JPS5856872A - Thermal printer - Google Patents

Abstract

PURPOSE:To increase printing speed and to make power consumption small, in a compact serial thermal printer, by releasing compression of a platen to a thermal head by actuating a clutch when a head sending mechanism is reversed by a spiral cam. CONSTITUTION:When a motor 3 starts rotation in the direction of an arrow A, a head sending cam 6 and a driving shaft 8 are rotated in the direction of an arrow C through gears 5 and 7. A head 26 begins to return to the direction of an arrow J. A clutch gear 9 is imparted by torque in the direction of the arrow C via a coil spring 13. A pawl 10-a of a clutch pawl wheel 10 is contacted with a stopper 12. The gear 9 is rotated in the direction of the arrow C by theta deg. until the clutch pawl wheel 10 is engaged, with the coil spring 13 being slackened. A platen relay cam 17 and an intermittent gear 18 are rotated in the direction of E. The compression of a platen 24 to the head 26 is released. Therefore even though the head 26 is returned at a high speed, the head surface is not rubbed and the abrasion can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a small serial type thermal printer that performs printing by moving a vertical head in the digit direction.

Conventionally, in serial printers, printing was performed by pressing the thermal head against the thermal recording paper on the platen, and it was necessary to release the pressure between the thermal head and platen, feed the paper, and return the thermal head. Therefore, a head feeding mechanism using a helical cam with a reverse stroke as described in Japanese Patent Publication No. 47-6.528, and USF-425
By using a mechanism such as that described in No. 0808 and converting the printer into a cycle machine, thermal printers have been made smaller and lower in price. However, with cycle machines, even if the desired number of print shifts is small, the operation is always equivalent to printing the maximum allowable number of digits, making it difficult to increase the practical printing speed, wasting power, and reducing head life due to wear. This method had drawbacks such as a decrease in paper speed and the inability to rapidly advance the paper.

In addition, if the head is returned from an arbitrary position, other power sources or complicated mechanisms are required to operate the paper feed, platen release, etc., making the printer more compact and cost-effective. This was a detriment to pricing.

The present invention eliminates such drawbacks, and its purpose is to:
The first objective is to provide a thermal printer with high actual printing speed. The second objective is to provide a thermal printer with low power consumption. The third object is to provide a printer capable of rapidly feeding paper. Fourthly, length is smaller and cheaper.

Examples of the present invention will be described below. Figure 1 is a perspective view showing the structure of the printer, Figures 2, 3, and 4 are paper feed,
A side view showing one platen release, and FIG. 5 is a time chart showing the operation of the printer.

In Fig. 1, 1 is a frame having a guide portion 1-a of an FPC (flexible printed circuit board) 2, 03 is a motor fixed to the frame 1, and 4 is a motor gear fixed to the rotating shaft of the motor 3. , 5 is an intermediate gear, 6 is a head feed cam rotatably mounted on the frame 1, and a helical groove 6-
a, and the cam gear 7 and clutch drive shaft 8 are coaxially fixed. 9 is a clutch gear rotatably attached to the clutch drive shaft 8, 10.11 is a clutch pawl rotatably attached to the drive shaft 8, and 12 is a clutch pawl 10.1.
a stopper that can be secured to the claws 10-a and 11-a of 1;
3 is a coil spring whose inner diameter is slightly smaller than the outer diameter of the drive shaft 8; the coil spring is pushed into the drive shaft 8, and one end is connected to the clutch gear 9;
The drive shaft 8, clutch gear 9, clutch pawl 10, and coil spring B form a spring clutch mechanism. However, when the drive shaft 8 rotates in the direction of arrow C, the inner diameter of the coil spring 15 tightens on the clutch gear 9, which has a rotational load, so the torque in the direction of arrow C is transmitted through the coil spring 15, causing the gear to rotate in the direction of arrow C. However, when the clutch pawl 10 is locked, the inner diameter of the coil spring 15 is loosened, so torque is transmitted. When the drive shaft 8 rotates in the direction of the arrow, the coil spring 1
Since the inner diameter of the clutch gear 5 is loosened, only an extremely small torque is transmitted to the clutch gear 9 compared to the rotational load, so the clutch gear 9 is prevented from rotating. 14 is also coil spring 1
A coil spring similar to 5 is press-fitted into the drive shaft, etc., and the clutch gear 9 transmits torque in the direction of the arrow only when the drive shaft 8 rotates in the direction of the arrow and the clutch pawl 11 is not engaged. 0 and flanch claw leather 1 rotating in the direction of the arrow
0 and Franch D nails 11 are mutually nails 10-a, (11-
In the down position where a) corresponds to the stopper 12 and is locked, the other claw's back 1l-C1 (10-C) is in such a phase that it does not come into contact with the stopper. (See Figures 3 and 5 1
Reference numeral 6 refers to an operating gear 11 which meshes with the clutch gear 9 so as to reduce or maintain constant speed, is rotatably attached to the shaft 23, and is integrally formed with a platen release cam 1° 7 and an intermittent gear 18 for paper feeding. is a paper feeding gear that meshes with the intermittent gear 18; and a locked part 19 that is locked to the locking part 18-a of the intermittent gear 18.
-a and 19-b, and is rotatably attached to the paper feed roller shaft 20, which is mounted on the frame 1 and rotates in unison with the paper feed roller company. A coil spring (-
1 is press-fitted into the paper feed roller shaft 20, and one end is connected to the paper feed gear 1.
Even if the paper feed gear 19 rotates reciprocatingly, the paper feed roller shaft 20 receives a paper feed load, and the paper feed gear 19 rotates in the direction of arrow G. Only when this occurs, it acts as a one-sided clutch that rotates in the direction of arrow G.

A platen 24 is rotatably attached to the paper feed roller shaft 20 and attached in the direction of arrow H by a spring member 25, and has a cam support lower 24-a that can be engaged with the platen release cam 17.

25 is a carriage supported on a guide shaft 27 for holding the thermal head 26, and a 2-sen groove of the head feed cam 6;
6- has a pin (not shown) that engages with a. 28 is a detector that generates a signal to specify the printing start position;
A series of operations by such a mechanism will be described below with reference to FIG. 5.

In Fig. 5, 101 is the rotation direction of the motor 3, and 10
2 is a graph showing printing, 105 is the operation of the head 26, 104 is the operation of the clutch gear 9, 105 is the operation of the brates, 106 is the operation of the paper feed gear 19, and 107 is a graph showing the paper feed operation by the paper feed roller 22. , the solid line indicates single line printing, and the two-dot chain line indicates continuous printing. Yes, the head feed cam 6 rotates one or more times in the direction of arrow C from the printing start position defined by the carriage, the screw 25, the head 26 stripe, and the detector 28 (strictly speaking, from the state shown in Fig. 2 to the state shown in Fig. 4). Clutch pawl mold 10.11, platen release cam 18, intermittent gear 18, paper feed gear 19,
The platen cam follower 2a-A is in the down position as shown in FIG.
The clutch pawl type 10 car is engaged, and the flatten 2
4 is released from the head 26 by the platen release cam 17, and the paper feed strip 17 is locked by the intermittent teeth M-1B at the locking portion 19.

(2) Preparation for printing (To=T*) When the motor 3 starts rotating in the direction of arrow B at To, the head feed cam 6, cam gear 7, and drive shaft 8 move to the intermediate tooth $-5.
The carriage 25 and the head 26 are rotated by applying torque in the direction of the arrow through the head feed cam 6, and the carriage 25 and head 26 are moved in the direction of the arrow by the head feed cam 6 along the guide shaft 27, and reach the printing start position at T4.

During this time, the clutch gear 9 is tightened by the coil spring 14, so a torque is applied to the clutch gear 9 in the direction of the arrow through the coil spring 14, and as shown in FIG. The clutch claw 11-a comes into contact with the stopper 12, the coil spring 14 is loosened, and the clutch claw mold 11 rotates 00 times in the direction of the arrow until it is locked, and then stops at TsK in the state shown in FIG. 2. The platen release cam 17 and the intermittent gear 18, which are integrally molded with the operating gear 16 that meshes with the clutch gear 9, are T. At the same time as the clutch gear 9 starts rotating in the direction of the arrow F, the clutch gear 9 starts rotating in the direction of the arrow F, and after some delay from To, the clutch gear 9 first engages the meshing portion 18-b of the intermittent gear 18 and the paper feed.
The meshing portion 19-d of the gear 19 meshes with the paper feeding gear 19.
rotates in the direction of arrow H as shown in graph 106, but since the inner diameter of the coil spring 21 is loosened, the paper feed roller shaft 20 and the paper feed row 222 do not rotate. When it rotates further, the intermittent gear 18 and the paper feed gear 19 end their engagement, and the paper feed gear 19 engages with the general locking part 19-a and the locking part 18-a of the intermittent gear 18.
When it is locked and eventually reaches T, it comes into contact with the large radius part of the platen release cam 17 between To and T, and the head 26
As shown in graph 105, the cam follower 24-a of the platen 24, which had been released from the pressure, rotates in the direction of arrow H due to the biasing force of the spring member 25 while contacting the radius changing portion of the platen release cam 17, and rotates in the direction of arrow H, as shown in graph 105. Once reached, the platen 24 is pressed against the head 26 and the operating gear 16
is rotated by the clutch gear 9, the platen 2
4 cam 7 oror 24-a and graten release cam 17
0 (3) Printing (T4~Ts) At T, the head 26 reaches the print start position defined by the detector 28. Then, the head is pressed 4 to print the desired number of digits, and when the desired number of digits has been printed, T is pressed.
At , the rotational direction of the motor 5 is reversed from the arrow B direction to the arrow A direction. T4 to T.

During this time, since the coil springs 13 and 14 are relaxed, the gear train after the clutch gear 9 does not operate in the state shown in FIG. 2, and the pressed state of the platen 24 and head 26 is maintained.

(4) Platen release/paper feed (Ts=Tt.)T,
When the motor 3 starts rotating in the direction of arrow A, the head feed cam 6 is rotated through the intermediate gear 5 and the cam gear 7.
, the drive shaft 8 starts rotating in the direction of arrow C, and the head 26 starts returning in the direction of arrow J. When the drive shaft 8 rotates in the direction of arrow C, the coil spring 13 tightens, so the clutch gear 9
is applied with a torque in the direction of arrow C via the coil spring 13, and from the state shown in FIG. 13 becomes loose and the clutch pawl type 10 is rotated 00 times in the direction of arrow C until it is stopped at TIG as shown in FIG. a platen release cam 17 integrally molded with the operating gear 16 that meshes with the clutch gear 9;
The intermittent gear 18 starts rotating in the direction of arrow E at the same time as the clutch gear 9 starts rotating in the direction of arrow C at TI5,
At T6, the cam follower 24-a of the platen 24 and the radius changing portion of the platen release cam 170 contact each other, and the platen 2
4 rotates in the direction of arrow G along the cam lead of the platen release cam 17 against the urging force of the spring member as shown in the graph 105, and at T-f, the cam follower 2 of the platen 24
4-a reaches the large radius part of the platen release cam 17, the platen release operation is completed, and the platen 24 is moved to the head 2.
6 is released and the platen release cam 17 further rotates, the released state is maintained.
-a is engaged and locked 0 Furthermore, the clutch gear 9 rotates in the direction of arrow f:rJC, the intermittent gear 16 rotates in the direction of arrow E, and the intermittent gear 18 rotates in the direction of arrow E until reaching T8. The meshing part 18-b of the gear 18 and the meshing part 19- of the paper feeding gear 19
d meshes, and the paper feed gear 19 starts rotating in the direction of arrow G. When the paper feed gear 19 rotates in the direction of arrow G, the inner diameter of the coil spring 21 is tightened, and the paper feed roller shaft and paper feed roller 22 start rotating in the direction of arrow G. The intermittent gear 18 further rotates in the direction of arrow E, and when it reaches T9, the fourth
As shown in the figure, the locking part 18-a of the intermittent gear 18 and the paper feed gear 1
The locked portion 19-b of 9 is engaged, the paper feed gear 19, the paper feed roller shaft 20, and the paper feed roller 22 are stopped, and paper feeding is completed. Even after paper feeding is completed, the clutch gear 9 continues to rotate in the direction of arrow C and T. Flanch nail upper 10 nail 10-a
When the coil spring 16 comes into contact with the stopper 12, the inner diameter of the coil spring 16 is loosened, and the gear train after the clutch gear 9 stops in the state shown in FIG.

(5) Head return (Ts~T, ,) Prior to platen release and paper feeding, when the motor 5 starts rotating in the direction of arrow A at T6, the head feed cam 6 rotates in the direction of arrow C, and the head 26 starts returning in the direction of arrow J. At Tll, the head 26 moves in the direction of arrow J and passes the printing start position defined by the detector 28, and the head feed cam 6 further reaches the clutch gear 90 rotation angle 00 or more defined by the clutch pawl type 10.1ic. When the motor 3 rotates, the motor 3 stops, the head return is completed, and the one-line printing process is completed. In addition, in the case of continuous printing, motor 5 at T'+2
When is reversed in the direction of arrow B, printing preparation, printing, platen release, paper feed, and return are performed as in (2) to 0.

(6) To prepare for paper fast-feeding, start rotating the motor 5 in the direction of arrow B at the normal printing process timing position and 0 standby position, which corresponds to printing preparation. direction and rotate until it reaches the printing start position. During this time, as in the printing preparation process, the clutch gear 9, clutch pawl mold 10
．． 11 rotates θ0 in the direction of the arrow, the operating gear 16, grating/reed cam 17, and intermittent gear 18 rotate in the direction of arrow F, and the paper feed gear 19 rotates in the direction of arrow H while loosening the coil spring 21, from the state shown in FIG. The state shown in Figure 2 is reached, and the preparation for fast-forwarding the paper is completed.

When the head 26 reaches the printing start position, the motor 5 reverses its rotational direction from the direction of arrow B to the direction of arrow A, the head feed cam 6 rotates in the direction of arrow C, and the head 26 moves in the direction of arrow J to start the timing. Rotate until the position is reached. During this time,
Similar to the platen, release, and paper feeding operations in the normal printing process, the clutch gear 9 and the clutch pawl 10 and 11 are connected to the arrow C.
The operating gear 16 rotates in the direction of arrow E. While rotating in the direction of arrow E, the platen release cam 17 rotates the platen 24 in the direction of arrow G against the biasing force of the spring member 25, releasing the pressure from the head 26, and the intermittent gear 18 also rotates in the direction of arrow E. , meshes with the radial feed gear 19 whose platen release operation has been completed, the paper feed gear 19 rotates in the direction of arrow G while tightening the coil spring 21, and rotates the paper feed roller shaft 20 and the paper feed roller 22 in the direction of arrow G. Then, the paper feed operation is carried out, and the paper feed for one line is completed by a series of operations of 5 o or more.The above series of operations, such as reversing the head feed cam 6 every θ0, is repeated to perform rapid paper feed.

As described above, according to the present invention, even if the head is returned from any position, operations such as releasing the pressure between the head and platen and feeding the paper are possible using a simple mechanism, and the practical printing speed is high and the power consumption is high. To provide a thermal printer which has no wastage, has a long head life related to wear and tear, can rapidly feed paper, and can be made smaller and lower in price.

[Brief explanation of the drawing]

FIG. 1 is a perspective view for explaining the configuration and operation of a thermal printer according to the present invention; FIGS. 2, 5, and 4 are side views of a train wheel for explaining grating release and paper feeding operations; Fifth
The figure is a time chart of the normal printing process. 1 Frame 2 FPC 5 Motor 4 Motor gear 5 Intermediate gear 6 Head feeding cam 7 Cam gear 8 (Clutch) drive shaft 9 Clutch gear 10 Clutch pawl type 11 Clutch pawl type 12 Stopper 15 Coil spring 14 Coil spring 15
Clutch fixing bin 16 Operating gear 17 Platen release cam 18 Intermittent gear 19 Paper feed gear 20
Paper feed roller shaft 21 Coil spring 22 Paper feed row 225 Shaft 24 Platen 25 Spring member 26 (thermal) head 2
7 Guide shaft 28 Detector 29 Spring hook is 0 or more Applicant: Shinshu Seiki Co., Ltd. Patent attorney, Tsutomuichi Mogami, explanation, Figure 2, Figure 3, Figure 4, Procedural amendment (voluntary), 1930, October On the 8th, Mr. Commissioner of the Japan Patent Office 1, Indication of the case, Patent Application No. 155206 of 1982, 2, Name of the invention - Malprinter 3, Person making the amendment 4, Agent 5, Number of inventions increased by amendment Procedural amendment (Addressed to myself) 1. The scope of the patent claims has been amended as follows. [1, Move the thermal head in the digit direction [9]. In a serial thermal printer that prints by pressing the thermal head onto gold thermal recording paper on a platen, a drive shaft rotates an arbitrary amount in both directions to reciprocate the thermal head, and a reversal operation of the drive shaft is used as a trigger to reciprocate a predetermined amount. A thermal printer comprising: a clutch means for obtaining rotation; a platen release means that engages with the clutch means and moves slowly; and a paper feed means that engages and interlocks with the clutch means. 2. When the clutch means is a driven body rotatably attached to the drive shaft, one end is fixed to the driven body, and a load is applied to the driven body. Two coil springs are inserted into the drive shaft so that the inner diameters of the coils are adjusted against opposite rotations of the drive shaft, and one end of the coil springs that is not fixed to the driven body is fixed to the drive shaft. two pawl shapes pivotally mounted on the shaft N or said driven body. 1% characterized by comprising a stopper that can come into contact with and lock the claw shape! ! ff#11I Thermal printer according to item 1. & The thermal printer according to item 1, characterized in that a one-turn cam is used as the platen release means. 4. An intermittent gear in which the paper feeding means has one locking portion t;
Gear 1 paper feed roller with locking stop S. Paper feed roller shaft integrated with pattern paper feed roller. It is characterized by comprising a 10,000-turn clutch interposed between the front H upper gear and the paper feed roller shaft. Special RT
The thermal printer according to item 1 of the range of f+m. 5. The rotating cam and the intermittent gear are integrally molded,
The phase of the platen release operation and the paper feeding operation is such that there is not more than one of them tl-Characteristics ff#*Required Range Thermal printer described in Items 5 and 4,'' 2. Specification 3 True In the 10th line from the top, the word ``round trip'' has been corrected to ``round trip''. 5. On the 15th line from the top of page 5, the phrase ``Multiple characters printed'' was corrected to t ``Number of digits printed.'' 4. On the 16th line from the top of page 5, the ``number of digits for measurement'' was corrected to ``number of digits allowed.'' 5. On the 12th line from the top of page 4, ``Diagram 1, 1'' was corrected to read ``Miyako 1 wa Pu.''& On the 3rd line from the bottom of the same page, ``Kimple'' was replaced with ``Kipur''. 1. From the same 5th line, the word "not communicated" in the second line was corrected to "not communicated."& On the 8th line from the bottom of page 6, the word ``clutch D claw wheel'' is corrected to read ``clutch claw wheel.'' 9 On the 10th line from the top of the same page 6, ``jurishi shi'' and ``stop'' are corrected to ``butt on.'' 1α On the 11th line from the top of page 6, the word "does not touch" was corrected to "does not touch". 11. On the 12th line from the top of page 6, the word "l@Refer to Figure 5 16" was replaced with "Fig. Reference) 16”
Corrected. 12. On the second line from the bottom of page 6, the phrase "Paper Feed Roller Company" was corrected to "Paper Feed Roller 22." 15 In the 10th line from the top of page 7, the phrase ``Fukutei Sare'' has been corrected to ``Fukusei Sare''. 14゜Page 7, line 12 from the bottom, "Kamfusa Roar" stop f f-+71 A 7
, t Roar” was corrected. 15 In the 5th line from the top of the 8th picture, the word "Plates" is corrected to "Platen" - 1 & 8
On the 6th line from the top of the page, the word ``continuous printing'' was corrected to ``continuous printing''. 11 On the 8th line from the top of the same page, ``Special equipment position'' was corrected to ``Special period position.'' ・1a On the 8th page of the same page, on the 8th line from the top, rTttJ Corrected the word ``Tororu'' to r Ttx J. 19, 48'g4 In the 9th line from the top, the phrase ``time status'' has been corrected to ``temperature letter cram school.'' 2αpffJ In the 12th line from the top of page 8, the word ``limited'' was corrected to ``strict.'' 21. On the 4th line from the bottom of page 8, the word 2a-aJ is corrected to ``24-aJ.'' 22. On the 1st line from the bottom of page 9, ``Restaurant 17 is the lock.'' The word ``teeth jl? is the lock.'' Corrected as "locked part". The 11th line from the top of 25 Dodo 9 is corrected to ``To tighten'' and ``To vrs''. 24. On the 8th line from the top of page 10, the phrase ``generally locked part'' is corrected to ``locked part''. 25. In the 8th line from the top of page 16, the word ``wear and tear'' has been corrected to ``wear.'' 26. January 1st, page 16, line 9 from Saturday, ``Low price'' is corrected to ``Low price J.'' Agent Mogami Mushi

Claims (1)

[Claims] 1. In a serial thermal printer that prints by moving a length-maru head in the digit direction and pressing the thermal head against thermal recording paper on a platen, the thermal head rotates an arbitrary amount in both directions. A drive shaft characterized by: a clutch means for obtaining a predetermined amount of reverse rotation triggered by the reversal operation of the drive shaft; a platen release means that engages and interlocks with the clutch means; and a platen release means that engages and interlocks with the clutch means. A printer comprising a paper feeding means. 2. When the clutch means has one end fixed to the driven body which is rotatably mounted on the drive shaft, and a load is applied to the driven body, Two coil springs injected into the drive shaft so that the inner diameter of the coil tightens against opposing rotations of the drive shaft, one end of which is not fixed to the driven body of the coil spring, The length according to claim 1, characterized in that it comprises two pawls that are pivoted to a shaft or pivoted to the driven body, and a stopper that comes into contact with the pawls and is capable of interfacing. Multiprinter 05 Thermal printer according to claim 1, characterized in that a rotary cam is used as the platen release means 4. The paper feeding means is an intermittent gear having a locking part, It is composed of a gear having a locking part, a paper feed roller, a paper feed roller shaft integrated with the pattern paper feed roller, and a 10,000-turn clutch interposed between the gear and the paper feed roller shaft. Thermal printer 05 according to claim 1, characterized in that the rotary cam and the intermittent gear are integrally molded and have different phases so that the platen release operation and the paper feeding operation do not overlap. Length-multi printer 0 according to the features of claims 3 and 4