JPS6145952B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing method for a dot printer, and more particularly, the present invention relates to a printing method for a dot printer, and more particularly, a printing method comprising a rotary drum having a plurality of protrusions extending in the axial direction formed on the outer circumferential surface thereof and an electromagnetically driven printing hammer device. A printing head is provided in front of the rotating drum to move oppositely across the recording medium in a direction perpendicular to the feeding direction of the recording medium, and the printing hammer device is arranged to move in a direction perpendicular to the feeding direction of the recording medium. A striking member is provided which is inclined at a certain angle to the right and faces the protrusion in an intersecting manner, and the collision between the protrusion and the striking member produces dot matrix characters, etc. on the recording medium. The present invention relates to a printing method in a dot printer configured to form a dot.

Conventionally, unlike other types of dot printers, the dot printers described above had to pause printing when the print head returned to normal operation due to limitations in its structural principle, and this was one of the causes of obstacles to high-speed printing. .

The present invention provides a new printing method that enables reciprocating printing in the above-mentioned dot printer,
The purpose of this is to easily realize high-speed printing.

First, the structure of a dot printer to which the present invention is applied will be explained.

In FIG. 1, a rotating drum 2 fixed to a drive shaft 1 has a plurality of protrusions 3 (12 in this example) integrally formed on its outer peripheral surface, and each protrusion 3 extends in the axial direction of the rotating drum 2. They extend parallel to each other.
A printing head 4 is arranged in front of the rotating drum 2 to face it, and this printing head is mounted on a carriage (not shown) via a support plate 5 so that it can reciprocate in parallel with the rotating drum 2. It's getting old.

As shown in FIGS. 2 and 3, a cantilever-shaped printing hammer device 6 is provided on the front surface of the support plate 5. As shown in FIGS. In this embodiment, the printing hammer device 6 is composed of a triangular thin plate spring 7 and a plate-shaped striking member 8 attached to its free end. The thin plate spring 7 has vertically bent portions 9, 9 formed on both side edges thereof, and the striking member 8 is held between the upper ends of the vertically bent portions 9,9. The striking member 8 extends in a direction substantially perpendicular to the direction in which the protrusion 3 extends, but in this embodiment, even if the printing head 4 is continuously spaced, the dots in the matrix row are The dots are inclined at an angle θ to the right with respect to the feeding direction of the recording medium 21, that is, the arrangement direction of the dots in the row so that the dots are arranged vertically in a straight line.
The thin plate spring 7 has its lower end fixed to the holder plate 11 via caulking pins 10, 10, and the holder plate 1
1 is detachably supported by the support plate 5 via screws 12, 12. A cylindrical moving coil 13 is attached to the back surface of the thin plate spring 7 via a holder 14.

A magnetic flux generating device composed of a center yoke 15, an outer yoke 16, and a permanent magnet 17 is disposed on the back surface of the support plate 5 via screws 18, 18 shown in the second figure. The center yoke 15 has a cylindrical portion 19 protruding from the center, which is surrounded by an annular outer yoke 16, and between the rear part of the center yoke 15 and the outer yoke 16, an annular permanent magnet 17 is attached to a sand magnet. It is held in a shape. center yoke 1
5. The outer circumferential yoke 16 and the permanent magnet 17 are integrally coupled to each other via adhesive, for example. The center yoke 15 and the outer yoke 16 are magnetized with different polarities by a permanent magnet 17, and the movable coil 13 is inserted into a cylindrical magnetic path gap formed between them. The magnetic flux generated therein traverses the moving coil 13. Therefore, when a drive current is applied to the moving coil 13, the moving coil and the magnetic flux electromagnetically cooperate to generate a displacement force on the moving coil 13 to the left in FIG. 3, which causes the printing hammer device to 6 is actuated so that its striking member 8 can collide with the protrusion 3 of the rotating drum 2 shown in the first figure. A buffer member 20 such as rubber is fixed to the front surface of the columnar part 19 of the center yoke 15.
When the printing hammer device 6 is in the rest position, the back surface of the holder 14 comes into contact with it, and the buffer member 20 cushions the impact when the printing hammer device 6 returns to the rest position. Also, in Figure 1,
A recording medium 21 is inserted between the rotating drum 2 and the striking member 8.
The ink ribbon 22 is passed through the recording medium 2.
1 is a print head 4 via a tractor (not shown), etc.
The object is sent in a direction perpendicular to the direction of movement, for example, upward in FIG.

Further, the rotation of the rotary drum 2 and the printing head 4 are carried out in synchronization with each other through a common reversible rotary motor MTR (see FIG. 5). In FIG. 1, the rotation transmission mechanism for the rotary drum 2 and the spacing device for the print head 4 are omitted, but when the print head 4 moves in the forward direction, that is, in the right direction, the rotary drum 2 moves clockwise. Rotate. That is, the projection 3 is continuously displaced from above to below with respect to the striking member 8. On the other hand, when the print head 4 moves in the backward direction, that is, to the left in FIG. 1, the rotary drum 2 rotates counterclockwise.

That is, the projection 3 is continuously displaced from below to above with respect to the striking member 8.

In FIG. 4, the intersection position of the protrusion 3 and the striking member 8, that is, the position where the dot is formed, moves as follows. That is, by the rotation of the rotating drum 2, the position of the protrusion 3 facing the striking member 8 can be changed in the row (vertical) direction of the matrix.
At the same time, the movement of the printing head 4 causes its striking member 8 to move in the matrix row (horizontal) against the protrusion 3.
The direction position can be changed in the direction. Then, while a certain projection 3 moves downward or upward in front of the striking member 8, the printing hammer device is selectively driven at an appropriate timing.

The moving coil 13, which is clearly shown in FIG. 3, is actuated via the drive control circuit of FIG.
In Fig. 5, a character buffer CB in which print data is stored, and a character buffer CB in which print data is stored.
address counter that specifies the output address of
CBA, a latch L that stores the output of the character buffer CB, a character generator CG that generates a dot matrix pattern signal corresponding to the print data written in the latch L, and an output column of the character generator CG. Column counter CGC that specifies and character generator CG
It is equipped with a shift register SR in which, for example, a 7-bit parallel column signal output from the shift register SR is written, and a hammer buffer HB in which the signal read out from this shift register SR is temporarily stored.
Each is controlled via the central processing unit according to the flowcharts of FIGS. 7A and 7B. The moving coil 13 of the print head 4 is connected to a driver DRV that operates in response to the output of the hammer buffer HB.
It is connected to the. Furthermore, a sensor SNS ₁ that generates a print timing signal Tp and sensors SNS ₂ and SNS ₃ that detect the position of the print head 4 are connected to the central processing unit CPU. Although the sensors SNS ₁ , SNS ₂ , and SNS ₃ are omitted in FIG. 1, they are installed to function as follows. That is, sensor SNS ₁
For example, the slit disc is provided on a shaft (not shown) in a transmission mechanism that transmits the rotation of the motor MTR to the shaft 1 of the rotary drum 2, and a light emitting element and a light receiving element (both (Not shown.)
It is composed of. Print timing signal Tp
In this example, seven consecutive pulses are generated as one cycle, and each pulse is generated in the order in which it is generated. In forward printing, the protrusions 3 are sequentially moved to the 1st, 2nd...7th column of the matrix in Fig. 4. When the protrusions 3 face the striking member 8 with their eyes, or when performing double printing, the protrusions 3 in the same figure are sequentially 7, 6...the striking member 8 in the first row.
When facing each other, each occurs synchronously. Sensors SNS ₂ and SNS ₃ are adapted to output when the print head 4 is located at the left end of the device.

In FIG. 5, in the initial state, the character buffer CB, its address counter CBA, the column counter CGC of the character generator CG, the hammer buffer HB and the counter CTR are cleared. Therefore, a description will be given in accordance with the flowcharts of FIGS. 7A and 7B, starting from the point where the print head 4 is currently located at the left end in FIG. 1 and executes forward printing.

Print data sent from electronic computers, etc.
As in the past, each time a strobe signal is output from the central processing unit CPU, it is stored in the character buffer CB one after another according to the flow shown in Figure 7A, and at the same time, the count value of the address counter CBA is incremented one by one. It will be done. When a print command signal arrives after one line of print data has been stored in the character buffer CB, it is determined whether the print head 4 is located at the left or right end.

Now, since the print head 4 is located at the left end, the sensor SNS ₂ is outputting. Upon receiving the output of Sansa SNS ₂ , the count value of address counter CBA is cleared to 0, and then motor MTR starts rotating in the forward direction. As a result, the print head 4 moves to the right in FIG. 1, and the rotary drum 2 rotates clockwise. The character buffer CB outputs print data at the address (at this point, address 0) corresponding to the count value of the address counter CBA, and this print data is stored in the latch L according to the flow shown in Figure 7B. be done. In the case of forward printing, use the character buffer address counter.
A comparison is made to see if the CBA count value has reached the maximum value, and if it has not reached the maximum value, the following operations proceed. i.e. address counter CBA
The count value of is added by 1, and the column counter
CGC is cleared and its count value becomes 0. The subsequent operation does not proceed while the output of sensor SNS ₂ is on. When the print head 4 travels a certain distance from the left end and reaches the printable area, the sensor SNS ₂ is turned off. The output of the character generator CG is then written to the shift register CGS. Here, the column counter CGC counts 0, and the character generator CG outputs the first column pattern signal corresponding to the print data stored in the latch L. When the write operation is completed, 1 is added to the count value of the column counter CGC, and the counter CTR is also cleared. Then, in response to the arrival of the print timing signal Tp (see Figure 6) from the sensor SNS ₁ , the pattern signals written in the shift register CGS are read out in the order of their memory addresses, and are sent via the hammer buffer HB and the driver DRV. A drive current is selectively applied to the movable coil 13 in accordance with the pattern signal. That is, while the protrusion 3 is moving from top to bottom against the striking member 8, which is moving to the right in FIG. Thus, dots in corresponding rows are selectively formed in order from the top. The counter CTR counts the pulses of the print timing signal Tp, and when the counter CTR counts 7 and the formation of one row of dots is completed, it is determined whether the column counter CGC has counted 5 or not.
Until the count value of the column counter CGC reaches 5, the above routine after the output of the character generator CG is written to the shift register CGS is repeated, and the dots in the 2nd to 5th columns of the print data are written as above. (see Figure 4).

When the printing of one print data is completed, that is, when the column counter CGC counts 5, the process returns to the subsequent routine where the print data of the character buffer CB is stored in the latch L, and in the same manner as above, the second The print data after the digit is printed sequentially. When printing of print data per line is completed and the count value of the address counter CBA reaches the maximum value (maximum number of digits for one line), routines after B in FIG. 7A are executed. That is, in FIG. 1, the motor MTR is stopped after the print head 4 reaches the right end and the sensor SNS ₃ is turned on.
Then, the recording medium 21 is fed by a certain amount. Thereafter, the busy state is released, the address counter CBA, etc. are all cleared, and the system returns to the initial state.

Subsequently, print data for the next print line is stored in the character buffer CB, and a print command signal arrives there. At this time, since the print head 4 is located at the right end and the sensor SNS ₂ is off, the count value of the address counter CBA is set to the maximum and the motor MTR is driven in the opposite direction to that for forward printing. Ru. As a result, the print head 4 moves to the left in FIG. 1, and the rotary drum 2 rotates counterclockwise. The character buffer CB outputs print data at the address (at this point, the final address) corresponding to the count value of the address counter CBA, and this print data is sent to the latch L.
is memorized. Then, during this double printing, a comparison is made to see if the count value of the address counter CBA of the character buffer is 0 or not, and if it is not 0, the following operations proceed. That is, the count value of the address counter CBA is now subtracted by 1, and the column counter CGC of the character generator is set to 5. Then, after the print head 4 travels a certain distance from the right end and reaches the printable area and the sensor SNS ₃ is turned off, the output of the character generator CG is written into the shift register CGS. At this point, the count value of the column counter CGC is 5, so the character generator CG is outputting a pattern signal for the fifth column corresponding to the print data stored in the latch L. When the write operation is completed, the count value of the column counter CGC is decremented by 1, and the counter CTR is cleared. Then, in response to the arrival of the print timing signal Tp (see Figure 6) from sensor SNS ₁ , the shift register
The pattern signals written in the CGS are read out in the reverse order of their memory addresses, and the hammer buffer is
Moving coil 13 via HB and driver DRV
A drive current is selectively applied to. That is, while the protrusion 3 is moving from bottom to top against the striking member 8, which is moving leftward in FIG. 4, the striking member 8 selectively collides with the striking member 8 at an appropriate row position. Thus, the dots in the corresponding columns are selectively formed in order from the bottom, that is, in the reverse order of the rows. When the counter CTR counts 7 and the formation of one row of dots is completed, the count value of the column counter CGC becomes 0.
It will be judged whether or not it has become. column counter
The above routine after the output of the character generator CG is written to the shift register CGS is repeated until the count value of CGC becomes 0.
The dots in the fourth to first columns of the print data are selectively formed in the same manner as above.

When printing of one piece of print data is completed and the column counter CGC counts 0, the process returns to the subsequent routine where the print data of the character buffer CB is stored in the latch L, and the print data is printed one after another in the same manner as above. Print data is printed in the reverse order of the digit number. When printing of the print data per line is completed and the count value of the address counter CBA becomes 0, the subsequent routine shown in FIG. 7A is executed. That is, in FIG. 1, the motor MTR is stopped after the print head 4 reaches the left end and the sensor SNS ₂ is turned off, and then the recording medium 21 is turned off.
A certain amount is sent, then the busy state is released,
Also, the address counter CBA etc. are cleared and returned to the initial state. Then, reciprocating printing to the left and right is repeated in the same manner as above.

In the above embodiment, the motor MTR may be continuously driven in a fixed direction, and the movement of the print head 4 and the rotation of the rotary drum 2 may be switched through an appropriate clutch device.

According to the printing method of the present invention described in detail above, in forward printing, dot groups constituting characters, etc. are formed in order from the first column, and in each column, dot groups are formed in order from the first row. In addition, when performing double printing, the dots that make up the characters, etc. are formed in the reverse order starting from the last column, and in each column, the dots are formed in the reverse order starting from the last row. This is a novel and distinctive point that is significantly different from reciprocating printing using, for example, wire printers. By using this printing method, it is possible to easily perform reciprocating printing even with a dot printer having a special configuration such as that of this embodiment.

[Brief explanation of the drawing]

Fig. 1 is a perspective view schematically showing the main parts of a printer to which the printing method of the present invention is applied, Fig. 2 is an enlarged front view of the printing head, Fig. 3 is a sectional view taken along the line of Fig. 2, and Fig. 4. 5 is a block diagram showing an example of a control circuit for the printing method of the present invention, FIG. 6 is a waveform diagram of a printing timing signal, and FIG. Figure 7A and 7th
Each figure B is a flowchart. 2... Rotating drum, 3... Protrusion, 4... Printing head, 6... Printing hammer device, 8... Hitting member,
13, 15, 16, 17...electromagnetic drive device, θ
...The inclination angle of the striking member 8.

Claims (1)

[Scope of Claims] 1. A print head having a plurality of protrusions extending in the axial direction formed on the outer circumferential surface of a rotating drum and equipped with an electromagnetically driven print hammer device drives the recording medium in front of the rotating drum. The printing hammer device is provided to move in a direction perpendicular to the feeding direction of the recording medium, and the printing hammer device is tilted at a certain angle to the right with respect to the feeding direction of the recording medium. In a dot printer comprising a striking member intersectingly facing the protrusion, the dot matrix character or the like is formed on the recording medium by collision between the protrusion and the striking member; When moving in the direction, the rotary drum is rotationally driven so that the protrusion is displaced downward with respect to the striking member; in this case, forward printing is performed by printing a group of dots constituting the character, etc. in the first row. and from the first row in each column; when the printing head moves in the backward direction, the rotating drum is moved such that the projection is displaced upward with respect to the striking member. Rotationally driven; The double printing at this time is characterized by forming the dot groups constituting the above-mentioned characters etc. in the reverse order from the last column, and in each column in the reverse order from the last row. Dot printer printing method.