JPS6326710B2 - - Google Patents

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention provides a platen having a plurality of protrusions extending in the axial direction on its outer circumference and being continuously rotationally driven; The present invention relates to a method for controlling a cross-hammer head printer having a printing hammer that moves parallel to the platen and a printing head that is moved parallel to the platen.

[Prior Art] Conventionally, a platen has a plurality of protrusions extending in the axial direction on its outer periphery and is driven to rotate continuously, and a printing hammer that faces the protrusions intersectingly and is connected to the platen. For example, Japanese Patent Laid-Open No. 49-43531 discloses a cross-hammer print printer equipped with a print head that can be moved in parallel. This type of dot printer differs significantly from other types of printers, such as wire printers, in that the position of the dots formed is determined by the relative intersection of the print head hammer and the platen protrusion. . For this purpose, it is required to drive the printing hammer by detecting the position of the protrusion of the platen relative to the printing hammer. For example, in the above conventional technology, a first slit disk is provided on the shaft of the platen drive motor, and a print timing signal is obtained by a first photo sensor that cooperates with the first slit disk. . The printing timing signal was one in which slits were regularly carved at equal pitches on the first slit disk so as to provide clock pulses at constant pulse intervals. Furthermore, a gate circuit is provided that allows a predetermined number of pulses (the number of vertical dots in the dot matrix of the character to be printed) to pass through while the protrusion of the platen during rotational displacement faces the printing hammer. It is adapted to be opened and closed by a second photo sensor cooperating with a second slit disk on the shaft. The pulse from the first photo sensor that has passed through the gate circuit shifts the shift register in which print data from the character generator is written, thereby driving the print hammer.

[Problems to be Solved by the Invention] According to this conventional configuration, in order to form dots at correct positions, it is necessary to finely adjust the phase of each of the first slit disk and the second slit disk with respect to the protrusion of the platen. Fine adjustment of the phase between both slit disks is required, and this fine adjustment requires a great deal of time and effort. In particular, it is possible to completely eliminate the phase shift between the first slit disk and the second slit disk.
This is almost impossible due to individual manufacturing errors in the transmission gears between the drive motor and the platen, bumps between each gear, etc., but if this phase shift occurs, the printing result may differ from the desired character shape. This can be easily understood from the printing principle of a crosshammer dot printer.
Since cross-hammer dot printers can form characters with a single printing hammer, they have a simpler configuration than wire printers and have the advantage of being able to be manufactured at low cost, but they have not been put into practical use until now. The biggest reason for not doing so is the above reason.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to solve the above-mentioned problems in cross-hammer dot printers and to provide a control method for cross-hammer dot printers that can be put to practical use.

[Means for Solving the Problems] The most important feature of the method of controlling a cross hammer print printer according to the present invention is that a blank pulse portion and a plurality of pulses that occur following the blank pulse portion and that define the tolerance position between the protrusion and the printing hammer are A print timing signal consisting of pulses is generated periodically in conjunction with the rotation of the platen.
Then, the pulse interval of this print timing signal is measured via a timer to detect a blank pulse portion, and after detecting the arrival of the first blank pulse portion after the print head has started, it is synchronized with the above pulse. The printing hammer is selectively driven.

[Embodiment] Hereinafter, a preferred embodiment of the method for controlling a cross hammer dot printer according to the present invention will be described with reference to the drawings.

1 and 2, a drum-shaped platen 1 is fixed to a platen shaft 2 and is continuously rotated clockwise in FIG. In this embodiment, the platen 1 has a length approximately corresponding to the width of the recording paper 17, and has a plurality of protrusions 3 (12 in this embodiment) extending in parallel along the axial direction of the platen 1.
is formed linearly on its outer peripheral surface. The print head 4 is disposed in front of the platen 1 and faces the platen 1 so as to move back and forth in its axial direction, that is, in a direction perpendicular to the direction in which the recording paper 17 is fed. The carriage 5 on which the print head 4 is mounted is made of a non-magnetic lightweight material and is fitted into the guide shafts 6, 7 so as to be slidable thereon.
The printing hammer 8 is used to form dots on the recording paper 17 in cooperation with the protrusion 3 of the platen, and an electromagnetic drive device 9 for causing the printing hammer 8 to collide with the protrusion 3 is connected to the carriage 5. It is provided on the back side of the.

The printing hammer 8 and the electromagnetic drive device 9 are each configured as follows, according to this embodiment, which is merely illustrated as an example.

The printing hammer 8 consists of a leaf spring 10 whose lower end is fixed to the carriage 5 in a cantilevered manner, and a striking member 11 which is fixed to the upper end of the leaf spring 10. It extends at a certain inclination angle with respect to the feeding direction of the recording paper 17 so as to crosswise face one of the protrusions 3 located in the front, and has a length slightly larger than the height of the printed character. It's just that. The electromagnetic drive device 9 is
A cylindrical outer magnetic pole 12 with a bottom, a strong rare earth permanent magnet 13 such as samarium cobalt fixed to the bottom thereof, an inner magnetic pole 14 fixed to the front surface of this permanent magnet 13, and fixed to the leaf spring 10. The moving coil 15 is inserted into the magnetic flux gap between the outer magnetic pole 12 and the inner magnetic pole 14.

The ink ribbon 16 is the striking member 1 of the printing hammer 8
1, and this ink ribbon 16
The recording paper 17 is guided by paver guides 18 and 19 between the platen 1 and the platen 1, and is fed in the direction of the arrow in FIG.

Furthermore, in FIG. 1, a rotating shaft 20 is rotationally driven by a motor (not shown), and this rotating shaft 20 includes a slit disk 21 and a pinion 22. As shown in FIG. The pinion 22 meshes with a gear 23 fixed to the platen shaft 2. The detector 25 is
A light emitting element and a light receiving element (both not shown) are housed in the openings facing each other, and the outer circumference of the slit disk 21 is inserted into each of the openings. As shown in FIG. 3, the slit disk 21 has a plurality of sets (three sets in this example) on its outer periphery.
slit groups 27 are provided, and each slit group 27 has a plurality of slits 28 arranged at equal pitches. The number of slits 28 in each slit group 27 corresponds to the number M of character rows in the dot matrix of M rows and N columns, and is 7 in this example. The detector 25 generates a print timing signal b shown in FIG. 6B. The print timing signal b consists of a blank pulse part and seven subsequent pulses P _b1 , P _b2 ...P _b7 generated at equal intervals.
A cycle signal, each pulse P _b1 , P _b2
...The row position of the dot is determined by P _b7 . That is, the protrusion 3 of the platen 1 shown in FIG.
When it rotates to each position in the first row, second row, ... seventh row in the figure, pulses P _b1 , P _b2 are generated correspondingly.
…P _b7 is starting to occur.

Print timing signal b generated by the detector 25
is supplied to a timer 29 shown in FIG. The timer 29 receives the print timing signal b
It is set to measure the pulse interval of the timer 29 and generate an output pulse when the pulse does not arrive within a predetermined time. P _c0 ~
P _c5 ) is set to occur slightly before pulse P _b1 of print timing signal b. timer 29
The output pulses are also used to detect the number N of columns in the dot matrix of characters to be printed, as will be made clear in the operation description below.

In FIG. 1, the print head 4 is caused to scan left and right along the guide shafts 6 and 7 via a scanning drive means (not shown). The speed when scanning from the left home position (not shown) to the right is related to the rotation speed of platen 1, and platen 1 rotates 1/12 (12 is the rotation speed of platen 1). ), while
Print head 4 is moved a distance corresponding to one dot spacing. Further, as shown in FIG. 6, the striking member 11 of the printing hammer 8 of the printing head 4 is
It has at least a length corresponding to the height of the characters to be printed, and is inclined at an angle θ with respect to the paper feeding direction. The inclination angle .theta. of the striking member 11 is determined in relation to the scanning speed of the printing head 4, and in this embodiment, the inclination angle .theta. is set to approximately 7 DEG to 8 DEG. The reason why the striking member 11 is tilted will be fully understood from the explanation of the operation described below.

The moving coil 15 shown in FIG. 2 is connected to a drive control circuit shown by way of example only in FIG. This drive control circuit includes the aforementioned timer 29, character generator 30, shift register 31, column address counter 32, buffer circuit 33, driver circuit 34, and counter 3.
5, AND gate 36, 37, 38, 39, 4
0, OR gate 41, delay circuit 42, 43, 4
4, 45 and flip-flop circuits 46, 47
It is made up of The column address counter 32 generates an output s according to its count value, and this output s
The column of the character generator 30 is specified by . The column address counter 32 also generates outputs h and k. The logical values of the outputs h and k are "1" and "0", respectively, until the count value reaches the number of columns N of the dot matrix, that is, 5,
When the count value reaches the number of columns N, the respective logical values are inverted to "0" and "1". When the count value of the counter 35 reaches the number of rows M of the dot matrix, that is, 7, the logical value of the counter 35 is inverted from "0" to "1".
It is also reset via the delay circuit 44 and becomes "0" again after a predetermined delay time. The flip-flop 46 is set at the rising edge of the print start signal e shown in FIG. 5E, and reset at the falling edge of the output c of the timer 29. flipflop 47
is set at the rising edge of the output m of the AND gate 36, and reset at the falling edge of the signal from the AND gate 39.

Next, the printing operation of the cross-hammer dot printer configured as described above will be explained.

Although the print head 4 is located at the right end of the platen 1 in FIG.
When scanning is performed from the home position at the left end of the platen 1 to the right, the scanning is performed as follows. First, start signal a shown in FIG.
Therefore, the platen drive motor (not shown) is activated, and the drive shaft 20 shown in FIG. 1 is rotated.
Further, the platen shaft 2 is rotated via the pinion 22 and the gear 23, and the platen 1 is continuously rotated clockwise (in the direction of the arrow) in FIG. 2 at a predetermined rotational speed. The detector 25 begins to generate a printing timing signal b as shown in FIG. 5B as the corresponding slit disk 21 (see FIG. 3) rotates. Then, when the print head scan drive signal d is generated as shown in FIG. 5D, the print head 4 is activated via its scan drive means and is caused to scan rightward from the home position. When the print head 4 runs up a certain distance from the home position, a signal e is generated as shown in FIG. 5E via a home sensor (not shown) installed at a certain distance from the home position. The home sensor is for detecting when the printing head 4 has started and has passed the run-up section and the moving speed has reached a constant speed. Therefore, the generation of the signal e indicates that the printing head 4 is ready for printing. It means to have become. When signal e occurs,
Since the flip-flop 46 shown in FIG. 4 is set by the signal e, the logic value of its output f is inverted to "1" as shown in FIG. 5F. This output f passes through the OR gate 41 and the AND gate 36
AND gate 36
Open the gate. On the other hand, characters, numbers, symbols, etc. corresponding to data sent from a computer etc. are stored in a dot matrix pattern in a character generator 30 in advance, and the character generator 30 is stored in a column address counter 32.
In accordance with the column address signal s, a pattern signal for the column of the specified address corresponding to the column address signal s is generated in 7-bit parallel. Now column address counter 3
Since the count value of 2 is 0, the character generator 30 generates the pattern signal for the first column of the dot matrix pattern of the character corresponding to the sent data, and the column address counter 3
The logical values of outputs h and k of 2 are "1" and "0", respectively, as shown in FIG. 5H and FIG. 5K. In this state (the gate of the AND gate 36 is open), the timer 29 (this timer 29 is
The pulse interval of the print timing signal b output from the detector 25 is measured, and when a pulse does not arrive within a predetermined time, that is, when a blank pulse portion arrives, an output pulse is generated by time-up. ) is generated at the output c of the pulse P _c1 and supplied to the AND gate ₃₆ in FIG. flipflop 46
is reset and its output f becomes a logical value "0". As a result, the AND gate 36 generates a pulse P _n1 specifying the first column of the dot matrix pattern at its output m, as shown in FIG. 5M. For this purpose, the character generator 3 is shown in FIG.
The pattern signal of the first column of 0 is written into the shift register, and the flip-flop 47 is set by the rise of the pulse _Pn1 , and the logic value of its output r becomes "1" as shown in FIG. 5R. Become. The pulses of the print timing signal b generated by the detector 25 of FIG. 1 as shown in FIG. 5B.
P _b1 , P _b2 . . . P _b7 are supplied to the AND gate 37 in FIG. 4, but since the logic values of the other two input terminals of this AND gate 37 are both held at "1", The pulses P _b1 , P _{b2 .} . . P _b7 pass through the AND gate 37. The pattern signal written in the shift register 31 is read out from the shift register 31 by the pulses P _b1 , P _{b2 .} . . Supplied to one input terminal. In parallel with the above reading operation, the pulses P _b1 , P _b2 . . . P _b7 are supplied to the other input terminal of the AND gate 38 via the delay circuit 43. Therefore, the AND gate 38 generates a driving pulse corresponding to the pattern signal of the first column at its output n with a phase slightly delayed from the timing of generation of the pulses P _b1 , P _b2 . . . P _b7 . For example, if the data being sent to the character generator 30 corresponds to the letter "A", the AND gate 38 will
Drive pulses P ₃₁ , P ₄₁ . . . P ₇₁ are generated as shown in FIG. 5N. The drive pulses P ₃₁ , P ₄₁ ...P ₇₁ are the second
Any one of the protrusions 3 of the platen 1, which is continuously rotating in the direction of the arrow in the figure, is in the third row position, fourth row position, ... seventh row position in front of the striking member 11 of the printing hammer 8 in FIG. It is intended to occur exactly at a certain time.

On the other hand, the striking member 11, which is inclined at an angle θ, is continuously moving to the right (in the direction of the arrow) in _{FIG .} ... When P ₇₁ occurs, the protrusion 3 and the striking member 11 intersect with each other in order on the third, fourth, and seventh rows of the first column. In FIG. 4, the AND gate 38 is connected to the drive pulse as described above.
When P ₃₁ , P ₄₁ ...P ₇₁ is generated, drive pulses P ₃₁ ,
The driver circuit 34 is activated by each of P ₄₁ ...P ₇₁ and a pulsed drive current is applied to the moving coil 15. Moving coil 15
In FIG. 2, the magnetic flux in the gap between the outer magnetic pole 12 and the inner magnetic pole 14 generated by the magnetic force of the permanent magnet 13 cooperates magnetically to receive a leftward displacement force. . Due to this displacement force, the printing hammer 8 is displaced to the left against the spring force of the leaf spring 10.
The protrusion 3 of the platen 1 whose striking member 11 is rotating
As a result, at the position where the protrusion 3 and the striking member 11 cross each other and collide,
The first row of dots of the letter "A" are formed on the recording paper 17 as shown in FIG.

Here, the explanation of the printing operation will be temporarily interrupted and the reason why the striking member 11 of the printing hammer 8 is tilted will be explained.

As already explained, the striking member 11 of the printing hammer 8 is operated while being continuously moved to the right on the plane of the paper in FIG. Assuming that the striking member 11 is perpendicular to the protrusion 3, the position where the protrusion 3 and the striking member 11 intersect is
As the protrusion 3 moves downward with rotational displacement and at the same time shifts slightly to the right with the rightward movement of the striking member 11, the dots in the column direction (vertical direction) are arranged diagonally and the characters formed. is also tilted. Therefore, in this embodiment, the striking member 11 is inclined at an angle .theta. of about 7 DEG to 8 DEG so that the dots in the column direction are aligned straight in the paper feeding direction of the recording paper 17. However, this angle θ can be slightly changed depending on the design of the characters to be formed. For example, when forming the characters in italics, the angle θ may be set larger than that.

Next, the continuation of the above printing operation will be explained.

In FIG. 4, the pulse of the AND gate 36
When the writing operation by P _n1 to the shift register 31 is completed, this pulse P _n1 is transferred to the delay circuit 4.
It is counted by the column address counter 32 via 2. That is, the count value of the column address counter 32 is incremented by one, and the character generator 30 now outputs the pattern signal for the second column. The output pulse of the AND gate 37, that is, the pulse P _b1 of the print timing signal b,
P _b2 ...P _b7 are counted by a counter 35, and when the counted value reaches 7, that is, when the dot forming operation for that column is completed, the output g of the counter 35 becomes a logical value "1" as shown in FIG. 5G. become. At this time, the output h of the column address counter 32, which is one input signal of the AND gate 40, is held at the logical value "1", so the output j of the AND gate 40 becomes the logical value "1", and the OR gate 41 is The signal is supplied to the AND gate 36 via the signal. Here, since the pulse P _c2 of the output c of the timer 29 is supplied to the AND gate 36, the AND gate 36 generates a pulse P _n2 specifying the second column of the dot matrix as shown in FIG. The counter 35 is reset via the delay circuit 44, and then the second column of dots is formed in the same manner as described above. This second row of dots is formed by the striking member 11 and a projection following the projection 3 in the first row. Thereafter, the same operation is repeated to form dots in the third, fourth, and fifth columns, and characters in a dot matrix of 7 rows and 5 columns are formed as shown in FIG.

When the column address counter 32 counts up 5 in FIG. 4, its outputs h and k are inverted to logical values "0" and "1", respectively, as shown in FIGS. 5H and 5K. Therefore, the output pulse P _g5 of the counter 35 after the printing operation of the fifth column is completed is sent to the AND gate 39 as shown in FIG.
A pulse P _l is generated as shown in . The column address counter 32 and flip-flop 47 are both reset by the fall of this pulse _Pl . Therefore, the column address counter 32
The output signals h and k of are again the logical value "1", respectively.
The output signal r of the flip-flop 47 returns to "0", and the output signal r of the flip-flop 47 becomes a logical value "0". In addition, the above pulse P _l
is delayed by the action of the delay circuit 45 as a pulse P′ _l shown by a broken line, and is supplied to the AND gate 36 via the OR gate 41. Therefore, even if the pulse P _c0 arrives at the AND gate 36 after a certain character is printed, the AND gate 36 does not generate a pulse as shown in FIG. 5M. Then, when the next pulse P _c1 arrives, the AND gate 36 generates the pulse P _n1 . That is, as shown in FIG. 6, the next character is formed in the same manner as described above after leaving a space between characters corresponding to one dot row.

It goes without saying that the printing head 4 is not limited to the moving coil type. Furthermore, the detector 25 that generates the print timing signal can be appropriately selected from a magnetic sensor type or a sliding brush type instead of a photo sensor type.

[Effects of the Invention] According to the present invention described in detail above, a platen having a plurality of protrusions extending in the axial direction on the outer circumference and being continuously rotationally driven; In a cross-hammer print printer having a hammer and a print head that is continuously moved in parallel with the platen, synchronization of rotation of the platen and driving of the print hammer can be controlled by a single detector. This eliminates the need for fine phase adjustment between the first slit disk and the second slit disk and the phase adjustment of the second slit disk relative to the protrusion of the platen as in the prior art.
Moreover, no phase shift occurs. Therefore, the effect of contributing to the practical application of such a cross-hammer dot printer, its manufacturing, and quality control is enormous.

[Brief explanation of the drawing]

The drawings relate to an embodiment of a method for controlling a crosshammer dot printer according to the present invention.
Figure 1 is a front view showing the mechanical configuration of the cross hammer print printer, Figure 2 is a sectional view taken along the line shown in Figure 1, Figure 3 is an enlarged front view of the slit disk, and Figure 4 is the print head drive control circuit. 5 is a time chart thereof, and FIG. 6 is an enlarged explanatory diagram of printed characters. DESCRIPTION OF SYMBOLS 1...Platen, 3...Protrusion, 4...Print head, 8...Print hammer, 9...Electromagnetic drive device,
17...recording paper, 21...slit disk, 25...
...Detector, 29...Timer, P _b1 , P _b2 ~ _{P b7} ...
Print timing signal pulse.

Claims (1)

[Scope of Claims] 1. A platen having a plurality of protrusions extending in the axial direction on its outer periphery and being driven to rotate continuously, and a printing hammer intersectingly facing the protrusions and parallel to the platen. In a cross-hammer print printer equipped with a print head that is continuously moved to a print head, a print timing signal consisting of a blank pulse portion and a plurality of pulses that occur subsequently and define the intersecting position of the protrusion and the print hammer. of,
The blank pulse portion is generated periodically in conjunction with the rotation of the platen, and the pulse interval of the print timing signal is measured via a timer to detect the blank pulse portion, and the first blank pulse portion after the print head is started. 1. A method for controlling a cross-hammer dot printer, characterized in that the printing hammer is selectively driven in synchronization with the pulse after detecting the arrival of the pulse.