JPH1110971A - Printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing apparatus which can prevent a motor or gear from being broken or reduced in service life, by detecting locking of an automatic cutter because of a foreign article or the like early. SOLUTION: A CPU 58 outputs motor-driving signals Fn, Rn. A driver IC 59 turns voltages of wirings OUT1, OUT2 respectively to 'H', 'L', thereby driving and rotating a motor 37 forward. A detection switch 51 becomes off from on, and a voltage at a terminal (s) becomes 'H' from 'L'. A start of a rotation in an arrow B direction of a cam 46 is confirmed. A potential difference (V2-V1) indicates a normal value Va. When a moving blade is stopped by a foreign article, etc., and the motor 37 is locked, an internal resistance value of the motor 37 is reduced, a current is increased and the potential difference (V2-V1) at both ends of a resistor R1 of the wiring OUT1 becomes Ve larger than the normal value Va. As a result, the locking of the DC motor 37 is confirmed immediately. The CPU 58 inverts the output signals Fn, Rn, thereby rotating the motor 37 rearward.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing apparatus for automatically cutting a print-formed tape-shaped medium to be printed.

[0002]

2. Description of the Related Art Heretofore, small office equipment (or household stationery) commonly referred to as a tape printer or a label printer capable of easily printing and outputting on a tape-shaped print medium has been commercially available. In the use of this tape printer (hereinafter simply referred to as a printer), after printing a desired length on a tape-shaped printing medium, a printed portion of the tape-shaped printing medium is unprinted by a tape cutter. Used separately from

FIG. 7 shows an example of a tape cutter (automatic cutter) in such a case. The automatic cutter shown in the figure has a form of scissors with a fixed blade 91 and a movable blade 92. The movable blade 92 has a V
A V-shape is formed, and the lower part of the V-shape is rotatably supported by a fulcrum shaft 94. A long hole 95 is formed in the rotation arm 93 in the longitudinal direction.
7 is slidably fitted. When the cam 96 rotates in the counterclockwise direction, the pin 97 moves in a circular motion to raise the rotary arm 93 upward, thereby moving the movable blade 92.
Is rotated to the left to complete the shearing operation with the fixed blade 91.
Further, the cam 96 continues to rotate in the counterclockwise direction,
Moves circularly and returns to the original position while pulling down the rotating arm 93 downward. Thereby, the movable blade 92 is fully opened rightward. When the switch 99 detects the detection piece 98 of the rotating arm 93, the control unit recognizes that the movable blade 92 of the automatic cutter has returned to the reference position, and stops driving the cam 96.

[0004] When a foreign object (which cannot be cut by an automatic cutter) is caught, the control unit measures the non-detection piece detection period of the switch 99, and the period is longer than the normal tape cutting time. When the length of the motor becomes extremely long, the control unit determines that there is "foreign matter" and stops the motor, thereby preventing the intrusion of foreign matter and an excessive load on the motor and the gear train.

FIG. 8 is a time chart of the drive system when the control unit determines that "foreign substance is present" as described above. OUT-a and OUT-b in FIGS. 7A and 7B show wirings for supplying a current to the motor.
(c) shows ON / OFF of the switch 99, and (d) shows time (second). As shown in FIG. 8, the cutting operation start time T1 at which the current supply is started from the wiring OUT-a side in FIG.
As shown in (d), the time is set to 0 second, and a few hundred nanoseconds later, the switch 99 outputs a signal "H" indicating that the detection piece is not detected, as shown in (c) of FIG. Normally, after the movable blade 92 shown in FIG.
To return to the initial position, the cam 96 continues to rotate as it is, and the rotating arm 93 becomes horizontal two seconds after the start of timing, and the switch 99 detects the detection piece 98 and outputs a signal “L”. . However, as shown in FIG. 8, if it is assumed that a foreign object is caught in the automatic cutter and the motor is locked at the time T2 approximately 1.5 seconds after the start of the time measurement, the switch is not operated even if two seconds have elapsed since the start of the time measurement. The signal 99 remains “H”. The control unit monitors the period during which the signal “H” continues, for example, up to four seconds after the start of timing, stops the motor, and at the same time, inverts the outputs of OUT-a and OUT-b to reverse the motor. The movable blade 92 is pulled back to the initial position.

[0006]

By the way, the above-mentioned automatic cutter has a considerably large variation in the normal cutting time itself due to the transmission efficiency of the gear train and the variation in the cutting load of the automatic cutter. Therefore, when monitoring the lapse of time longer than the normal cutting time after the motor starts rotating to reversely rotate the motor from the middle when a foreign object is sandwiched as described above, there is considerable room for setting the monitoring period. It is necessary to set the time that was spent.

Therefore, when the automatic cutter is actually locked with a foreign object interposed therebetween, the time from the beginning until the motor starts reverse rotation is much longer than the normal cutting time. During this time, electric power is still supplied to the motor of the power source, so that a heavy load is applied to the motor and the gears of the drive transmission system. For this reason, there is a possibility that the service life is greatly shortened even if the motor or gear is damaged or not.

[0008] The object of the present invention is to solve the above-mentioned conventional situation,
It is an object of the present invention to provide a printing apparatus that detects the lock of an automatic cutter due to foreign matter or the like at an early stage and prevents damage to a motor or a gear or shortening of a service life.

[0009]

The construction of the printing apparatus according to the present invention will be described below. The printing apparatus according to the present invention includes a printing unit that prints on a print-receiving medium, a first cutting blade, an initial position having a predetermined relative positional relationship to the first cutting blade, and the printing in cooperation with the first cutting blade. A pair of cutter members comprising a second cutting blade movable between a shearing position in which the medium to be printed, which has been printed by the means, is completely sheared from the medium to be printed. A drive mechanism including a cutter power source for supplying power to perform a movement between the initial position and the shearing position, and a power transmission mechanism for transmitting the power of the cutter power source to the cutter member; and operation of the drive mechanism. Cutter control means for controlling the
Load detecting means for detecting the load of the power source during the movement of the cutting blade from the initial position to the shearing position; and returning the cutter member to the initial position based on the detection of overload by the load detecting means. And return control means for controlling the cutter control means.

[0010] Thus, the lock of the automatic cutter due to foreign matter or the like can be detected at an early stage, and the excessive load on the motor and the gear can be released at an early stage.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the printing medium is made of, for example, tape 16 ', the printing medium body is made of, for example, tape 16, and the printing means is made of, for example, thermal head 7, platen roller 8, stepping motor 35, and the like. The first cutting blade of the cutter member comprises, for example, a movable blade 12a, the second cutting blade comprises, for example, a fixed blade 12b, and the cutter power source of the driving mechanism comprises, for example, a DC motor 37, etc. The mechanism is, for example, a worm gear 38, a worm wheel 39,
Small diameter gear 40, reduction gear 41, spur gear 43, bevel gear 4
6, 44, a scissors cam 46, a pin 47, etc., the cutter control means comprises, for example, the control circuit of FIG. 1, the load detecting means comprises, for example, a detection switch 51, and the return control means comprises, for example, a CPU 58 and FIG. It is composed of the control algorithm shown.

FIG. 1 is a diagram showing a control circuit for controlling a tape cutting device (automatic cutter) of a printer (printing device) according to one embodiment, and FIG. 2A is a perspective view of the printer. FIG. 1A also shows, at the top, a tape cassette used by being attached to the printer.
FIG. 2B is a plan sectional view of the tape cassette. First, the overall configuration will be described with reference to FIGS. 2 (a) and 2 (b).

2 (a) and 2 (b), the printer 1 has a key input unit 3 below the upper surface of the housing 2, and the key input unit 3 has a cursor key, a format setting key, a print key, Cancel key, function key, print magnification key, upper / lower case selection key, shift key, single kanji key, conversion key, no conversion key,
A plurality of operation keys 4 including an execution key, a character input key for both kana input and alphanumeric input are provided.

A display unit 5 composed of a liquid crystal display device is provided on the upper left of the key input unit 3, and a tape cassette storage unit 6 is formed on the right side thereof. In FIG. 1, the tape cassette housing section 6 is shown without a cover member so that the inside can be seen. A thermal head 7 is disposed in the tape cassette storage section 6 so as to be rotatable up and down, and a platen roller 8 is disposed so as to be urged toward the thermal head 7 so as to face the thermal head 7. A tape reel support pin 9 and an ink ribbon take-up drive shaft 11 are provided below the thermal head 7, and a tape cutter 12 (movable blade 12a, fixed blade 12b) is provided on a side wall of the tape cassette housing section 6 on the right side of the thermal head 7. ) Are arranged. On the right side of the tape cutter 12 is a tape outlet 13
Are formed.

When the tape cassette 15 is accommodated in the tape cassette accommodating section 6, the tape reel support pins 9 engage with the tape reel holes 17 in the tape cassette 15 around which the tape 16 is wound. The ink ribbon take-up drive shaft 11 is engaged with the ink ribbon take-up reel hole 18 in the inside.

The tape cassette 15 is a cassette case 1.
The tape 16 is wound around the tape reel 21 inside the tape cartridge 0, and the ink ribbon 23 is wound around the ink ribbon reel 22. The tape 16 and the ink ribbon 23 have various widths from about 10 mm to about 50 mm depending on the application.

The tape 1 is inserted into an opening of a concave portion 19 (head receiving portion) formed on the upper portion of the tape cassette 15.
6 and the ink ribbon 23 are overlaid and inserted, and below them, the thermal head 7 of the printer 1 is inserted and arranged. Facing the thermal head 7, the tape 16 and the ink ribbon 23 are sandwiched between the thermal head 7 and
A platen roller 8 is provided.

During printing, the thermal head 7 rotates upward, and a heating element disposed at the tip thereof comes into pressure contact with the platen roller 8 via the ink ribbon 23 and the tape 16, and The ink is thermally transferred to the printing surface of the tape 16. Transferred portion 2 of ink ribbon 23
3 'is taken up by an ink ribbon take-up reel 24, whereby an unused portion of the ink ribbon 23 is pulled out from the ink ribbon reel 22 and supplied to the printing section.

The tape 16 is rotated by the platen roller 8 in a counterclockwise direction, so that the unused portion is pulled out from the tape reel 21 on the one hand and the printed portion 1 on the other hand.
6 'passes through the tape cutter 12 and the tape discharge port 13
Is sent out. At this time, for example, in the case of a black printer, the printed tape 16 ′ sent to the outside after the printing is completed is automatically cut by the tape cutter 12.

In the case of a printer for full-color printing, the thermal head 7 is once separated from the printing position, and the tape 16 is rewound by a predetermined length. Ink ribbon 2
In 3, inks of the three primary colors of magenta, cyan, and yellow are subtractively applied in the longitudinal direction, and an ink portion of the next color to be applied is set as a printing position. Printing, rewinding, and printing are repeated in the same manner as described above, and when the overprinting of three colors is completed, the printed portion 16 ′ passes through the tape cutter 12 and is sent out of the tape discharge port 13 to the outside. . In this case as well, the printed tape 16 ′ sent to the outside is automatically cut by the tape cutter 12.

FIG. 3A is a plan view of a cutting mechanism for performing the above-described cutting, FIG. 3B is a side view thereof, and FIG. 3C is a top view thereof. The cutting mechanism shown in these figures corresponds to FIG.
It is arranged from the upper part of the tape cassette storage part 6 shown in FIG. FIG. 3 (a), (b) or (c)
2A also shows the thermal head 7, platen roller 8, tape reel support pin 9, and ink ribbon take-up drive shaft 11 shown in FIG. 2A to show the positional relationship of the cutting mechanism.

The thermal head 7 has a fulcrum shaft 2 whose rear end supports the upper end of a head arm 25 so as to be rotatable.
6 and locked to the head arm 25. A long slot 27 is formed in the head arm 25 along the longitudinal direction, and a cam pin (not shown) is slidably fitted in the long slot 27. A pull spring 28 is interposed between the lower end of the head arm 25 and the main body frame to urge the head arm 25 in a counterclockwise direction.
Another tension spring 29 is interposed between the vicinity of the upper end of the main body and the main body frame to urge the head arm 25 in the clockwise direction. When a cam (not shown) is driven and the pin fitted in the slot 27 moves to the left in the figure, the head arm 25, that is, the thermal head 7, rotates clockwise about the fulcrum shaft 26 as a fulcrum. When the cam pin (not shown) moves to the right in the figure, the head arm 25
In other words, the thermal head 7 rotates counterclockwise about the fulcrum shaft 26 as a fulcrum, and the printing portion (heating element array) at the tip thereof becomes the tape 16 and the ink ribbon 23 (FIG. 2).
(See (a)).

The tape reel support pin 9 is
An ink ribbon winding drive shaft 11 is rotated by being engaged with a tape rewind gear 31 connected to a drive system (not shown).
Is rotated by being engaged with an ink ribbon winding gear 32 which is also connected to a drive system (not shown).

The platen roller 8 has a platen gear 33, which meshes with a small diameter gear of the transmission gear 34. The large diameter gear of the transmission gear 34 meshes with a drive gear 36 of a stepping motor 35. Thus, when the stepping motor 35 rotates in both the forward and reverse directions, the platen roller 8 is driven to rotate in both the forward and reverse directions via the transmission gear 34. The tape on which printing has been completed by the thermal head 7 and the platen roller 8 is discharged out of the apparatus (to the right in FIG. 3A).

Then, a cutting mechanism is disposed above these devices and between the main frame and the apparatus. In this cutting mechanism, a DC motor (which may be a stepping motor) 3
The worm gear 38 is fixed to the drive shaft, and the worm wheel 39 meshes with the worm gear 38. A large-diameter gear of a reduction gear 41 meshes with a small-diameter gear 40 integral with the worm wheel 39.
A spur gear 43 integral with the bevel gear 42 meshes with one small-diameter gear. Another bevel gear 44 meshes with the bevel gear 42. Thus, the rotation of the bevel gear 42 driven by the DC motor 37 in the horizontal direction (the plane direction of the printer main body) is converted into the rotation of the bevel gear 44 in the vertical direction (vertical direction of the printer main body). .

A scissors cam 46 is coaxially connected to the bevel gear 44. As shown in FIG. 4B, the scissors cam 46 has a detection switch 51 near the circumferential surface as shown in FIG. 4B (the left side of the figure is the upper surface of the printer body and the right side is the lower surface of the printer body). It is arranged on the frame of the printer body. The detection switch 51 detects the reference position of the scissors cam 46 (the cam position corresponding to the initial position where the scissors of the tape cutter are fully opened) by a concave portion provided at a predetermined position on the circumferential surface of the scissors cam 46. .

The scissors cam 46 has a pin 47 projecting from the lowermost edge at the reference position. The pin 47 is slidably fitted into a long hole 53 of a rotary arm 52 integral with the movable blade 12a of the tape cutter,
It is formed so as to be bent outside of 3 so as not to deviate from the engagement with the long hole 53. As described above, the scissors cam 46 is driven to rotate counterclockwise by the DC motor 37 via the worm gear 38, the worm wheel 39, the small diameter gear 40, the reduction gear 41, the spur gear 43, the bevel gear 42, and the bevel gear 44. Then, the pin 47 causes the rotating arm 52 to rotate vertically about the fulcrum shaft 54 as a fulcrum. Thereby, the movable blade 12a opens and closes with respect to the fixed blade 12b, whereby the tape 16 'with print is automatically cut.

FIGS. 4 (a) to 4 (f) are views showing an operation state of the automatic cutting by the scissors cam 46 driven by the DC motor 37 and the movable blade 12a of the tape cutter. FIG. 3 (a) is a reproduction of FIG. 3 (b), in which only parts relating to automatic cutting are illustrated, and other parts are not shown. FIG. 4A shows a state where the scissors cam 46 is at the reference position (home position). The position of the scissors cam 46 is detected when the tip of the detection switch 51 projects to a position where it comes into contact with the center 46-1 of the concave portion of the scissors cam 46 as shown in FIG.

In the state shown in FIG. 1, that is, FIG.
Reference numeral 7 denotes a stop at a substantially intermediate position of the elongated hole 53, whereby the rotary arm 52 stops horizontally. Further, thereby, the movable blade 12a is maximally opened with respect to the fixed blade 12b.

When the DC motor 37 starts to rotate, the pin 47 starts to move in a counterclockwise direction as indicated by an arrow A1 in FIG. Then, an arrow A2 in FIG.
When the pin 47 reaches the right end of the long hole 53 by continuing the circular movement as shown in FIG. 3, the movable blade 12a starts to perform shearing (cutting of the tape 16 ') with the fixed blade 12b.

With the continued rotation of the scissors cam 46,
As shown by an arrow A4 in FIG. 4D, the pin 47 further moves in a circle and returns to the left of the long hole 53 to further raise the rotating arm 52, thereby moving the movable blade 12a in the counterclockwise direction. Of the movable blade 12a and the fixed blade 1
2b is completely closed. This completes the shearing of the tape cutter.

The scissors cam 46 further continues to rotate,
As shown by the arrow A5 in (e), the pin 47 further moves circularly past the intermediate point of the elongated hole 53, and thereby the rotating arm 5 is moved.
2 starts to be pushed down, whereby the movable blade 12a starts rotating clockwise and starts to open with respect to the fixed blade 12b. Then, as shown by an arrow A6 in FIG.
The circular movement of the pin 47 is continued to reach the left end of the long hole 53, the rotation of the rotating arm 52 and the movable blade 12a is continued in the clockwise direction, and the scissors cam 46 is further moved to the state shown in FIG. The following interlocking operation is continued, and stops at the reference position by the detection switch 51 detecting the center 46-1 of the concave portion.

As described above, the automatic cutting is performed by the DC motor 37.
, The movable blade 12a of the tape cutter is driven, and the tape 16 'is cut. During the automatic cutting, when a foreign object or the like is caught in the tape cutter and the shearing operation of the movable blade 12a is locked, the movable blade 12a is locked.
1 is immediately detected by the control circuit of FIG. 1, the scissors cam 46 is reversed, and the movable blade 12a is rotated to the initial position. The operation of the control circuit will be described below.

First, the control circuit, as shown in FIG.
PU (Central Processing Unit) 58, DC motor driver I
C (integrated circuit) 59, three resistors R1, R2, R3, etc. The drive power supply VDD of this control circuit branches at the point P via the resistor R3, and one of the branch lines is input to the input port s of the CPU 58. The other branch line is input to one terminal 51-1 of the detection switch 51 via the resistor R2. The other terminal 51-2 of the detection switch 51 is connected to the ground side of the control circuit.

Thus, as shown in FIGS. 1 and 4 (a), the detection switch 51 is connected to the center 4 of the recess of the scissors cam 46.
When it is turned on in contact with 6-1, the power supply VDD
Flows to the detection switch 51 side, the branch point P, that is, the voltage of the input port s of the CPU 58 is “L”. On the other hand, as shown in FIGS. 4B to 4F, while the scissors cam 46 starts and continues to rotate forward in the counterclockwise direction indicated by the arrow B in the drawing, the detection switch 51 moves to the circumferential portion of the scissors cam 46. Then, the power supply VDD does not flow to the detection switch 51 side, so that the branch point P, that is, the voltage of the input port s of the CPU 58 becomes “H”.

FIG. 5 shows the DC motor drive instruction signals Fn and Rn output from the CPU 58 and the corresponding DC motor drive instruction signals Fn and Rn.
9 is a chart showing a relationship between a drive current output from the motor driver IC 59 to the DC motor 37 and voltages of wirings OUT1 and OUT2. The CPU 58 controls the tape cutter 12
When the shearing operation is performed on the movable blade 12a of FIG. 1, after confirming that the voltage of the input port s of FIG.
In order to rotate the motor 37 forward (forward rotation), as shown in FIG. 5, one signal Fn of the DC motor drive instruction signal is set to "H" and the other signal Rn is set to "L" and output to the DC motor driver IC 59. I do. DC motor driver IC59
Sets the voltage of one wiring OUT1 to “H” and sets the voltage of the other wiring OUT2 to “L” and outputs it to the DC motor 37. As a result, the DC motor 37 rotates forward, and FIG.
As shown in (a) to (f), the movable blade 12a is rotated toward the fixed blade 12b via the scissors cam 46, and sheared,
Return to the initial position.

While the scissors cam 46 is rotating forward, the voltage at the input port s becomes "H", so that the CPU 58 determines that the movable blade 12a is operating. When detecting an abnormal stop of the movable blade 12a due to, for example, the presence of a foreign substance, the CPU 58 returns the movable blade 12a to the initial position from the middle of the shearing operation, that is, in order to reversely rotate (reversely rotate) the DC motor 37, As shown in FIG. 5, one signal Fn of the DC motor drive instruction signal is set to "L" and the other signal Rn is set to "L".
n is inverted to “H” and output to the DC motor driver IC 59. In response, the DC motor driver IC 59 changes the voltage of the wiring OUT1 to “L”, reverses the voltage of the wiring OUT2 to “H”, and outputs the same to the DC motor 37. Accordingly, the DC motor 37 rotates in the reverse direction, and rotates the movable blade 12a via the scissors cam 46 from the middle of the shearing operation to the initial position.

FIG. 6 is a timing chart of each voltage change in the case where the abnormal stop of the movable blade 12a is detected and the DC motor 37 is rotated in the reverse direction as described above. This figure shows, from the top, the voltage of the wiring OUT1, the voltage of the wiring OUT2, the voltage of the input port s, the potential difference (V2−V1) between both ends of the resistor R1 attached to the wiring OUT1, and the time.

The potential difference between both ends of the resistor R1 (V2-V
1) is measured inside the CPU 58. This potential difference (V2-V1) is proportional to the value of the current flowing through the DC motor 37, so that the potential difference (V2-V1)
The value of the current flowing through the motor 37 can be determined.

At time t ₀ in FIG.
When the DC motor driver IC 59 drives the DC motor 37 forward by setting the voltage of the wiring OUT1 to “H” and the voltage of the wiring OUT2 to “L” by the C motor drive instruction signal (Fn, Rn), the detection switch is almost immediately turned on. When the switch 51 is turned off, the voltage of the input port s becomes “H”, and it is confirmed that the scissors cam 46 starts rotating in the counterclockwise direction. The potential difference (V2-V1) indicates a normal value Va.

[0041] Then, at time t ₁ after approximately 1.5 seconds, when the movable blade 12a, or caught foreign matter on the tape cutter abnormally stops, DC motor 37 is locked, and thus the resistance value in the motor is extremely DC motor 37
The current flowing through becomes extremely large. Thereby, the wiring O
FIG. 6 also shows the potential difference (V2−V1) between both ends of the resistor R1 of the UT1.
As shown in FIG. Thereby, the CPU 58 immediately detects that the DC motor 37 is locked.

At time t2, immediately after the lock of the DC motor 37 is detected, the CPU 58 reverses the output of the DC motor drive instruction signal (Fn, Rn) as shown in FIG. As shown in FIG. 6, wirings OUT1 and OU output from the DC motor driver IC 59 are provided.
The voltage of T2 is reversed. The potential difference (V2-V1) indicates a minus normal value Vb, whereby it is recognized that the DC motor 37 is normally rotating in the reverse direction. Eventually time t ₃
Thus, it is confirmed that the scissors cam 46 has returned to the initial position, that is, the tape cutter has returned to the initial position, when the voltage of the input port s becomes "L". Thereby, the CPU 58 outputs the DC motor driving instruction signal (Fn, R
The output of n) is turned off, and accordingly, the voltages of the wirings OUT1 and OUT2 output from the DC motor driver IC 59 are also turned off, and the DC motor 327 stops.

[0043]

As described above in detail, according to the present invention, the abnormal stop of the cutter is detected by the current flowing through the motor of the drive source, so that the abnormal stop of the cutter can be detected earlier. Since the lock time of the motor can be minimized, damage due to overload of the motor, the drive transmission gear train, and the like can be prevented, and therefore, the service life of the entire apparatus can be prolonged, thereby contributing to the benefit of the user. . Further, since the abnormal stop of the cutter can be detected early only by adding one resistor and two wires without changing the basic configuration of the control circuit, there is no possibility of increasing the product cost. Can also contribute to the interests of the user.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a control circuit that controls a tape cutting device of a printer according to an embodiment.

2A is a perspective view showing the printer together with a tape cassette, and FIG. 2B is a plan sectional view of the tape cassette.

FIG. 3A is a plan view of a cutting mechanism that performs cutting, and FIG.
Is a side view, and (c) is a top view.

FIGS. 4A to 4F are operation state diagrams for automatically cutting a tape by a scissors cam driven by a DC motor and a movable blade of a tape cutter.

FIG. 5 shows a DC motor drive instruction signal output by the CPU of the control circuit, and a DC motor driver IC corresponding to the DC motor drive instruction signal.
5 is a table showing a relationship with a drive current output to a C motor.

FIG. 6 is a timing chart of each voltage change when the DC motor is rotated reversely upon detection of an abnormal stop of the movable blade.

FIG. 7 is a diagram showing an example of a conventional tape cutter.

FIG. 8 is a time chart of a drive system in a case where a control unit determines that a foreign matter is present in a conventional tape cutter.

[Explanation of symbols]

 Reference Signs List 1 printer 2 housing 3 key input unit 4 operation key 5 display unit 6 tape cassette storage unit 7 thermal head 8 platen roller 9 tape reel support pin 10 cassette case 11 ink ribbon take-up drive shaft 12 tape cutter 12a movable blade 12b fixed blade Reference Signs List 13 Tape discharge port 13-1 R forming member 15 Tape cassette 16 Tape 16 'Tape-printed portion 17 Tape reel hole 18 Ink ribbon take-up reel hole 19 Depression 21 Tape reel 22 Ink ribbon reel 23 Ink ribbon 23' Ink ribbon transferred Part 24 Ink ribbon take-up reel 25 Head arm 26 Support shaft 27 Long slot hole 28 Pull spring 29 Pull spring 31 Tape rewind gear 32 Ink ribbon take-up gear 33 Platen gear 34 Transmission gear 35 Step Ping motor 36 Drive gear 37 DC motor 38 Worm gear 39 Worm wheel 40 Small diameter gear 41 Reduction gear 42, 44 Bevel gear 43 Spur gear 46 Scissor cam 46-1 Center of recess 47 Pin 51 Detection switch 52 Rotating arm 53 Long hole 54 Support shaft

Claims (1)

[Claims] A printing means for printing on a printing medium; a first cutting blade; an initial position having a predetermined relative positional relationship with respect to the first cutting blade; and a printing means cooperating with the first cutting blade. A pair of cutter members comprising a second cutting blade movable between a shearing position in which the printed medium to be printed is completely sheared from the main body of the printing medium and a shearing position; A driving mechanism comprising: a cutter power source for supplying power for performing a moving movement between the cutter member and the shearing position; and a power transmission mechanism for transmitting the power of the cutter power source to the cutter member. Cutter control means, a load detection means for detecting a load on the power source during a movement operation of the second cutting blade from the initial position to the shear position, and an overload detection by the load detection means. Zui and printing apparatus characterized by comprising a return control unit for controlling the cutter controller to return the cutter member to the initial position.