31 makes a U-turn at the right swing end or the left swing end, a predetermined number of dots are printed in the printing section Tp sandwiched by the swing U-turn sections Tu on both left and right sides.
In the print section Tp, the amount of one-sided amplitude is Pa, and the absolute value of the swing speed of the print pin 13 is large, but the fluctuation of the speed is small. On the other hand, the swing U-turn section T
At u, the absolute value of the swing speed of the print pin 13 is small,
Since the fluctuation of the speed is large, this swing U-turn section T
Perform a line feed operation between u.

That is, in the printing section Tp, the dot pattern data developed into the dot pattern corresponding to the character of the input print data and the light transmission type detector 47 for the forward slit 46a shown in FIG.
When a pulse voltage is applied to the piezoelectric element 18 in the predetermined unit printing mechanism 12 based on the voltage application timing to the piezoelectric element 18 detected by the light transmission type detector 47b for the a or the return slit portion 46b, the printing pin 13 The dots can be momentarily projected in the direction of the platen 8 and dot-printed on the surface of the recording medium 7 via the ink ribbon.

In this way, the print pins 13 are C and D.
Dots are printed one after another at a predetermined printing timing while moving in the direction. When the main guide piece 31 reaches the U-turn section Tu at the swing end, the paper feed mechanism 6 is intermittently operated to
After the recording medium 7 is moved in the row direction by the amount of dots, dot printing is performed in the same manner as described above. In this case, when printing letters, numbers, katakana (the above character types are called ANK) and bar codes, in order to move the recording medium 7 by one dot in the row direction, the step motor in the paper feeding mechanism 6 is used. When the print pin 13 comes to the U-turn section Tu at the swinging end while the paper feed motor 6c is excited for two phases as shown in FIG.
Only perform reverse excitation. That is, in the case of a 4-phase step motor, 2 out of the 4 phases (φ1, φ2, φ3, φ4)
The phases are excited at the same time, and the phases are temporally shifted one by one and excited. For example, as shown in FIG. 12B, at the print timing in the forward direction of the print pin 13 (see FIG.
2 (a)), the two phases (φ1, φ2) are excited during the time t1 for printing 8 dots on the print pin 13, and then the phases (φ2, φ3) are excited for t2 hours, and then t3. Two-phase excitation in the forward direction is performed for the time only (φ3, φ4), but after that, the opposite phase excitation is performed for the time (t4) to excite the (φ2, φ3) phase (the phase is opposite when viewed from the point of time t3) After printing, at the print timing in the backward direction (Fig. 1
2 (a)), the two-phase excitation in the forward direction returns to (φ3, φ4). By doing this, FIG.
As shown in FIG.
With u, the recording medium 7 can be fed in the row direction at a step angle of 1 dot (2θo). That is, when the paper feed is executed in the two-phase forward excitation step, the inertia of the rotor of the step motor is too large, and the paper may be fed beyond the one dot. In order to eliminate this inconvenience, in this step motor, two steps of forward two-phase excitation drive are performed, and then one step of opposite-phase excitation drive is performed. The braking force in the opposite direction is applied to the rotor of the step motor, and the recording medium 7 is
The paper can be accurately fed in the row direction by the dot amount, for example, (1/72) inch.

When the printing operation for one line is completed and a new line is started, a blank space for a plurality of unprinted lines is opened, or a page break operation is performed, the four phases (φ
1, φ2, φ3, φ4), two phases are excited at the same time, and they are excited by shifting one phase by time. For example, as shown in FIG. 12D, the order of excitation is (φ1, φ
2) → (φ2, φ3) → (φ3, φ4) → (φ4, φ
Only the two-phase excitation drive in the forward direction is executed as in 1).

As a result, the step motor can rotate at a high speed with a high torque, and the recording medium 7 can be fed to quickly perform a line feed or page break. On the other hand, when drawing a graphic such as a graph, a figure, or a painting, it is necessary to feed the paper more finely than during the printing operation of the ANK character or the barcode so as to obtain a high quality image. In this case, as shown in FIGS. 13 (a) and 13 (b),
Excitation is performed at (φ1, φ2) for one reciprocation (t6) of the swinging of the print pin 13 in the lateral direction (column direction) of the recording medium 7, and then the recording medium 7 for one dot (the above When the paper is fed in the row direction by half the step angle in the case of ANK characters, for example, (1/144) inch, the section (t7) is driven by the two-phase excitation in the forward direction of (φ2, φ3), and then the section (t8). ) Executes the reverse-phase excitation drive of (φ1, φ2).
Then, the excitation of the next reciprocating swing of the print pin 13 is executed at (φ2, φ3). As a result, the paper feeding of the recording medium can be performed finely and smoothly.

At this time, the printing position F by the printing pin 13 when moving the printing pin 13 in the forward direction and the printing position R by the printing pin 13 when moving the printing pin 13 in the backward direction. Is printed so as to be displaced by an appropriate distance with respect to the lateral direction (column direction) of the recording medium 7. For example, as shown in FIG. 13C, when the printing position in the backward direction is located between the printing positions in the forward direction, the dot (printing) interval in the digit direction of the recording medium 7 Becomes narrower. That is, it is possible to form a high-density elaborate graphic having a large number of dots per unit area of the recording medium 7.

FIG. 14 shows a second embodiment. By switching the excitation method, two-phase excitation drive is executed at the time of printing ANK characters, and 1-2 phase excitation drive is executed in the case of graphics. , The print quality is to be changed, and when printing ANK characters, FIG.
And, as shown in FIG. 14B, in order to move the recording medium 7 by one dot in the row direction, the paper feed motor 6c as the step motor in the paper feed mechanism 6 is excited in two phases and printing is performed. When the pin 13 arrives at the U-turn section Tu at the swinging end, as shown in FIG.
Reverse excitation is performed by 1. That is, in the case of a four-phase step motor, two phases out of the four phases (φ1, φ2, φ3, φ4) are excited at the same time, and they are excited by shifting one phase by time. For example, as shown in FIG. 14B, at the print timing in the forward direction of the print pin 13 (see FIG.
4 (a)), two phases (φ1, φ2) are excited during the time t9 for printing 8 dots on the print pin 13 and then the phases (φ2, φ3) are excited only for t10 hours. 2 phase excitation is performed, but after that, the time of t11 is (φ1,
After performing the antiphase excitation (φ2) to excite the phase (becomes the opposite phase when viewed from the point of time t10), at the print timing in the backward direction (see FIG. 14A), the section t12 is (φ2, Return to forward two-phase excitation in the manner of φ3).
By doing so, as shown in FIG. 14C, the print pin 13 moves the recording medium 7 to the 1 position in the U-turn section Tu at the swinging end.
For example, the paper can be fed by (1/72) inch in the row direction at a step angle of dot (θo). That is, when the paper feed is executed in the two-phase forward excitation step, the inertia of the rotor of the step motor is too large, and the paper may be fed beyond the one dot. In order to eliminate this inconvenience, in this step motor, one step of two-phase excitation drive in the forward direction is performed, and then one step of anti-phase excitation drive is performed, so that the inertial force rotating in the forward direction is eliminated. The braking force in the reverse direction is applied to the rotor of the step motor, and the recording medium 7 can be accurately fed in the row direction by one dot, for example, (1/72) inch.

In the case of graphics, FIG.
As shown in FIG. 14D and FIG.
Switch to phase excitation drive. In this case, one reciprocation (t) of the swing of the print pin 13 in the lateral direction (column direction) of the recording medium 7 is performed.
After the excitation of 13) is performed at (φ1, φ2), the recording medium 7 corresponds to one dot (half the step angle in the case of the ANK character, 1 / 2θo), for example, (1/144) inches in the row direction. When the paper is fed to, the section (t14) is driven in the two-phase excitation in the forward direction of (φ2, φ3), and then the section (t15) is driven in the opposite phase of (φ1, φ2). Then, the next one reciprocation of the swing of the print pin 13 (t1
For example, the excitation of 6) is performed by the (φ2) one-phase excitation drive, and the two-phase excitation and the one-phase excitation are alternately performed for each reciprocation of the swing of the print pin 13, but the Recording medium 7
When the paper is fed, the reverse phase excitation is performed after the forward direction excitation. As a result, the paper feeding of the recording medium can be performed finely and smoothly.

At this time, the printing position F by the printing pin 13 when moving the printing pin 13 in the forward direction and the printing position R by the printing pin 13 when moving the printing pin 13 in the backward direction. Is printed so as to be displaced by an appropriate distance with respect to the lateral direction (column direction) of the recording medium 7. For example, as shown in FIG. 14C, when the printing position in the backward direction is located between the printing positions in the forward direction, the dot (printing) interval in the digit direction of the print-receiving medium 7 Becomes narrower. That is, it is possible to form a high-density elaborate graphic having a large number of dots per unit area of the print-receiving medium 7.

When the main guide piece 31 comes to the U-turn section Tu at the right swing end or the left swing end, the tips of the respective print pins 13 which are largely curved are the side surfaces or the sides of the guide holes in the main guide piece 31. The amount of swinging amplitude of the support member 14 is limited in order to prevent twisting at the edges. In this embodiment, the total amplitude amount 2a at the tip of each print pin 13 is 3.1 mm.
Is set to. Also, one printing pin 1
In the width direction (printing digit direction) of the recording medium 7, 8 dots can be printed within the total amplitude amount 2Pa = 2.8 mm for printing, whereby alphabetic characters, numerals, katakana (above The character type is called ANK) is set to be printable.

At this time, the distance H2 from the tip of the print pin 13 to the lateral pin 36 is the total length of the print pin 13 (the distance H1 from the mounting portion of the print pin 13 to the arm 22 to the tip of the print pin 13). Set to be within 30% of. In this embodiment, the position of the lateral pin 36 is preferably within 15 mm from the tip of the printing pin 13 having a total length of 50 mm, and more preferably within 10 mm. In this way, the height position of the horizontal pin 36, which is the point of action for transmitting the rocking force from the rocking interlocking mechanism 15 to the support member 14, is brought closer to the tip side of the printing pin 13, so that the main guide piece of the support member 14 is moved. The difference between the total swing amount of 31 and the actual swing amount of the tip of the printing pin 13 is reduced.

Further, a sensor piece 44, which is a sensor means for detecting the print timing of the print pin 13, is arranged along the main guide piece 31 near the tip of the print pin 13, and is integrated with the main guide piece 31. Since it swings to the right, the printing timing can be accurately detected in accordance with the actual swinging motion of the tip of the printing pin 13. Further, the sensor means is
As described above, the non-contact light transmission type detector 4 for the long sensor piece 44 and the forward slit portion 46a and the backward slit portion 46b formed in the sensor piece 44 is provided.
Since the linear encoders 7a and 47b are used, it is possible to accurately detect the reciprocating print timing without a detection error due to the short swing U-turn when swinging sinusoidally. .

Further, since the print pins 13 arranged in a line are simultaneously swung with a constant amplitude, the pair of left and right flexible columns 30, 30 and the tips of the columns 30, 30 are connected. Gate-shaped support member 1 including a main guide piece 31
4 can be swung left and right, and the printing pin 1
Since the swing amplitude amount of 3 is about one character, which is small, the inertia force at the time of swing can be small, and the speed-increasing transmission gear mechanism 43 can be formed compactly.
It has the effect of requiring less driving horsepower.

[0044]

As described above, according to the shuttle printer of the invention described in claim 1, the shuttle printer of the invention described in claim 1 has a plurality of unit printing mechanisms for moving the printing pins forward and backward. A shuttle printer in which the printing pins are arranged in a line, and the printing pins are driven while reciprocally swinging at a constant cycle in a direction intersecting with the feeding direction of the recording medium. If a stepping motor is used as the driving means of the paper feeding mechanism and the control is performed such that during the printing operation, the forward-direction excitation of two steps is followed by the anti-phase excitation of one step, the forward rotation is performed. A braking force in the direction opposite to the inertial force is applied to the rotor of the step motor, which has the effect of accurately feeding the recording medium by one dot in the row direction.

According to a second aspect of the invention, in the shuttle printer according to the first aspect, control is performed so that the reverse-phase excitation of the step motor is not performed during the paper feeding operation during non-printing. That is, when a large amount of paper feeding of the recording medium is required such as a line feed operation or a page break operation, if two-phase excitation is performed and only forward drive is performed,
Paper can be fed at high speed with high torque.

The invention described in claim 3 is the same as claim 1
In the shuttle printer described in paragraph 1, the step motor is configured to realize a minimum unit of paper feed amount by one-half rotation of the step angle, the two-phase excitation drive control of the step motor, and the 1-2 phase The selection means for controlling the excitation drive is provided. Therefore, if the 1-2 phase excitation drive control is selected, the recording medium is fed in the minimum unit of the paper feed amount, so printing can be performed with a narrow print dot interval.
Paintings that require fine dots (high print quality) can be clearly recorded, while selecting the two-phase excitation drive control has the effect of quickly executing ANK character printing and line feed operations.

[Brief description of drawings]

FIG. 1 is a side sectional view of a shuttle printer.

FIG. 2 is a plan view taken along line II-II of FIG.

FIG. 3 is a perspective view of a main part of a print head.

FIG. 4 is a partially cutaway front view of the print head.

5 is a view taken along the line VV of FIG.

FIG. 6 is a perspective view of a unit printing mechanism.

7 is a front view of the swing connecting portion and the swing mechanism taken along the line VII-VII in FIG.

FIG. 8 is an explanatory diagram showing a relationship between a slit interval and a print dot interval.

FIG. 9 is a functional block diagram of a control device.

FIG. 10 is a diagram showing a positional relationship between a print pin and a main guide piece and a curved state of the print pin.

FIG. 11 is an operation explanatory view showing the swing amplitude and the like of the print pin.

FIG. 12A is a time chart of print timings in the forward direction and the backward direction when printing ANK characters,
(B) is a two-phase excitation drive at the time of printing ANK characters, and is a time chart showing a four-phase excitation sequence in which one step of reverse excitation is performed after two steps of forward excitation,
(C) is a time chart showing the amount of movement in the paper feed direction at the time of printing ANK characters and paper feed of 1 dot by the step angle θo, and (d) is the case of only two-phase forward excitation at line feed etc. It is a time chart which shows the excitation sequence of four phases.

FIG. 13A is a time chart of print timings in a forward direction and a backward direction during graphic printing,
(B) is a two-phase excitation drive at the time of printing a graphic, and is a time chart showing a four-phase excitation sequence in which one step of forward direction excitation is followed by one step of backward direction excitation.
(C) is a time chart showing the amount of movement in the paper feeding direction between the printing of graphics and the paper feeding of one dot by the step angle θo.

FIG. 14A is a time chart of print timings in forward and backward directions when printing ANK characters,
(B) is a two-phase excitation drive when printing ANK characters, and is a time chart showing a four-phase excitation sequence in which one step of forward direction excitation is followed by one step of backward direction excitation.
(C) is a time chart showing the amount of movement in the paper feed direction when printing ANK characters and when feeding one dot of paper in the step angle θo, and (b) is the 1-2 phase excitation drive during graphic printing. Then, when feeding 1 dot of paper, a time chart showing a four-phase excitation sequence in which 1 step of forward excitation and 1 step of backward excitation are executed, (c) shows the case of graphic printing and 1 dot of paper feeding. 7 is a time chart showing a movement amount in the paper feed direction by a step angle θo.

[Explanation of symbols]

 1 shuttle printer 2 print head 6 paper feed mechanism 6c paper feed motor 7 recording medium 8 platen 11 base body 12 unit print mechanism 13 print pin 13a print dot 14 support member 15 swing mechanism 42 swing motor

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[Procedure amendment]

[Submission date] April 28, 1995

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Fig. 14

[Correction method] Change

[Correction content]

FIG. 14A is a time chart of print timings in forward and backward directions when printing ANK characters,
(B) is a two-phase excitation drive when printing ANK characters, and is a time chart showing a four-phase excitation sequence in which one step of forward direction excitation is followed by one step of backward direction excitation.
(C) is a time chart showing the amount of movement in the paper feed direction by the step angle θo when printing ANK characters and when feeding one dot of paper, and (d) is the 1-2 phase excitation drive during graphic printing. , A time chart showing a four-phase excitation sequence in which one step of forward excitation is followed by one step of backward excitation at the time of feeding one dot, and (e) shows the case of graphic printing and one dot feeding. 7 is a time chart showing a movement amount in the paper feed direction by a step angle θo.

Claims (3)

[Claims] 1. A plurality of unit printing mechanisms for moving a printing pin back and forth are arranged in a line, and printing drive is performed while reciprocally swinging the printing pin at a constant cycle in a direction intersecting a feeding direction of a recording medium. In the shuttle printer configured as described above, a step motor is used as a drive unit of the paper feeding mechanism for the recording medium, and during the printing operation, two steps of forward direction excitation are followed by one step of reverse phase excitation. A shuttle printer characterized by being controlled to execute. 2. The shuttle printer according to claim 1, wherein during the paper feeding operation during non-printing, the stepping motor is controlled so as not to perform reverse phase excitation. 3. The step angle of the step motor is 1 /
It is configured to realize the minimum unit of the paper feed amount by two rotations, and is provided with a selection unit for controlling the two-phase excitation drive and the one-two-phase excitation drive of the step motor. The shuttle printer according to claim 1.