JPS581679B2 - printing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a printing device that allows uniform contact between a print head and printing paper and provides extremely good print quality.

Still other objects of the present invention will become clear from the description of the embodiments that will be described below.

An embodiment of the present invention will be described in detail below with reference to the drawings.

Figures 1 to 5 show the drive mechanism in one embodiment of the present invention, and 1 indicates operations such as advancing and reversing the print head, advancing one line of print paper as a recording medium, and changing the print posture of the head. In this embodiment, a reversible step motor (Pulsmoke) is used as a driving means for performing the above operations using a single driving source.

The stator side of the step motor 1 is fixed to the middle plate 2, and its rotating shaft 3 is engaged with a gear 6 of a winding shaft 5.

The winding shaft 5 is rotatably supported by a shaft 42 on the left side plate 4, and is driven to rotate intermittently by the rotating shaft 3.

Further, a wire 8 whose starting end and ending end are fixed is freely wound and unwound around the winding shaft 5, and by winding and unwinding the wire 8, the intermittent rotational movement of the step motor 1 is made intermittently. Convert to linear motion.

A carriage (head holder) 10 on which a print head 9 is mounted is attached to a wire 8 that makes intermittent linear motion.

The attachment portion 11 of the wire 8 and the carriage 10 is held by various means such as screws, bent protrusions, and eyelets.

The wire 8 whose starting and ending ends are fixed to the winding shaft 5 has an endless configuration, and a carriage 10 held at an appropriate position in the middle moves intermittently to print on the printing paper.

Further, the wire 8 is suspended so as to be able to run by rollers 12, 13, 14, 15, etc. so as to surround the periphery of the printer main body, thereby making the entire printer compact.

The carriage 10 is held on a carriage support shaft 17 at an angle appropriate for printing, and is held slidably in the axial direction in order to maintain the printing posture of the print head 9 and printing paper 16.

In this embodiment, a sliding member 20 made of plastic or the like is provided inside the carriage in order to provide sliding properties between the support shaft 17 and the carriage 10.

The support shaft 17 is rotatably supported at axial points 181 and 19 between the right side plate 21 and the middle side plate 2 of the main body, and one end of the dogleg-shaped lever 22 is set at the axial point 18 of the support shaft 17. A rotational force is applied to the support shaft 17 toward the print paper by a spring 25 pulling the support shaft 24, and the carriage 10 and print head 9 supported by the tag shaft 17 are pressed against the print paper 16 and the pad 58.

The other end of the spring 25 is fixed to a support rod 26 for supporting the middle side plate 2 and the side plate 4.

The left side plate 4 has a support shaft 42 for the winding shaft 5 and rollers 12,1.
3, etc. are rotatably supported, and as described later, a switch 27 for detecting the end of reverse movement of the head 9, a support shaft 39 of the paper feed lever 30, and a stopper bin 4 of the lever 30.
0 and 41 etc. are provided.

One end 33 of the paper feed lever 30 is rotatably supported by a support shaft 39 fixed to the left side plate 4, and is biased downward by a coil spring 38 wound around the shaft 39 and stopped by a stopper pin 40. ing.

Also, the other end 3 of this lever 30 is on the same plane as the one end 33.
A paper feed claw 46 is rotatably supported on the shaft 31 at 2.

The protrusion position detection member 34 of the winding shaft 5, which is integrated with the paper feed lever 30 and bent perpendicularly to the surface of the lever 30, is connected to the winding shaft 5.
The contact pieces 28 and 29 of the tag switch 27 are pushed upward by the protrusion 7 provided on the holder 7, and the contact pieces 28 and 29 of the switch 27 are brought into contact with each other just before reaching the stopper pin 4F. The control unit 70 in FIG. 10 is notified.

The protrusion position detection member 34 is provided with buffer members 35 and 36 for eliminating impact noise with the stoppers 40 and 41, and a push-up member 37 made of an insulating material for bringing the contact pieces 28 and 29 of the switch into contact with each other. .

A paper feed claw 46 rotatably supported by the paper feed lever 30 is pressed by a spring 45 to claws 49, 50 of a ratchet wheel 48, etc.

The ratchet wheel 48 is fixed to the rotating shaft 51 of the paper feed roller 53.
Each nail advances one line of printed paper.

The printed paper 16 is held between a paper feed roller 53 and a pressure roller 54.

The pressure roller 54 is a part 62 of the guide member 60 for the printing paper 16.
Supported by

The member 62 has a notch made in the middle of the member 60 near 61, and the natural elastic force of the member 60 presses the roller 53 to obtain a uniform pressure.

An opposing platen (butt) 58 of the print head 9 is made of a highly elastic material such as rubber, and is supported by a support plate 55 .

Reference numeral 59 denotes an intervening member, and in this embodiment, it is made of a heat-resistant thin film with a low coefficient of friction, such as registered trademark Teflon (polytetrafluoroethylene), and is fixed to one end 5T of the support plate 55. The batt 58 is coated in a loose state without being bonded, and after being stretched with an appropriate tension near the other end 56, it is fixed with an adhesive tape or the like.

In conventional bats, the film 59 was attached directly to the pad 58, which caused wrinkles, distortions, etc. on the surface of the film due to expansion and contraction due to changes in room temperature and humidity, frictional heat due to movement of the print head, and expansion and contraction due to mechanical displacement. Uniform contact between the head and the printing paper could not be maintained.

Further, when inserting the printed paper, the horizontal end surface of the printed paper sometimes collides with the vat, causing inconvenience in loading.

However, according to the printing device according to the present invention, as described above, the pad 58 and the book membrane 59 are in a loose state and are only lightly contacted, but are not bonded together, and the printing paper is guided near the support plate 55, so the above-mentioned drawbacks are avoided. This could be completely resolved.

A thermal head that prints by selectively energizing dot elements or segment elements to generate heat and causing a chemical change in thermal paper is suitable for the print head of a printing device having a bat as described above.

FIG. 6 shows an example of a thermal head.

Reference numeral 65 denotes a semiconductor substrate such as silicon, on which a predetermined number of heating elements 66 with built-in resistors are formed, and when electricity is applied, selected elements generate heat to print letters, numbers, etc. on electric shock paper. .

64 is a semi-rack holding silicon 65 to diffuse the heat of the heat generating element 66, and a heat sink 9 made of aluminum or the like dissipates the heat.

Reference numeral 67 denotes a flexible wiring material that forms an energizing path for selectively energizing the heating element 66.

This energizing path 67 is inputted from a printing section 69 to a control section 70 and connected to a character generator 82, as shown in FIG.

The step motor 1 has a four-phase configuration and performs one rotation intermittently with four pulses.

Sequential pulses ■0, ■1, ■2 from the drive pulse generator 71
,■3 occurs, the rotor of motor 1 changes from A3L to A
0L, A0L → A1L, A1L → A2L, A2L → A3
It rotates intermittently every 90 degrees in the order of the L coil position.

With this intermittent rotation of 90 degrees, the wire 8 is wound around the winding shaft 5 by one character to be printed, and the carriage 10 is sent in the direction of the printing line by one character to print.

Conversely, when pulses occur in the order of ■3, ■2, ■1, and ■0, the rotor of motor 1 changes from A0L to A3L, A3L, A
3L→A2L, A2L,→A1L, A1L→A0L, and the carriage 10 returns to its original position.

Further, the low speed of the motor 1 is set so that when the carriage 10 is stopped at the printing start position, it remains at rest at the position of the coil 0A0L.

An embodiment of the drive control means for driving the motor 1 is shown in FIGS. 11 and 12.

In the figure, 83 is an inverter that inverts the print head return command (carriage return cR) signal from the calculation unit or calculation control unit of the computer, and 84 is the calculation result calculation command signal from the external control device of the computer, such as the keyboard. K
The NAND logic gate 85 to which F, an output signal 0 of a NAND gate 99 (described later), and a set output SIG of a flip-flop 96 (described later) are applied, also receives a print paper feed command (paper feed) signal PFE from the keyboard and a set output SIG of the flip-flop 96. 86 is a NAND logic gate to which the above NAND logic gates 83 and 84 are applied.
, 85 is a NAND logic gate.

A NAND logic gate is a gate whose output becomes high level when at least one of its inputs is low level in positive logic.

(The following explanations are all based on positive logic) 87 is a flip-flop, and the NAND logic gates 83, 84, 85 and 8
6 and is set in synchronization with the fall of the clock pulse CP to generate a reverse signal BACK for rotating the step motor 1 in reverse and moving the carriage 10 backward.

Further, it is always in a reset state, and the reset output terminal generates a step signal FORW for causing the step motor 1 to rotate in the forward direction and moving the carriage 10 forward.

A NAND logic gate 88 is a gate for synchronizing the BACK signal with the next clock signal, and a NAND logic gate 89 is a gate for outputting the FORW signal to a subsequent stage in response to a print command signal PRINT or the like.

90 is a NAND logic gate that receives the outputs of the NAND logic gates 88 and 89;

Reference numeral 91 denotes a flip-flop which is inverted when the output of the NAND logic gate 90 falls and constitutes the first stage of the quaternary counter, and is normally reset.

Numerals 92 and 93 are NAND logic gates which are opened and closed by the set signal T1, reset signal T1, FORW and BACK signals of the flip-flop 91 as described above, and 94 is a NAND logic gate which receives the outputs of the NAND logic gates 92 and 93.

95 receives the output of the gate 94 at the set and reset input terminals, and is inverted in synchronization with the fall of the output of the gate 90 and the fall of the output of the NAND logic gate 94 at the same time, and constitutes the latter stage of the quaternary counter. It is a flip-flop that always resets.

96 is set and reset input terminals FORW and BA, respectively.
CK signal is input and set output T2 of flip-flop 95
It is a flip-flop that is inverted in synchronization with the falling edge of , and is always reset.

When the set output SIG of the flip-flop 96 is being generated, the print head is in the process of printing on the print paper, and information from the character generator 82 is given to the print head 9 through the lead wire 67, allowing it to print. It has become.

Furthermore, when the reset output SIG signal is being generated, the head 9 is in a state in which it is moving backwards due to the clock pulse CP, and in a state in which the head is in a state in which it is returning in steps from the head return end position to the printing start position, and during this time, printing is not performed. is not carried out.

NAND logic gate 97 receives the SIG and T2 signals and the output of gate 94 and applies its NAND logic output to the input terminal of flip-flop 98.

Like the flip-flop 87, the reset output T3 of the flip-flop 98 is always kept at a high level, and its output is input to the NAND gate 99.

Reference numeral 99 represents a NAND logic gate for receiving reset outputs T1, T2, T3 of the flip-flops 91, 95, 98 and outputting a signal O.

100 is an inverter that inverts the print signal PRINT; 101 is a NAND logic gate to which the SIG signal and the CP signal are applied; and 102 is a NAND logic gate that receives the output of the inverter 100 and the output of the NAND logic gate 101.

103 is a calculation result calculation command key, 104 is a flip-flop which is set by a signal from the calculation result calculation command key and reset by a signal from a calculation control unit 106, which will be described later. This is an AND logic gate that receives an inverted signal O of the output signal O.

An AND logic gate is a gate whose output is at a high level when all of its inputs are at a high level.

Reference numeral 106 designates an arithmetic control unit for controlling the arithmetic operation of the arithmetic unit, 107 a function key, 108 a one-shot multi-by-break, and 109 an OR logic gate.

An OR logic gate is a gate whose output is high when at least one of its inputs is high.

110 is a one-shot multivibrator.

Numerical keys 111 generate a numerical signal N.

The drive control circuit having the above configuration is a practical circuit configuration that is convenient for use when embodied as a chip such as an IC or LSI.

However, for the sake of simplicity, the following operation will be explained using the circuit shown in FIG. 13, which is a simplified version of the circuit configuration shown in FIG. 11.

FIG. 13 shows a circuit configuration completely equivalent to FIG. 11.

In other words, de Morgan's law
FIG. 13 shows a modification of the circuit configuration of FIG. 11 using Law) a×b=a+b.

In this case, it goes without saying that some changes will be required in FIG. 12, and the inverters 83 and 100 will be unnecessary.

Components in FIG. 13 that are the same as those in FIG. 11 are designated by the same reference numerals.

112, 113, 115, 116, 118, 119 and 112 are ungates, 114, 117, 120, 121
and 123 is an or gate.

FIG. 14 shows the input/output signal waveforms of each element in FIG. 13 (FIG. 11) and FIG. 12.

Next, the specific operation of the printing apparatus of the present invention having the above-mentioned configuration will be explained below using the numerical value 123.456+ as an example.

As shown in FIG. 9, it is assumed that the print head 9 on the carriage 10 is stationary at a print start position A0 on the print paper 16.

Here, press the number key (NK) 111 on the keyboard to enter the number 1.
When input, the numerical information is stored in a storage device such as a register in the character generator 82 in FIG.

Also, this key signal is transmitted to the arithmetic control section 1 as shown in FIG.
06 generates a PRINT signal, and the print head 9 prints at the print start position A0 "1".

On the other hand, the PRINT signal opens OR gate 123 and is applied to AND gate 116.

At this time, the flip-flop 87 is reset by the END signal from the switch 27 being applied to the clear input terminal in the state before the printing device, and the high level signal of FORW is being applied to the AND gate 116.

Therefore, AND gate 116 is opened, OR gate 117 is opened, and a high level signal is applied to flip-flops 91 and 95.

However, since the flip-flops 91 and 95 are flip-flops that are inverted in synchronization with the falling edge of the signal, their states do not change and remain reset.

Next, when the PRINT signal becomes low level, OR gate 1
23 is closed, and therefore the AND gate 116 is also closed, and since the AND gate 115 cannot be opened, the OR gate 11 is closed.
7 is also closed, and a low level signal is applied to flip-flops 91 and 95.

Therefore, the flip-flop 91 is inverted and a set output T1 signal is output.

Therefore, AND gate 118 is opened, OR gate 120 is also opened, and a high level signal is applied to another input terminal of flip-flop 95.

At this time, since the input signals to the flip-flop 95 do not match the synchronization, the flip-flop 95 does not invert its state.

Therefore, the content of the counter at the time of the first fall of the PRINT signal is 1 when T1 and T2 are at high level, and when this is input to the sequential pulse generator 11 shown in FIG. Pulse (1) is applied to the coil A1L to excite it.

Therefore, the rotor (not shown) which was stationary at the position of coil A0L rotates 900 times and comes to rest at position A1L.

When the shaft 3 of the step motor 1 rotates 90 degrees, the winding shaft 5 shown in FIG. 1 rotates by a certain angle and winds the wire 8 by one character length.

As a result, the print head 9 on the carriage 10 loaded on the wire 8 moves from the print start position A0 to the next print position A1.
Move one order of magnitude in the direction of the lateral force.

Next, when the number 2 is input from the number key 111, “2”
is printed, the OR gate 123 opens, and accordingly the AND gate 116 opens, and therefore the OR gate 117 opens and a high level signal is applied to the flip-flops 91 and 95.

At this time, the flip-flop is not inverted and T1, T2
remains at a high level.

Next, when the PRINT signal becomes low level, OR gate 123 is closed, AND gate 116 is closed, and therefore OR gate 117 is opened and a low level signal is applied to flip-flops 91 and 92.

Therefore, the flip-flop 91 is inverted and the reset output T
1 signal appears.

At this time, since the BACK signal is not applied, AND gate 119 does not open, and AND gate 118 cannot open, so OR gate 120 also does not open.

Therefore, the low level signal and the above low level signal are applied to the flip-flop 95, that is, the input signals fall at the same time, so the flip-flop 95 is inverted and the set output T2 signal is output.

Therefore, the contents of the counter T1 and T2 become high level, the counter counts 2, and the AND gate 74 generates a pulse 2.

Pulse 2 advances the step motor further 90 degrees, and 3
Move to the digit printing position A2.

Furthermore, when the numerical value 3 is inputted from the keyboard, printing occurs at the high level of the step PRINT signal similar to the above, and 3 occurs at the low level, and the carriage 10 is fed by intermittent rotation of the step motor.

Thereafter, printing and head feeding are performed in order up to the number 6 in the same manner.

Next, when the + key of the function key (PK) 107 is pressed, the signal is input to the arithmetic control unit 106 in the same way as the numerical value, and a + sign is printed.

Also, this key signal is one shot multi-bye break O
One-shot multi-OS is delayed for a predetermined time in S1
Start 2.

The output of OS2 becomes the carriage return signal CR shown in FIG. 14, and the set side input terminal of flip-flop 87 becomes high level.

The flip-flop 87 whose set side input terminal is at high level receives the clock pulse CP applied to its synchronization input terminal.
It is set in synchronization with the falling edge of , and is applied to the BACK signal and the AND gate 115.

At the same time, the reset output FORW signal is at a low level, and the reand gate 116 is closed.

AND gate 115 inputs clock pulse CP to flip-flop 91 via OR gate 117.

Also, AND gate 118 is closed and gate 119 is opened.

Therefore, when the print head returns, the counter counts the falling edge of the clock pulse in a subtractive manner, and when this is decoded, pulses in the order of ■3 → ■2 → ■1 → ■0 are generated from 71, and the step motor 1 is reversely rotated. It will start rotating intermittently.

Since the clock pulse CP has a much higher frequency than the PRINT signal, the wire 8 is moved almost effortlessly at high speed to the winding shaft 5.
The carriage 10 is rewound and quickly moves backward.

Here, the carriage 10 passes the initial printing start position A0 and further moves backward to the final position where the stitch 27 is closed.

When the carriage 10 is stationary at the printing start position, the protrusion 7 of the winding shaft 5 and the protrusion position detection member 34 are at the position shown by the solid line in FIG.

That is, the protrusion 7 of the winding shaft 5 is on the boundary line of the rotation range AB.

Further, since one end 23 of the head printing attitude changing lever 22 is open and the other end 24 is tensioned by a spring 25, the head 9 on the carriage 10 presses the bat 58 through the printing paper 16.

Further, the detection member 34 is biased downward by a coil spring 38 and further stopped by a stopper pin 40, and is located at the lowest end so that a bent portion 47 of a paper feed pawl 46 engages with a pawl 49 of a ratchet wheel 48.

Here, the print head 9 is energized with numerical information as described above,
After one character is printed, the axis 3 of step motor 1 becomes 90.
° The winding shaft 5 rotates to the right and the winding shaft 5 rotates to the left by a certain angle to wind a certain amount of wire 8. Therefore, the print head 9 on the carriage 10 is
Move one digit to the right.

In this way, as the step motor 1 rotates intermittently to the right, the winding shaft 5 rotates intermittently to the left to advance the head, and when the position of the protrusion 7 rotates to the maximum angle in the range B, the maximum number of digits can be printed. has been done.

When the print head 9 is being fed in the printing direction, the movable parts are extremely simply composed of only the winding shaft 5, the wire 8, and the carriage 10, as described above.

Next, a carriage return signal CR is generated by the function signal + from the function key 107, and when the contents of the counter are counted in the subtraction direction, the shaft of the step motor 1 starts to rotate counterclockwise, contrary to the above. Reverse movement is performed.

For this operation, it is sufficient to simply rotate the sputter motor 1 in the reverse direction and completely reverse the printing case.

That is, even when the carriage 10 moves backward, the tension of the spring 25 is applied to the other end 24 of the lever 22, so that the pressing force to the pad 58 continues to be applied as in the case of printing.

With this configuration, an automatic head cleaning effect can be expected in the case of a thermal printer in which the print head 9 on the carriage 10 is a thermal head and the print paper 16 is thermal paper.

In other words, in a mechanism in which the thermal head 9 prints while pressing thermal paper at high temperatures, it is inevitable that paper fibers, combustion waste, physicochemical deposits, etc. will adhere to the head during printing. Traditional thermal printers sometimes require the operator to clean the head using specialized cleaning means.

In order to overcome the above-mentioned drawbacks, the printing device of the present invention is configured to wipe and remove impurities adhering to the head during printing by using the pressure applied to the bat when the head returns. .

When the printing head is returned while being pressed in this manner and moved backward to the printing start position A0, the state before printing returns and the protrusion 7 of the winding shaft 5 returns to the position indicated by the solid line in FIG. 2.

The counter now counts several more clock pulses,
Continue moving the carriage 10 backwards.

In this embodiment, the positional relationship of the heads is set so that, for example, four clocks are counted after reaching A0.

That is, while the print head 9 moves backward to the position A0 as shown in FIG. 9, the protrusion 7 of the winding shaft 5 rotates clockwise within the range A in FIG. 2.

The protrusion position detection member 34 engaged with the protrusion 7 is gradually pushed upward until the buffer member 36 provided on the member 34 hits the stopper pin 41.

Further, the contact piece push-up member 37 provided on the member 34 closes the contact pieces 28 and 29 of the switch, and notifies the control section 70 through the lead wire 44 that the head 9 has reached the terminal position.

This signal is used as an END signal to reset the flip-flops 87, 96 and 98 in the drive control means and
Generate W, SIG, and T3 signals to switch the count.

During the same period, when the protrusion 7 brings the detection member 34 to a substantially horizontal position, the horizontal upper surface of the member 34 comes into contact with the one end 23 of the head attitude change lever 22, and the spring 25
One end 23 is pushed up against the tension of.

Since the lever 22 is fixed to one end 1B of the support shaft 17, the shaft 17 rotates clockwise as the lever 22 rotates.

The carriage 10 is attached to the shaft 17 by the sliding member 20 as described above.
Since the print head 9 and the print head 9 are slidably supported, the shaft 1
7, the print head 9 is released from the print paper 16, and when the detection member 34 is stopped by the stopper pin 41, the print head 9 is released to the maximum extent.

Furthermore, during this same period, the member 34 is integrated with the detection member 34.
The paper feed lever 30 is bent and formed perpendicularly to the horizontal plane of the paper feed lever 30.
is also pushed up together with the member 34 by the rotation of the protrusion 7.

This pushing up force is sufficient to resist the downward urging force of the lever 30 by the coil spring 38.

The bent portion 47 of the paper feed pawl 46, which is rotatably supported and suspended on the fulcrum 31 of the one end 32 of the paper feed lever 30, is lifted by the left rotational force of the lever 30, and the pawl 49 of the ratchet wheel 48 is lifted.
is engaged to rotate the ratchet wheel 48 to the left.

Therefore, the shaft 51 that is integrated with the ratchet wheel 48 also rotates to the left.
The paper feed roller 53 connected to the shaft 51 rotates, and the shaft 5
The paper feed roller 53 connected to 1 rotates to gradually feed the paper.

As described above, when the member 34 hits the stopper pin 41, the paper is fed to the maximum height and then stopped.

At this time, just before the member 34 reaches the pin 41, the switch 27 is closed by the push-up member 37, and the counter in the drive control means is FORW which incrementally calculates the clock pulse CP.
set on the side.

That is, the reset output signal SI of the flip-flop 96
AND gate 122 by G and clock pulse CP
is open, the OR gate 123 is also open, and is therefore already applied to the AND gate 116.

The AND gate 116 is opened by the FORW signal and the output signal of the OR gate 123, and the counter is PRIN.
Start counting incrementally in the same way as the T signal.

Therefore, the step motor 1 again starts to rotate intermittently to the right, the winding shaft 5 also rotates to the left again, and the projection 7 starts to descend from the maximum point of the range A.

When the protrusion 7 begins to descend, the member 34 is tilted downward by the coil spring 38 and stopped by the stopper pin 40, returning to the initial state.

The paper feed pawl 46 of the paper feed lever 30 also moves downward, and the bent portion 47 of the pawl 46 slides along the longitudinal slope of the pawl 50 due to the force of the spring 45, and finally comes to rest on the bent portion 47 to feed the next paper. Make settings.

The lever 22 is also returned to its original state by the spring 25, and the print head 9 is pressed onto the butt 58 via the print paper 16.

The number of stepping pulses for the head 9 to reach the print start position A0 is four, which is the same number as the number of pulses from the A0 position to the -A0 position.

This is because the counter in the drive control circuit counts exactly four clock pulses and then stops.

As is clear from the waveform diagram in FIG. 14, during the high level time of the SIG signal, the flip-flop 87 is set and the BA
The first flip-flop 95 after the CK signal is generated
It is sufficient to define the period from the time when the set output T2 falls to the first fall of T2 after the reset output FORW signal of the flip-flop 87 is generated by the END signal of the switch 27.

With this configuration, exactly four clock pulses CP
The counter counts and further stores this value, thereby making it possible to stop the print head 9 at the print start position A0.

In this manner, the printing apparatus of the present invention is capable of stopping the print head 9 at the printing start position extremely accurately.

The printing head is not limited to the thermal head as described above, but many other types such as discharge printing needle heads, wire matrix heads, ball type heads, electric field printing heads, inkjet type heads, etc. can be used.

Also, the structure of the print head (e.g. thermal head)
If the notch 68 is provided as shown in the figure, the printing attitude changing mechanism of the head can be omitted from the embodiments shown in FIGS. 1 to 5.

Further, in the printing apparatus of the present invention, since the print head 9 moves to a position away from the print start position, it is possible to provide special means for cleaning the print head, heat dissipation promoting means, etc., an example of which is shown in FIG.

If the print head 9 is a thermal head having a heat generating part 66, a means for cleaning the heat generating part 66 (for example, silicone oil,
If a felt containing monoethyl diphenyl, diethyl diphenyl, etc.) is provided on the middle side plate 2, the print head 9
A cleaning effect can be expected.

That is, when the print head 9 moves backward to the left from the printing start position and further moves to a position where it leaves the print paper 16, the heat generating part 66 of the head 9 comes into contact with the cleaning means 52, and the contact engagement with this cleaning means 52 occurs. The heat generating part 66 is cleaned by further advancing the reverse movement while cleaning the heat generating part 66.

This cleaning means is particularly effective when the heat generating section 66 is easily dirty, such as in a thermal head.

Furthermore, the present invention is most suitable for print heads that are heavily soiled, such as other electric field print heads and inkjet heads.

In this case, cleaning means suitable for each print head may be provided on the middle plate 2, and the cleaning action may be performed when the printed portion 66 comes outside the printing paper.

In the case of the example shown in FIG. 8, the print head having the cut arrow part 68 shown in FIG.
can be brought to

Therefore, it is convenient that the pressure force of the print head 9 on the print paper 16 can be used as is.

In this case, as described above, the paper is fed using the gap in the cut arrow portion 68.

However, in the case of the example shown in FIG. 1, the printing posture of the head is changed and the paper is fed, so in this case, the cleaning means may be provided at a location depending on the posture of the head.

Further, if the printing head 9 is brought into light contact with the cleaning means 52 intermittently by utilizing this reciprocating movement to change the posture position, a remarkable cleaning effect can be expected depending on the type of head.

Furthermore, for a head such as a thermal head whose printing portion is at a high temperature, a cooling effect can be expected from this cleaning means, and heat dissipation by conduction is promoted.

Furthermore, if heat dissipation promoting means made of a good thermal conductor such as aluminum is provided in 52, in the case of a thermal head, the heat dissipation effect is further promoted, and the durability and lifespan can be favorably affected.

In addition, when it is necessary to feed paper continuously in the printing apparatus of the present invention, if the paper feed key (not shown) is held down, the AND gate 113 will open and close intermittently intermittently, allowing the desired number of lines to be fed. You can feed the paper in minutes.

In other words, one line of paper is fed while the head 9 moves backward from the print start position A0 to -A0, so if you AND the PFE signal from the paper feed key and the SIG signal, you will get the same operation as the CR signal. The paper is fed one line.

If you continue to hold down the paper feed key, this cycle repeats and you can send as many lines as you want.

This is simpler than the conventional mechanical paper feeding mechanism, and is another feature of the printing apparatus of the present invention.

Furthermore, another feature of the printing device of the present invention is that in the printing format on the printing paper 16, only the equal sign = is always printed at the leftmost print opening position A0, so that a very favorable effect can be obtained in terms of arrangement. .

That is, when the calculation result calculation command key 103 in FIG. 12 is pressed, the flip-flop 104 is set and the AND gate 112 (NAND gate 84) and the AND gate
A computation result calculation command signal 1KF is applied to 5.

Here, the print head 9 is at the print start position A.

When the printer is present at a location other than that, that is, during the incremental printing process, both the SIG signal and the output signal O of the AND gate 121 are at a high level.

Accordingly, the AND gate 112 opens and the counter switches to subtraction to bring the head to the print start position as described above, moves backward, and then switches forward and stops at the print start position A0.

When the print head 9 stops at the print start position A0 in this way, the flip-flop 104 is still set, and the output signal b of the OR gate 121 becomes low level, and conversely, the signal 0 becomes high level. The AND gate 105 opens and the set output 1KF signal of the flip-flop 104 is input to the arithmetic control section 106.

Therefore, in the same way as the numerical key action key signal, a calculation result display symbol, for example, an equal sign 1, is printed at the print start position A0, and further calculation results, etc. are printed successively.

The arithmetic control unit 106 also generates an effective print digit number in a register (not shown) or a register word length end detection signal, and applies it to an OR gate 109 to activate a one-shot multi 110 and generate a carriage return signal CR. to occur.

At the same time, the sense signal resets flip-flop 104.

Therefore, the print head 9 is again brought to the print start position A0 and stopped to prepare for the next print.

As mentioned above, on the printing paper 16, as shown in Fig. 9, ordinary arithmetic symbols ×, ÷, +, -, etc. are printed in the next digit of the numbering process, and the arithmetic result display symbol, for example, the equal sign 1, always starts printing. Since it is configured so that the result number is printed at the position and the result number is printed after the next digit, it is possible to obtain a printing format that is extremely easy to read.

In this way, the printing device of the present invention has a simple configuration, and many effects have been found by moving the print head further than the printing start position of the printing paper, and also by detecting the end position of the print head that has moved further. Since the drive control means is energized and the print head is driven to the print start position A0 with a small drive signal, the print start position of the head can be ensured extremely accurately, eliminating the drawback that the print start position is uneven. It was possible to do so.

Further, in this case, it is only necessary to move the print head 9 at least to a position where it deviates from the printing start position, and it is not necessarily necessary to move the print head 9 until it deviates from the printing paper 16.

As described in detail above, according to the present invention, it is possible to obtain a high-speed printing device that can perform all the main operations necessary for printing using a single driving means, and satisfies the demands for miniaturization and weight reduction. It's something you get.

Furthermore, it has many advantages such as extremely accurate setting of the printing start position, simplification of the drive control circuit, cleaning of the print head, and promotion of heat dissipation, and is of extremely high practical value.

[Brief explanation of drawings]

FIG. 1 is a diagram of one embodiment of the printing device according to the present invention, FIG. 2 is a cross-sectional view taken along line A-A' of the device No. 1P, and FIG.
B' sectional view, FIG. 4 is a diagram showing the paper feeding section of the device shown in FIG. 1, FIG. 5 is a sectional view of the print head shown in FIG. 4 being crimped, and FIG. A diagram showing a thermal head as an example of the print head, FIG. 7 is another embodiment of the print head, FIG. 8 is a still another embodiment of the present invention using the print head of FIG. 7, and FIG. 9 is a diagram showing the present invention. A diagram showing the movement principle of the print head in the printing device according to the invention, FIG. 10 is a diagram showing the combination of the printing section and the control section of the printing device of the invention, and FIG. 11 shows the main part of the control section in FIG. 12 shows another part of the control section in FIG. 10, and FIG. 13 shows a circuit equivalent to FIG. 11. A diagram for explaining the operation of the counter component, FIG. 14 is similar to FIG. 11 (FIG. 13) and FIG. 12.
Waveform diagrams are shown for explaining the operation of the circuits shown in the figures. In the drawings, 1... Reversible step mask, 8
...Wire, 9...Print head, 1
6...Print paper, 25...Spring,
27. ... Switch, 44 ... Lead wire, 52 ... Cleaning means or heat dissipation promotion means, 5
8...Elastic member, 59...Thin film, 71
... Drive pulse generator, 82 ... Character generator, 87, 91, 95, 96, 98, 104 ...
. . . flip-flop, 106 . . . arithmetic control unit.

Claims (1)

[Claims] 1. A printing device characterized by comprising a heat-resistant, low-friction-coefficient thin film interposed between a thermal head and a platen, fixed at its lower end, and coated in a loose state on the platen.