JPS60183183A - Paper feeder for serial printer - Google Patents

Abstract

PURPOSE:To enable the reliability of a paper-feeding operation to be enhanced by a relatively simple construction, by a method wherein a paper-feeding pitch can be varied, and can be varied in accordance with the feeding amount of a carriage from a printing region to a non-printing region. CONSTITUTION:When printing in a line is completed in response to a printing command, a pulse motor 3 is reversely rotated to feed a carriage 4 to a home position, where a printing head is separated, and is fed to a non-printing region by an amount corresponding to the paper-feeding pitch, resulting in that a controlling gear body 11 is engaged to a partial gear body 18, which is not rotated at this time under the function of a one-way clutch. When the motor 3 is rotated forward, the carriage 4 rotates the gear body 18 by a predetermined pitch amount, thereby feeding a paper. Accordingly, there is no need for an electromagnetic clutch or the like for stopping the feeding of the carriage when feeding the paper, and the paper can be fed with high reliability by a relatively simple construction.

Description

Detailed Description of the Invention (Technical Field of the Invention) The present invention relates to a filter paper feeding device in a serial type thermal printer, a wire dot printer, a type wheel type printer, etc.
More specifically, the present invention relates to a paper feeding device for a serial printer in which a motor for conveying a carriage also serves as a drive source for feeding paper.

(Background of the Invention) Serial printers of this type are required to be small and lightweight, and relatively often attempts are made to improve the space factor and reduce weight by reducing the number of driving sources. For this reason,
Several attempts have been made to use a single motor as both a carriage conveyance motor and a paper feed motor.

However, in conventional motors that use a single motor to carry both carriage transport and paper feed, the clutch is turned on immediately when the carriage returns to its initial position or when the carriage moves from the printing area to outside the printing area. The rotation of the motor is transmitted to the paper feed shaft to move the paper by a predetermined pitch, but since the paper feed weight is always a fixed pitch, it is not possible to change the line spacing of the print data. Ta. To solve this problem, it may be possible to reverse the carriage and turn on the clutch at a predetermined position, at the same time causing the carriage reverse transport mechanism to idle, and to control the rotation amount of the motor during this time to vary the paper feed repitch. However, in this case, since the paper is fed immediately after the clutch is turned on, consideration must be given to the overconcentration response characteristics, which poses problems in terms of freedom of control and assembly management.

(Object of the Invention) Therefore, it is an object of the present invention to provide a paper feeding device that can vary the paper feeding pitch in a serial printer in which a single motor carries out carriage conveyance and paper feeding.

Another object of the present invention is to provide a paper feeding device that is easy to control and has high operational reliability, without requiring any means for not transmitting the rotation of the motor during paper feeding to the carriage conveying means. It is in.

(Structure of the Invention) In order to achieve the above object, the paper feeding device for a serial printer of the present invention includes a carriage mounted with a print head and transported in a direction perpendicular to the paper transport direction, and a carriage that is transported in forward and reverse directions. A motor that rotates in forward and reverse directions to convey and drive the carriage, and a motor that changes the paper feeding pitch according to the amount of conveyance of the carriage from the printing area to the outside of the printing area, and a motor that rotates when the carriage is outside the printing area. The present invention is characterized by comprising a paper feeding means that selectively transmits either forward rotation or reverse rotation.

(Embodiment of the Invention) Figures 1 to 6 relate to one embodiment of the present invention, in which Figure 1 is a plan view of the main part, Figures 2 and 3 are explanatory diagrams of the intermittent gear mechanism, and Figure 4 5 is an explanatory diagram of a one-way clutch, FIG. 5 is a side view showing the carriage, and FIG. 6 is an explanatory diagram showing the relationship between carriage movement and paper feeding.

In FIG. 1, reference numeral 1 denotes side plates of the printer frame, and although their heads are not shown, two side plates are provided facing each other. Reference numeral 2 denotes a rotating shaft rotatably held between the side plates 1.1, which is rotated in forward and reverse directions by the drive of the pulse motor 3. Reference numeral 4 denotes a carriage slidably held on the rotating shaft 3, on which a print head 5 (also shown in FIG. 5 as a thermal head in the embodiment) is mounted. Reference numeral 6 is an integral screw, which is held between the support frames 4a, 4a of the carriage 4, and is connected to the rotating shaft 2 with a spline shaft, which has a non-circular cross section (in the embodiment, a part of the curved surface is rubbed off in the longitudinal direction). (It is inserted so that it can slide freely but rotates integrally.) Reference numeral 7 denotes a rack body that is stretched between the side plates 1.1, and toothed portions that mesh with the toothed portions of the screw unit 6 are formed alternately over the entire movement area of the carriage, which will be described later. Therefore, when the pulse motor 3 rotates forward, for example, the screw unit 6 moves to the right in the figure, and when the pulse motor 3 reverses, the screw unit 6 moves to the left in the figure, and the carriage 4 is transferred forward and backward. .

Reference numeral 8 denotes a support shaft that is slidably held between the support frames 4a, 4a of the carriage 4, and has a pressing body 9 fixed to its tip, and a support shaft 8 between the pressing body 9 and one of the support frames 4a. A biasing force to the left in the first drawing is applied by the spring IOK interposed therebetween, and normally the stopper 8a of the support shaft 8 is in contact with the left support frame 4a as shown in the first drawing. be. 11
is a control gear body for paper feeding which is spline-coupled to a portion of the rotating shaft 2 that protrudes outside the side plate 1, and includes a cylindrical portion 12, a partially toothed gear 13, a connecting portion 14 between the two gears 12 and 13, and a partially partially toothed gear. 13 and a pressed portion 15 located on the right side in the first drawing are formed integrally.

16 is a stopper 17 at the end of the rotating shaft 2 and a control gear body 11;
The control gear body 11 receives a biasing force in the right direction in FIG. It is in the state shown in the first diagram. When the carriage 4 moves to the left in FIG. 1, the pressing body 9 comes into contact with the pressed part 15 and presses it, and as a result of setting the force of the spring 10 to be larger than the force of the spring 16, the spring 16 is compressed, the control gear body 11 moves by a certain amount to the left in the figure, and the pushing body pressure 9
When the carriage 4 moves further at the time when it comes into contact with the side plate 1, the spring 10 is compressed and only the carriage 4 moves, resulting in K.

Reference numeral 18 denotes a toothless gear body rotatably held by a support 19 implanted in the side plate 1, and a toothless part 18a-1 is provided on a part of the outer periphery of the gear body.
A partially toothed gear 18a and a spur gear 18 connected thereto.
b are integrally provided (see Figs. 2 to 4). Further, the cylindrical portion 12 of the control gear body 11 has a circular shape.
An outer circumferential surface 12a and a second outer circumferential surface 12b having a fan-shaped outer circumferential surface 12b-1 and a small-diameter outer circumferential surface 12b-2 having the same diameter as the first outer circumferential surface 12a are provided (see FIGS. 2 and 3). figure(
a)), when the control gear body 11 is not pressed by the pressing body 9, the first outer peripheral surface 12a of the cylindrical portion 12
μ As shown in each (a)K of Fig. 2.3, the toothless gear body 18
The toothless gear body 18 is held unrotatably by being fitted into the toothless portion 18a-1. Further, as shown in FIG. 3(a), when the fan-shaped outer circumferential surface 12b-1 of the second outer circumferential surface 12b of the cylindrical portion 12 matches the toothless portion 18a-1, the control gear body 11
The toothless portion 13a of the toothless gear 13 is in the positional relationship shown in FIG. 3(b). Then, as the carriage 4 moves from the state shown in FIG. 2(a), the control gear body 11 is pressed and the first
If you move to the left in the figure by a certain amount of rotation, as shown in Figure 2 (
As shown in b), the first outer peripheral surface 12 of the cylindrical portion 12
When a is extracted from the toothless portion 18, a-1 of the toothless gear body 18, the toothless gear 13 reaches a position where it can mesh with the spur gear 1'8b of the toothless gear body 18, and the following carriage 4 in the same direction, that is, the rotation of the rotating shaft 2, the control gear body 11 further rotates in the same direction, and the second
The fan-shaped outer circumferential surface 12b-1 of the outer circumferential surface 12b is the helical gear body 18.
The tooth portion of the helical gear 13 meshes with the spur gear 18b of the toothless gear body 18 at the time of extraction from the toothless portion 18a-1.

In FIG. 1.4, reference numeral 20 denotes a ratchet body rotatably held by the support 19, which includes a ratchet 2 and a spur gear 22.
, and a cylindrical portion 23. The root portion of an elastic claw 24.24 is fixed to the cylindrical portion 23, and the claw 24.24 has an elastic claw 24.24.
The distal end thereof engages with a tooth portion of an inner ratchet 18C formed on the side surface of the partially toothed gear body 18. In addition, this inner ratchet 18c and the above-mentioned 2 chets 21 are recessed with their inclinations reversed. The prevention claw 25 is engaged. Therefore, the inner surface 2) 18
c (that is, the toothless gear body is) is shown in FIG. 4(b) in the direction of the arrow (
When the ratchet 21 is rotated in the clockwise direction, the rotation of the ratchet 21 is blocked by the return prevention pawl 25, so that only the partially toothed gear body 18 rotates, and the teeth of the inner ratchet 18c engage with the pawl 24. .24 is sequentially elastically deformed to overcome the problem, and the rotation of the partially toothed gear body 18 is not transmitted to the ratchet body 18. In addition, on the contrary, the toothless gear body 18 is
When rotating counterclockwise in Figure (b), the ratchet 21 is allowed to rotate in this direction, and the pawls 24 and 24 that engage with the inner ratchet 18c cannot be elastically deformed. As a result, the partially toothed gear body 18 and the double-channeled gear body 20 are designed to rotate together. In this embodiment, the rotation of the pulse motor 3 when the one-way clutch configured as described above is OFF and the one-way clutch is ON is used as the forward rotation direction to move the carriage 4 from the first fixed position to the right. are doing.

The spur gear 22 of the ratchet body 20 also includes a gear 2 of a paper feed shaft 26 rotatably held between the side plates 1.1.
7 are in mesh with each other, and as the spur gear 22 rotates, the paper feed shaft 2
6 rotates the paper feed roller 2 attached to the shaft 26.
8 is adapted to transport the paper.

In FIG. 5, reference numeral 29 denotes a cam body attached to the support shaft 8 provided on the carriage 4, which is given a rotational force in the direction of the arrow in the figure (clockwise direction) by a spring (not shown), and one end 29a of the cam body is attached to the support shaft 8 provided on the carriage 4. The guide plates 3o are always in contact with the upper surfaces of guide plates 3o formed in the entire transfer area of the carriage 4. As shown in FIG. 6, the guide plate 3o includes a high part 30'a, a low part 30b, and an inclined part 3 formed between both 30a and 30b.
0C, and in the movement area of the carriage 4 where the printing pad 5 prints, one end 29a of the cam body 29 comes into contact with the high part 30a of the guide plate 3o, and the cam body 29
is lifted counterclockwise in FIG. 5 against a spring (not shown), and the carriage 4 is rotated counterclockwise in the same figure about the rotating shaft 2, and printing is performed through the deflected spring force. The head 5 is pressed against the platen 32 via the paper 31. Further, the carriage 4 is transferred to the one end 2 of the cam body 29.
9a reaches the lower part 30bK from the inclined part 30c of the guide plate 30, the cam body 29 is rotated by the spring in the clockwise rotation direction in FIG.
is pressed down, the carriage 4 is rotated clockwise about the rotating shaft 2, and the print head 5 is separated from the paper 31.

Although it is generally clear from the above-described configuration, the operation of this embodiment will be explained next.

When the carriage 4 is now at the printing start position (initial position) for one line shown by Po in FIG. The fifth point where the head 5 came into contact with the paper 31
It is in the state shown.

Also, at this time, the carriage 4 is at a position on the right side of the drawing in which the suppressing body 9 is slightly spaced apart from the control gear body 11 in FIG. In this state, the first outer circumferential surface 12a of the cylindrical portion 12 of the control gear body 11 is connected to the toothless portion 18'a- of the toothless gear body 18.
Therefore, the partially toothed gear body 18 is unable to rotate regardless of whether the control gear body 11 rotates forward or reverse.

From this state, when the pulse motor 3 rotates forward based on the print start command, the screw unit 6 on the rotating shaft 2 rotates and begins to move the carriage 4 to the right in FIG. is driven to sequentially record desired print data at predetermined positions on the paper 31. Then, at position P+ (see FIG. 6) where one line of printing is completed, the pulse motor 3 rotates in reverse, and as the screw unit 6 rotates in reverse, the carriage 4 is moved to the left in FIG. 1 and returns to the initial position P. to return to. In addition, in FIG. 6, the printing stroke is shown as being a fixed distance, but this distance is arbitrary, and the speed is controlled to be faster during the return stroke than the printing stroke.

When the carriage 4 is moved in the same direction past the initial position: l 7 P 6 due to the reverse rotation of the pulse motor 3, the cam body 29 of the carriage 4 moves toward the guide plate 30.
As described above, the print head 5 separates from the paper 31, and the cam body 29 contacts the guide plate 30c.
The separating stroke of the print head 5 ends at a position P2 (see FIG. 6) where the print head 5 abuts against the lower portion 30b of the print head 5. At this position P2, the suppressor 9 of the carriage 4 comes into contact with the pressed portion 15 of the control gear body 11 (see FIG. 1), and by the subsequent reverse rotation of the pulse motor 3, the carriage 4 is moved to the left in FIG. direction, and accordingly, the control gear body 11 is moved by a certain amount to the left in the figure. Therefore, as described above, the first circumferential portion 12a of the cylindrical portion 12 of the control gear body 11 is
The state shown in FIG. 2(b) is obtained when the tooth is extracted from the missing tooth portion 18a-1 of No.8. When the control gear body 11 is moved to the left and the carriage 4 is further moved to the left while compressing the spring 10 described above, the control gear body 11 splined to the rotating shaft 2 is also moved. Naturally, it is rotating, and at the time when the fan-shaped outer circumferential surface 12b-1 of the control gear body 11 is extracted from the toothless part 18a-1 of the toothless gear body 18, the tooth part of the toothless gear 13 of the control gear body 11 meshes with the spur gear 18b of the partially toothed gear body 18, but as mentioned above, the one-way clutch prevents the rotation of the partially toothed gear body 18 from being transmitted to the ratchet body 20 when the pulse motor 3 is reversed. It has become.

In this way, the rotation of the pulse motor 3 when the carriage 4 moves to the left is not transmitted to the ratchet body 20 and paper feeding is not performed, so the carriage 4 moves by an amount corresponding to a predetermined paper feeding pitch. In other words, in this embodiment, the amount corresponding to the first, second, or third pitch shown in FIG. 6 is transferred from P2. Although optional, for example, the first, second,
The paper feed pitch corresponding to the third carriage feed pitch is set to 1/18 inch, 179 inch, 1/6 inch, etc. Further, the paper feed amount determination process shown in FIG. The movement to can be set at any time during the process of determining the paper feed amount. ) As described above, when the carriage 4 is moved by a distance corresponding to the predetermined paper feeding pitch, the pulse motor 3 immediately starts rotating in the normal direction, and this rotation causes the missing tooth of the control gear body 11 to rotate. Rotation is transmitted from the gear 13 to the partially toothed gear body 18, and the rotation is transmitted from the one-sided clutch to the gear 27 of the paper feed shaft 26 by the ratchet body 20 to feed the paper. At this time, the toothless gear body 18 has its toothless portion 18
The first part of the cylindrical part 12 in the control gear body xxi in a-1
Rotation is allowed until the circumferential surface 12a is fitted, in other words, until the carriage 4 is released from being pressed by the pressing member 9 and returns to the state shown in the first diagram, and the carriage 40 is moved in the process of determining the paper feed amount. The paper is rotated by an amount corresponding to the amount of rotation, that is, the amount of reverse rotation of the pulse motor 3 in the stroke, and the paper is fed by an amount corresponding to the selected pitch.

After paper feeding is completed, the pulse motor 3 rotates forward,
Head crimping is performed from Pv to Po, and the carriage 4 is at the initial position P.

The process returns to step 1 and prepares for the next print command for one line.

Although the configuration and operation of the embodiment are as described above, various modifications can be made without departing from the technical idea of the present invention. The paper may be fed during the reverse direction transport in step 4.

(Effects of the Invention) As described in detail above, according to the present invention, in a configuration in which a single motor is used to transport the carriage and feed the paper, it is possible to vary the transport pitch of the paper, and to Since the paper feed pitch is varied according to the amount of paper conveyed to the area, there is no need for an electromagnetic clutch to stop the carriage conveyance when paper is conveyed, and the paper conveyance device has a relatively simple mechanism and high operational reliability. Can be provided.

Furthermore, if an intermittent gear (sliding and rotation of an intermittent gear train) mechanism is used as in the embodiment, there will be no paper feeding when unnecessary, and a paper feeding device with stable feeding amount and good transient response can be provided. can.

[Brief explanation of the drawing]

The drawings all relate to a paper feeding device of a serial printer according to an embodiment of the present invention, and FIG. 1 is a plan view of the main part, and FIG.
a), (b) and Fig. 3 (a), (b) are explanatory diagrams of the intermittent gear mechanism, Fig. 4 (a), (b) are explanatory diagrams of the one-way clutch, and Fig. 5 is a side view showing the carriage. 6 are explanatory diagrams showing the relationship between carriage movement, paper feeding operation, etc. 2... Old private mail 3... Pulse motor 4... Carriage 5... Print head 6... Screw integrated 7... - Rack body 8... Support shaft 9... Suppression body 10... Spring 11... Control gear body 12... Cylindrical portion 12a. ...First outer circumferential surface 12b... Second outer circumferential surface 13 ... Gear with missing teeth 15 ... Pressed part 16 ... Spring 18 ... ... Gear body with missing teeth 18a... Gear with missing teeth 18a-1.... Missing tooth portion 18b... Spur gear 1 '8 c... Inner ratchet 20...
... Ratchet body 21 ... Ratchet 22 ... Spur gear 23 ... Cylindrical portion 24 ... Pawl 25 ... Return prevention pawl 26 ... Paper feed shaft 27 ... Gear 28 ... Paper feed roller 29 ... Cam body 30 ... Guide plate 31 ... ...Paper patent applicant Copal Co., Ltd.

Claims (1)

[Claims] A carriage that carries a print head and is transported in a direction perpendicular to the paper transport direction, a motor that rotates forward and backward to transport and drive the carriage in the forward and reverse directions, and a motor that rotates forward and backward to transport and drive the carriage in the forward and reverse directions, and a a paper feeding means that changes the paper feeding pitch according to the amount of paper conveyed to the printing area, and selectively transmits either forward rotation or reverse rotation of the motor when the carriage is outside the printing area. A paper feeding device for a serial printer characterized by: