JP2000335012A - Impact printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To arrange the impact positions to a platen at every printing pins in a row direction. SOLUTION: The shift quantities of the impact positions to a flat plate-shaped platen at every printing pins in a line direction when a plurality of printing pins a-g are driven in the same timing are preliminarily stored in a memory means. The drive timings at every printing pins are controlled on the basis of the moving speed of a printing head in a line direction and the shift quantities of the impact positions at every printing pins in the line direction by a control means. At first, the printing pins (b), (f) are driven and, after a P1d time, the printing pin (d) is driven and, after a P2d time, the printing pin (c), (e) are driven and, after a P3d time, the printing pins (a), (g) are driven. The return of the printing pins is performed in the same order.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an impact type printing apparatus having a dot impact type printing head and performing printing while scanning in a row direction.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 6 (a) and 6 (b), a plurality of printing pins a to g are provided in a row direction, and a plurality of design platens (cylindrical platens) A having a predetermined shape are provided on the back. Dot impact type print head B, in which when the print pins are driven at the same timing, the arrangement of the print pins when they land is a straight line
While scanning the print head B in the row direction, selectively print pins a to g at the same timing toward a print target P such as paper passing through a gap between the platen A and the print head B. There is a printing device that drives and prints. In this case, the print pins a to g are arranged so as to be inclined and protrude at a predetermined angle, and the impact positions of the print pins on the paper are arranged in one line vertically with respect to the center line as shown in FIG. They are aligned.

[0005] However, such a printing apparatus is not shown in FIG.
As shown in FIG. 7B, when a specific platen (flat platen) D having a different shape from the design platen is to be printed on the surface of a flat time card C at the same timing as when the design platen is used, FIG. As shown in (c), the landing position of the tip of the print pin is not aligned in one vertical line with respect to the center line, but is slightly shifted left and right in the row direction. That is, the printing accuracy is reduced.

Therefore, a print head B and a platen platen D
To adjust the time card C
Attempts have been made to adjust the landing position of the print pins by adjusting the distance at which the print pins a to g land on the surface of the surface, thereby improving the vertical arrangement of the print pins at the time of landing.

[0005]

However, even with the above-mentioned attempts, it is difficult to align the landing positions neatly in a vertical line.

Further, in order to newly develop a print head capable of printing finely on the surface of a flat time card C having a flat platen D as a back, there is a problem that the product cost is greatly increased. was there. Furthermore, this problem is solved by using a dot impact type print head in which when a plurality of print pins are driven at the same timing with a design platen of a predetermined shape at the back, the arrangement of the print pins when they land is straight. This is a common problem that occurs when printing is to be performed on the back of a specific platen having a different shape from the design platen.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a method of driving a plurality of print pins at the same timing, and arriving at each of the print pins for a specific platen actually used. The shift amount of the position in the line direction is stored in advance in the storage means, and the ejection timing for each print pin is determined based on the moving speed of the print head in the line direction and the shift amount of the landing position for each print pin in the line direction. , The landing positions of the print pins can be aligned vertically. Therefore, it is possible to prevent the deterioration of the printing accuracy that occurs when the dot impact type print head developed for the design platen is printed with the specific platen having a different shape from the design platen as a back side. Further, the versatility of the dot impact print head developed for the design platen is increased. That is, the problem that the dot impact print head developed for the design platen can be used only for the design platen can be solved.

Further, the present invention controls the motor so that the moving speed of the print head in the row direction becomes a predetermined planned moving speed, and sets the ejection timing for each print pin to the predetermined moving speed and the printing speed. The control unit controls the impact position in the row direction for each pin. With this configuration, the control for aligning the landing positions of the print pins vertically and easily can be easily performed. Therefore, it is possible to prevent the deterioration of the printing accuracy that occurs when the dot impact type print head developed for the design platen is printed with the specific platen having a different shape from the design platen as a back side. Also, the versatility of the dot impact print head developed for the design platen is increased. That is, the problem that the dot impact print head developed for the design platen can be used only for the design platen can be solved.

Further, according to the present invention, the ejection timing of each print pin is controlled by a control means based on the moving distance of the print head in the row direction and the shift amount of the impact position of each print pin in the row direction. I have. This configuration can solve the same problems as above,
Control for aligning the landing positions of the print pins vertically can be easily performed without calculating the moving speed of the print head.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The impact type printing apparatus of the present invention has a plurality of printing pins in a row direction, and the printing is performed when the plurality of printing pins are driven at the same timing with a design platen having a predetermined shape as a back. A dot impact type print head in which the arrangement of the pins at the time of landing is a straight line, a scanning mechanism for scanning the print head in the row direction, and a motor for driving the scanning mechanism, wherein the print head is moved in the row direction. An impact-type printing apparatus that performs printing while scanning, wherein the actually used platen is a specific platen having a different shape from the design platen, and the specific platen when the plurality of print pins are driven at the same timing. Storage means for storing in advance the shift amount in the line direction of the impact position of each print pin with respect to the print position, and the moving speed of the print head in the line direction. Serial based on the shift amount in the row direction of the landing position of each printing pin, and a control means for controlling the launch timing for each said printing pins.

The control means controls the motor so that the moving speed of the print head in the row direction becomes a predetermined planned moving speed, and controls the planned moving speed and the impact of each print pin. It is characterized in that the ejection timing for each of the print pins is controlled based on the shift amount of the position in the row direction.

It is preferable that the control means further includes means for detecting a moving speed of the print head in the row direction.

Further, the control means controls the ejection timing of each print pin based on a moving distance of the print head in the row direction and a shift amount of a landing position of each print pin in the row direction. It is characterized by.

Preferably, the control means further includes means for detecting a moving distance of the print head in the row direction.

Further, the design platen is a cylindrical platen, and the specific platen is a flat platen.

[0016]

An embodiment of the present invention will be described below.

As shown in FIG. 1, a roller shaft 2 is provided in the vicinity of an upper portion of a frame 1 so as to be rotatable in a horizontal posture.
Pinch rollers 2a, 2a are fixed to the roller shaft 2 at positions corresponding to the vicinity of both sides of the time card C. A roller (not shown) forming a pair with the pinch rollers 2a, 2a is rotatably provided on the opposite side of the surface of the time card C facing the roller shaft 2, and the time card C is rotated by forward and reverse rotation of the roller shaft 2. Can be moved up and down. A wheel train R1 for transmitting the rotation of a DC motor (card feed motor) 8 to the roller shaft 2 to move the time card C in the vertical direction is provided on the front left side of the frame 1.

The structure of the wheel train R1 will be briefly described by going up from the roller shaft 2 side to the drive side.

A roller shaft driving gear 3 is fixed to the roller shaft 2, and a pinion 4a integral with the first intermediate wheel 4 meshes with the driving gear. A second intermediate wheel 5 meshes with the first intermediate wheel 4, and a pinion 6a integral with the third intermediate wheel 6 further meshes with this intermediate wheel. Third intermediate wheel 6
Are engaged with the motor gear 7. The motor gear 7 is fixed to a motor shaft 8 a of a card feed motor 8 attached to a lower portion of the frame 1. Therefore, the forward / reverse rotation of the card feed motor 8 is transmitted to the roller shaft 2 via the wheel train R1, so that the time card C is drawn in or pulled up.

The second intermediate wheel 5 has a rotating plate 9 concentric therewith.
Are provided so as to be integrally rotatable. Radial through holes (not shown) are formed at equal intervals inside the outer peripheral portion of the rotating plate 9.
Is provided. An interrupter-type optical sensor 10 is provided at one location near the outer peripheral portion of the rotating plate 9 so as to sandwich the rotating plate, and through holes of the rotating plate 9 allow light from the optical sensor 10 to pass or block. Or so. That is, by the rotating plate 9 and the sensor 10,
A detection unit (encoder) 11 for converting the rotation amount of the card feed motor 8 into a pulse signal is configured. The data signal output from the detecting means 11 is supplied to a control circuit 25 described later.

In the vicinity of the upper portion of the frame 1, a card slot 12 for receiving a time card C is provided.
A card insertion detection switch 13 is provided at the center of the time card C. A pair of card sensors 14 and 14 constituting card detection means at card reference positions are provided at positions sandwiching both sides of the time card C. I have.

Below the roller shaft 2, there is provided a print head 15 for printing the date and time in the print column C1 of the time card C. The print head 15 has a plurality of print pins in the column direction, and the plurality of print pins are the same with a design platen A (in this example, a cylindrical platen) A having a predetermined shape as shown in FIG. When driven at the timing, the arrangement of the printing pins upon landing is a straight line. In this example, as shown in FIG. 7, a specific platen having a shape different from the design platen A (in this example, a flat platen is used). .) D is printed on the back, is mounted on the carrier 16, and can be reciprocated in the horizontal direction (scanning direction of the print head) along the guide pillar 17 by driving of the carrier driving motor 18. A lead screw 19 rotatably supported by the frame 1 is provided in the vicinity of the guide post 17, and a train R2 for transmitting the rotation of the carrier driving motor 18 to the lead screw 19 is provided on the right side of the front of the frame 1. It is provided in. The configuration of the wheel train R2 is the motor gear 1 of the motor 18.
A reduction gear 20 and a switching gear 21 are sequentially meshed with 8a, and a lead screw drive gear 19a fixed to the lead screw 19 is meshed with the switching gear 21. Therefore, the rotation of the carrier driving motor 18 is controlled by the wheel train R
The carrier 16 is moved by being transmitted to the lead screw 19 through the print head 2 to enable printing by the print head 15.

The motor gear 18a is provided with a rotating plate 22 concentric therewith so as to be integrally rotatable. The rotary plate 22 is provided with radial through holes (not shown) at equal intervals inside the outer peripheral portion. An interrupter-type optical sensor 23 is provided at one position near the outer peripheral portion of the rotating plate 22 so as to sandwich the rotating plate, and a through hole through which the rotating plate 22 rotates allows light from the optical sensor 23 to pass or block. Or so. That is, the rotating plate 22 and the optical sensor 2
3 constitutes a detecting means (encoder) 24 which detects the rotation of the carrier driving motor 18 and converts it into a pulse signal for obtaining the moving speed of the carrier 16. The data signal output from the detecting means 24 is
The ejection timing is controlled for each print pin of the print head 15 according to the moving speed of the carrier 16, that is, the moving speed of the print head 15 in the row direction.

Therefore, when the time card C is inserted from the card insertion slot 12, the card insertion detection switch 1
3 detects the lower end of the time card C, starts driving the card feed motor 8, and starts the operation of drawing in the time card C. During this pull-in operation, the card detecting means 14
Detects the upper end of the time card C, the stop control of the card drawing operation is performed.

Thereafter, the card feed motor 8 starts to be driven in the reverse direction to start raising the time card C to the target printing position, and when the card detection means 14 detects the upper end of the time card C again, With the position as the reference position of the time card C, stop control of the raising operation of the time card C to the print target position is performed.

When the time card C stops at the printing target position, the driving of the carrier driving motor 18 is started, and the lead screw 19 is driven via the motor gear 18a, the reduction gear 20, the switching gear 21, and the lead screw driving gear 19a.
To rotate. The rotation of the lead screw 19 causes the carrier 16 to move in the horizontal direction along the guide post 17, so that the print head 15 provided on the carrier 16 is scanned in the row direction in accordance with the movement of the carrier, and will be described later in detail. The printing process as described is performed, and desired printing such as date and time is performed on the printing column C1 of the time card C.

The printing process is performed by a control circuit 25 based on an output signal from an encoder 24 comprising a rotating plate 22 and an optical sensor 23 for detecting the rotation of the carrier driving motor 18.
, The moving speed or moving distance of the print head 15 in the row direction is obtained, and the ejection timing for each of the print pins a to g of the print head 15 is controlled according to the moving speed or moving distance of the print head 15.

FIG. 2 is a block diagram showing the configuration of the impact-type printing apparatus. The output from the above-described card detecting means 14 is supplied to a control circuit (CPU) 25 which forms a central portion of the motor control apparatus. A signal can be input, and a drive signal for a print pin is supplied to the print head 15 described above. The control circuit 25 includes a CPU 25a, an RO
M25b and RAM 25c are provided. The detection unit 24 is an encoder including the above-described rotating plate 22 and the optical sensor 23, and detects the rotation of the carrier driving motor 18. As for the output of the optical sensor 23, a signal of 6 pulses is obtained per one rotation of the carrier driving motor 18, and the carrier advances by 1.8 mm. The output of the optical sensor 23 is supplied to the control circuit 25,
By measuring the period of this signal, the carrier 16
The moving speed of the (print head 15) is calculated. As the moving speed, the average value t of the moving speeds of the latest four pulses of the output of the optical sensor 23 is always used. The average value t is stored in a first storage circuit 27a, which will be described later. Therefore, the latest storage speed t is always stored in the first storage circuit 27a.

The control circuit 25 can process various data in the CPU 25a in accordance with the operation program stored in the ROM 25b, and can output the result to the motor drive circuit 26 and the like. Further, the RAM 25c stores various data such as a print position and a print content of the time card,
The detection result by the detection means (encoder) 24 is stored.

In the control circuit 25, a storage means 27 is provided so as to be able to exchange data. The storage means 27 has three storage circuits.

That is, the latest moving speed t of the carrier 16 described above is stored in the first memory circuit 27a, and the moving speed t is read from the first memory circuit 27a by the control circuit 25, and the motor driving circuit 26, the carrier driving motor 18 is driven to rotate.

The shift amounts P1, P2, P3 in the row direction of the landing positions of the print pins a to g shown in FIG. 7C and shown in FIG. 3 are previously stored in the second storage circuit 27b. . This shift amount is a value obtained by measuring in advance an experiment as described later.

Further, the third storage circuit 27c calculates the shift amount in the row direction as the average value t of the carrier moving speed described above.
Time P for each printing pin obtained by dividing by
1d, P2d, and P3d are stored. As described above, since the average value t is always rewritten to the latest data, the launch deviation time corresponding to this deviation amount is always rewritten to the latest data.

With reference to FIG. 3, the displacement amounts P1 to P3 of the landing positions of the print pins in the row direction will be described in detail. As described with reference to FIG. 6 and FIG.
Reference numeral 5 denotes a flat platen having a shape different from that of the cylindrical platen A because a plurality of print pins are driven at the same timing on the back of the cylindrical platen A, and the arrangement of the print pins at the time of landing is linear. When a plurality of print pins are driven at the same timing with B as the back, the landing positions of the print pins are not aligned clearly in one vertical column, and are slightly shifted in the row direction as shown in FIG. Assuming that the scanning direction of the print head 15 is the right direction as shown by the arrow, the print pins b and f land first, the print pin d next land at a position shifted by a distance P1 from the landing position, and further from there. Print pin c at a position shifted by distance P2
And e land next, and the print pins a and g land further at a position shifted by the distance P3 therefrom. Therefore, the print head 15 moves the shift amount P1 with respect to the print pin that lands first.
If the driving is delayed by the time required to move by P2 and P3, that is, by the time obtained by dividing the respective shift amounts P1, P2 and P3 by the average value t of the moving speed, the landing positions are aligned in one vertical line. Can be. In this example, the shift amounts P1, P2, P
3 is measured in advance, and the distance measurement result is stored in the second storage circuit 27b in advance.

[0035]

[Explanation of Operation] FIG. 4 shows the timing of ejection for each print pin. The position of the carrier 16 is detected from the number of pulses of the optical sensor 23. When the carrier reaches the target print position, first the print pins b and f are output. The driving signal is supplied to start launching. Then, a driving signal for the print pin d is supplied and the recording is performed at a time delayed by P1d. Then, P2d
The drive signals for the print pins c and e are supplied and ejected at a time delayed. Finally, the printing pin a
And g are supplied and driven. All print pins a to g
Is completed, the printing pins a to g are pulled back in the same order.

By performing such printing control,
As shown by black circles in FIG. 5, printing is performed in which the landing positions of all the print pins a to g are aligned in a vertical line.
The print like the staggered pattern shown in (c) is improved, and clear print becomes possible. When printing is actually performed, the print pins a to g are selectively operated based on the above-described timing.

The moving speed of the print head 15 in the row direction is set in advance, and this planned moving speed is
M25b, and the control circuit 25 detects the moving speed of the print head 15 from a signal obtained by detecting the rotation of the motor 18 by the encoder 24,
b, by comparing the planned moving speed stored in b with the detected moving speed of the print head 15, and controlling the drive voltage of the motor 18 so that the moving speed of the print head 15 matches the planned moving speed. The moving speed of the head 15 is corrected, and then, based on the planned moving speed of the print head stored in the ROM 25b and the shift amounts P1, P2, and P3 for each print pin stored in the storage circuit 27. , Deviation amount P
By dividing 1, P2, and P3 by the respective predetermined moving speeds, the ejection delay times P1d to P3d are obtained, and the ejection timing for each print pin may be controlled in accordance with the ejection delay times P1d to P3d. .

In still another embodiment, the distance between the through holes of the rotating plate 22 is extremely small so that the output signal obtained from the optical sensor 23 of the encoder 24 can be obtained with fine precision. The rotation of the motor with high accuracy can be detected, and the movement distance of the print head 15 with high accuracy can be detected from this output. That is, by counting the output signals from the optical sensor 23, the moving distance of the print head 15 can be detected in detail. Based on the detected movement distance and the above-described shift amount for each print pin, the control of the ejection timing for each print pin is performed directly. That is, the optical sensor 2
The print pins are selectively driven on the condition that the number of output signals from the output signal 3 becomes in accordance with the shift amounts P1, P2, and P3. In this case, after the print pins b and f are launched, the print pin d
And after a further P2 distance, print pins c and e
, And finally print pins a and g when advanced by the distance P3. Pullback of the pins is performed in the same order as at the time of punching. In this example, it is not necessary to calculate the moving speed of the print head, and the moving distance of the print head can be directly used to control the ejection timing for each print pin.

In each of the above examples, the design platen is a cylindrical platen, and the specific platen is a flat platen. However, the present invention is not limited to this. For example, the design platen may be a cylindrical platen, and the specific platen may be a cylindrical platen having a different curvature from the design platen. However, when the present invention is used for a time clock, a print head for a cylindrical platen used in a normal printer can be applied to a flat platen of the time clock, so that a dedicated print head for the time clock must be provided. Can be eliminated.

In the above description, the number of print pins of the print head is seven. However, the present invention is not limited to this and can be changed as appropriate.

In the above, an example in which the present invention is applied to a time clock is shown. However, the present invention is not limited to the time clock but can be applied to a desired printing device.

[0042]

According to the present invention, when a plurality of printing pins are driven at the same timing, the shift amount in the row direction of the above-mentioned landing position for each printing pin with respect to the specific platen actually used is stored in the storage means in advance. In addition, since the ejection timing for each print pin is controlled by the control means based on the moving speed of the print head in the row direction and the shift amount of the landing position for each print pin in the row direction, the landing of the print pin is controlled. The positions can be aligned vertically. Therefore, it is possible to prevent the deterioration of the printing accuracy that occurs when the dot impact type print head developed for the design platen is printed with the specific platen having a different shape from the design platen as a back side. Further, the versatility of the dot impact print head developed for the design platen is increased. That is, the problem that the dot impact print head developed for the design platen can be used only for the design platen can be solved.

Also, the present invention controls the motor so that the moving speed of the print head in the row direction becomes a predetermined scheduled moving speed, and sets the ejection timing for each print pin to the predetermined moving speed and the printing speed. The control unit controls the impact position in the row direction for each pin. With this configuration, the control for aligning the landing positions of the print pins vertically and easily can be easily performed. Therefore, it is possible to prevent the deterioration of the printing accuracy that occurs when the dot impact type print head developed for the design platen is printed with the specific platen having a different shape from the design platen as a back side. Further, the versatility of the dot impact print head developed for the design platen is increased. That is, the problem that the dot impact print head developed for the design platen can be used only for the design platen can be solved.

Further, according to the present invention, the ejection timing for each print pin is controlled by control means based on the moving distance of the print head in the row direction and the shift amount of the landing position for each print pin in the row direction. I have. This configuration can solve the same problems as above,
Control for aligning the landing positions of the print pins vertically can be easily performed without calculating the moving speed of the print head.

[Brief description of the drawings]

FIG. 1 is a front view showing an example of an internal configuration of a time clock to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration of the present invention.

FIG. 3 is an impact position diagram of a conventional print pin driven by the print pin.

FIG. 4 is a timing chart of the ejection of each print pin according to the present invention.

FIG. 5 is a view showing a landing position of a print pin by driving the print pin according to the present invention.

FIGS. 6A, 6B, and 6C are schematic diagrams of a print head, a platen, and a landing position of a print pin in a conventional example using a cylindrical platen.

7 (a), (b) and (c) are schematic views showing the expected landing positions of a print head, a platen, and a print pin when printing is performed by changing the conventional cylindrical platen to a flat platen in FIG. FIG.

[Explanation of symbols]

 Reference Signs List A Design Platen D Specific Platen 15 Print Head ag Print Pin 18 Motor (Carrier Driving Motor) 19 Scanning Mechanism (Lead Screw) 24 Detecting Means (Encoder) 25 Control Circuit 26 Motor Drive Circuit 27 Storage Means 27a First Storage Circuit 27b Second storage circuit 27c Third storage circuit

Claims (6)

[Claims] 1. A dot having a plurality of printing pins in a column direction and having a design platen of a predetermined shape as a back and driving the plurality of printing pins at the same timing so that the arrangement of the printing pins at the time of landing is a straight line. An impact-type printing apparatus that has an impact-type print head, a scanning mechanism that scans the print head in the row direction, and a motor that drives the scanning mechanism, and performs printing while scanning the print head in the row direction. The platen actually used is a specific platen having a different shape from the design platen, and the line of the landing position for each print pin with respect to the specific platen when the plurality of print pins are driven at the same timing. Storage means for pre-storing the shift amount in the direction, the moving speed of the print head in the line direction and the line position of the landing position for each print pin And a control means for controlling the ejection timing for each print pin based on the amount of deviation in the impact type printing apparatus. 2. A dot having a plurality of printing pins in a column direction and having a design platen of a predetermined shape as a back and driving the plurality of printing pins at the same timing so that the arrangement of the printing pins at the time of landing is a straight line. An impact-type printing apparatus that has an impact-type print head, a scanning mechanism that scans the print head in the row direction, and a motor that drives the scanning mechanism, and performs printing while scanning the print head in the row direction. The platen actually used is a specific platen having a different shape from the design platen, and the line of the landing position for each print pin with respect to the specific platen when the plurality of print pins are driven at the same timing. Storage means for pre-storing the shift amount in the direction, and the moving speed of the print head in the row direction is set to a predetermined expected moving speed. Control means for controlling the motor and controlling the launch timing for each print pin based on the shift amount in the line direction between the planned movement speed and the landing position for each print pin. Type printing device. 3. An impact type printing apparatus according to claim 1, wherein said control means further includes means for detecting a moving speed of said print head in said row direction. 4. A dot having a plurality of print pins in a column direction and having a design platen of a predetermined shape as a back and driving the plurality of print pins at the same timing so that the arrangement of the print pins at the time of landing is a straight line. An impact-type printing apparatus that has an impact-type print head, a scanning mechanism that scans the print head in the row direction, and a motor that drives the scanning mechanism, and performs printing while scanning the print head in the row direction. The platen actually used is a specific platen having a different shape from the design platen, and the line of the landing position for each print pin with respect to the specific platen when the plurality of print pins are driven at the same timing. Storage means for storing in advance the amount of displacement in the direction, the movement distance of the print head in the row direction and the row of the landing position for each print pin And a control unit for controlling the ejection timing for each print pin based on the amount of displacement in the direction. 5. An impact type printing apparatus according to claim 4, wherein said control means further includes means for detecting a moving distance of said print head in said row direction. 6. The impact-type printing apparatus according to claim 1, wherein the design platen is a cylindrical platen, and the specific platen is a flat platen.