JPS6236255A - Sheet-head adjustment for printing device - Google Patents

Abstract

PURPOSE:To correctly adjust the head part of the sheet sent out from a feeding means by nipping said sheet between two transport means and discharging said sheet by reversely revolving the feeding means and then nipping said sheet again onto the transport means. CONSTITUTION:The edge part of a sheet P sent out one by one from a feeding roller 58 is nipped between a platen 19 and a pressure roller 33. Then, the sheet P is discharged through the reverse sending by reversely revolving the feeding roller 58 and the platen 19. The sheet P is curved as shown by the dotted line in the figure because of the peripheral speed difference between the feeding roller 58 and the platen 19, and the top edge of the sheet P uniformly contacts with the platen 19. Then, the sheet P is sent to a printing head 29 by normally revolving the platen 19 and the feeding roller 58, and the sheet P is temporarily brought into stop, and printing of one line is carried out, and then the operation for the next line is carried out. Therefore, the bending of the head part of the sheet P is prevented, and the sheet P is correctly resisted, and correct printing is performed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sheet cueing method for a printing device such as a printer or a typewriter, in which a sheet such as printing paper is set at the printing position of the printing device.

[Technical background of the invention]

Generally, when printing on a plurality of sheets of paper continuously using a printing device such as a printer or a typewriter, a paper feed unit that automatically supplies the paper is attached to the paper feed port of the printing unit.

Some paper feeding units are equipped with a drive source, but
Recently, in order to reduce costs, some printers do not have a driving source, but instead obtain driving force from a printing unit to rotate a paper feed roller and feed sheets one by one to the printing unit.

Further, the printing unit grips the supplied paper between a platen and a pressure roller, supplies it to a printing position, and prints with a head that reciprocates along the platen.

An example of a printing device in which the driving force for the paper feed unit is obtained from the printing unit in this manner is disclosed in Japanese Patent Publication No. 58-6633.

In order to register the leading edge of the paper sent out by the paper feed roller, this printing device bends the paper by abutting the leading edge of the paper against the pressure contact between the platen and the pressure roller, and uses the stiffness of the paper to register the leading edge of the paper. are doing.

However, since the paper feed unit receives driving force from the print unit, when the paper feed roller is rotating, the platen must also rotate. On the other hand, in order to register the leading edge of the paper sent out by the paper feed roller, if the platen is rotated in the conveyance direction of the paper, the leading edge of the paper cannot be registered. For this reason, the platen is rotated in a direction opposite to the paper conveyance direction.

In other words, the paper sent out by the paper feed roller is brought into contact with the pressure roller between the platen and the pressure roller, which rotates in the opposite direction to the conveyance direction, and the paper is deflected to register the leading edge of the paper.Then, the platen is rotated in the normal direction. the paper is set in the print position.

[Problems with background technology]

However, because the paper is in contact with the press between the platen and the pressure roller, which rotate in the opposite direction to the conveyance direction,
Not only is the leading edge of the paper bounced and not registered accurately, but the leading edge of the paper is easily bent.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet cueing method for a printing device in which the leading edge of the paper is not easily bent during registration and can accurately register the leading edge of the paper.

[Summary of the invention]

In order to achieve the above object, the present invention grips a sheet sent out by a feeding means such as a paper feed roller between a first conveying means such as a platen and a second conveying means such as a pressure roller. After that, the sheet is once retracted and discharged while the feeding means is reversely fed, and then the sheet is again held between the first conveying means and the second conveying means and moved to the printing position. It was designed to be sent to.

[Embodiments of the invention]

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

The printing device of this embodiment includes a printing unit 3 as shown in FIGS. 1 and 2 and a paper feeding unit 1 as shown in FIG.
01.

First, the printing unit 3 has a structure as shown in FIGS. 1 to 4.

As shown in FIG. 1, a frame 9 is provided inside the cover 7 of the printing unit 3, and a platen shaft 13 is rotatably supported on both sides 9L, 9R of the frame 9 via bearings ILL, 11R. A platen knob 15L and a gear 17 are placed on the left side of the platen shaft 13, and a platen 1 is placed in the center.
9 is attached, and a gear 21 and a platen knob 15R are attached to the right side.

Further, a motor 23 for driving the platen 19 is attached to the side portion 9R of the frame 9, and the driving force of this motor 23 is transmitted to the gear 21 via gears 24 and 25.

Furthermore, as shown in FIG. 2, guide rods 26, 28 are provided parallel to the platen 19. A head carriage 27 is attached to these guide rods 26, 28 so as to be able to reciprocate, and the head carriage 27 is driven laterally along the guide rods 26, 28 by a drive device (not shown). .

The print head 2 is mounted on the head carriage 27 as shown in FIG.
9. A tip guide 30 is attached, and a ribbon cassette 34 is detachable.

Further, as shown in FIGS. 2 and 3, around the platen 19, there are pressure rollers 33, 35 arranged in two rows of platen guides 31, a paper pail roller 37 that presses the paper against the platen 19, a platen cover 39, etc. is provided.

The pressure rollers 33, 35 are constructed by rotating the pressure lever 43 shown in FIGS. 1 and 3 about the shaft 42, so that the roller 44 turns the arm 46 attached to the shaft 45, The guide 31 rotates around the platen 19 and is brought into or out of pressure contact with the platen 19. Note that the arm 46 is urged against the roller 44 by a spring 48.

The material paper bail roller 37 is connected to the paper bail lever 4
By rotating the arm 51, the arm 51 is rotated about the shaft 49, and the arm 51 is brought into or out of pressure contact with the platen 19.

Note that a cover 53 can be opened and closed above the head carriage 27, and the ribbon cassette 34 can be replaced in the open state.

The paper feed/discharge port 5 of the printing unit 3 configured as described above has a paper feed unit 1 as shown in FIGS.
01 is installed.

As shown in FIG. 8, this paper feeding unit 101 supports a paper feed stacker 54 that accommodates stacked sheets of paper P by a pair of left and right side plates 56L and 56R as shown in FIG. The paper P is sent out to the platen 19 side.

The side plate 56L has a housing portion 57 and a flange 59 as shown in FIG.
, a support portion 61 of a support shaft 65 that supports the paper feed stacker 54
It is equipped with such things as

Further, as shown in FIG. 9, the housing portion 57 includes a shaft hole 69 that supports a rotating shaft 67 to which a paper feed roller 58 is attached, and a support shaft that supports a manual feed guide 71 provided in front of the paper feed roller 58 from above and below. A shaft hole 77.79 is provided which holds 73.75. Although not shown, a confirmation window for confirming the home position of the drive transmission mechanism 55 of the paper feed roller 58 is provided.

A drive transmission mechanism 55 is housed in the housing portion 57, as shown in FIGS. 9 and 10.

First, a gear 107 that meshes with the gear 17 of the printing unit 3 is attached to the support shaft 81 .

Further, a gear 109 that meshes with the gear 107 is attached to the rotary shaft 108 to which the paper discharge roller 241 is attached, and a gear 111 that meshes with the gear 109 and a gear 113 smaller than the gear 111 are attached to the support shaft 85. Furthermore, the support shaft 87
A gear 115 that meshes with the gear 113 is attached to the support shaft 89, and a gear 119 that meshes with the gear 115 is attached to the support shaft 89.

A ratchet pawl 123 rotating about a shaft 121 and a leaf spring 125 biasing the ratchet pawl 123 toward the support shaft 89 are attached to the inside of the gear 119. A cam 127 that regulates the operation of the ratchet pawl 123
are attached to pins 91.93.95. Note that a color indicating the home position is displayed at one location on the outside of the gear 119 at a position corresponding to the confirmation window.

Furthermore, a gear 129 shown in FIG. 10 is attached to the support shaft 89. A check 131 shown in FIG. 9 is attached to the gear 119 side of this gear 129. Shaft hole 6
9 is a gear 1 that meshes with a gear 129 via a support shaft 67.
There are 33 locations.

The drive five-speed mechanism 55 configured in this way is covered with a cover plate 147 as shown in FIG. Note that this drive transmission mechanism 55 changes the paper feeding speed of the platen 19 to vl,
If the paper feeding speed of the paper feeding roller 58 is V2, V1. ＞
The gear ratio was set so that V2.

A chucking portion 99 is attached below the accommodating portion 57 that accommodates the drive transmission mechanism 55, as shown in FIG. This chucking portion 99 includes a fitting portion 135 that fits into the bearing 11L shown in FIG.

On the other hand, the side plate 56 includes a flange 165, support parts 169, 171, 173, and a chucking part (not shown) similar to the chucking part 99 that fits with the bearing 11R in FIG. 1, as shown in FIG. There is.

A support shaft 65.73.75 and a conveyance guide 134 are attached between the side plates 56L and 56R configured as described above to provide rigidity and to provide rotation shaft 67.108.
is rotatably mounted.

The support shaft 65.75 has a bottom plate 1 having an N-shaped side surface.
95 are attached via support plates 197 and 199.

This bottom plate 195 includes a back surface section 195A located at the rear, a stopper section 195B that holds the leading edge of the paper, a guide section 195C that guides the paper forward, and a support section 19 shown in FIG.
It is equipped with 5D. A paper feed frame 201 that supports the rear of the paper on the paper feed stacker 54 is removably attached to the rear surface portion 195A.

Further, a set lever 202 that moves the paper feed stacker 54 up and down is rotatably attached to the support portion 195D via a shaft 204. This set lever 202 is a lever part 20
2A and a cam portion 202B are integrally provided. A click spring 206 is installed between the support portion 195D and the cam portion 202B.

A paper feed stacker 54 is rotatably attached to the support shaft 65. As shown in FIG. 8, this paper feed stacker 54 is divided into a left stacker 54L having a side plate 203L and a right stacker 54R having a side plate 203R. The left stacker 54L is fixed in the axial direction, and the right stacker 54R is movable in the axial direction.

The back side of the left stacker 54L has a pin 21 that engages with the cam portion 202B of the set lever 202, as shown in FIG.
A frame 213 is attached to the frame 213. The frame 213 has an arm 213L to which a spring 1 is attached and a spring attachment portion 213R shown in FIG. A spring 215 is attached between the spring attachment portion 213R and the back portion 195A,
The paper feed stacker 54 is always urged toward the paper feed roller 58 side.

A support shaft 217 is provided on the outside of the side play) 203L, 203R, and separation levers 219L, 219R are attached through attachment holes 221.

The separation levers 219L and 219R include a separation claw 223 that separates the paper P sent out by the paper feed roller 58 into one sheet, and a stopper 225 that restricts the amount of downward rotation.

Sponge rollers 227L and 227R are attached to both sides of the paper feed roller 58 on the rotation shaft 67 to which the paper feed roller 58 is attached.

The manual feed guide 71 supported by the support shafts 73 and 75 has arms 229L, 229L and 229L, which engage with the support shaft 75 on both lower sides.
29R, and a paper discharge frame 233 is attached to the upper part via a pair of support parts 231. Note that this paper ejection frame 233 constitutes a paper ejection stacker together with the recessed portion of the conveyance guide 134 and the manual feed guide 71.

The support part 231 has a slit 235 that engages with a notch provided in the upper part of the manual feed guide 71, and also has a stopper 237, and this stopper 237 and the manual feed guide 71
A leaf spring 239 is interposed between the support part 2 and the back surface of the upper part.
31 is fixed to a manual feed guide 71, and the manual feed guide 71 is held on a support shaft 73.

A plurality of paper ejection rollers 241 are provided on the rotating shaft 108 as shown in FIGS. 5 and 8.

Further, the conveyance guide 134 forms a manual feed port 243 between it and the manual feed guide 71, and is formed in an N-shape so as to support the rear end of the paper P discharged by the paper discharge roller 241. Further, a static eliminating brush 245 is attached to the front surface of the conveyance guide 134 as shown in FIG.

The paper ejection guide 141 guides the paper P ejected from the printing unit 3 toward the paper ejection roller 241 side.
It has support plates 246L and 246R as shown in the figure, and is rotatably supported by side plates 56L and 56R about shafts 143 and 189.

The printing device configured as described above operates as follows.

First, rotate the lever part 202A of the set lever 202 shown in FIG.
1 to move the paper feed stacker 54 away from the paper feed roller 58.

Then, the sheets P are stacked on this sheet feed stacker 54 with their leading ends abutting against the stopper portion 195B of the bottom plate 195. At this time, the right stacker 54R is moved according to the width of the paper P.

Next, turn the platen knob 15L by hand while looking through the confirmation window provided on the side plate 56L, stop when the color indicating the home position is visible, and set the platen to the home position.

Then, the lever portion 202A is rotated clockwise as shown by the solid line in FIG. 6 to remove the cam portion 202B from the pin 211. As a result, the return force of the spring 215 causes the paper feed stacker 5 to
4 is urged upward, and the paper P is pressed against the paper feed roller 58.

In this state, when a print command is issued, the helad carriage 27 shown in FIG. 4 moves from the left end home position to the center side and waits for paper to be supplied.

Further, the motor 23 in FIG. 1 is driven to rotate as shown in FIG. 11, and the platen shaft 13 rotates clockwise in FIGS. 9 and 10.

For two, gear 17.107.109.111.113
．． Gear 119 rotates to the left via gear 115. At this time, the ratchet pawl 123 is in contact with the inner circumferential surface of the cam 127, so it is not coupled to the ratchet 131. Therefore, the gear 129 does not rotate and the drive is not transmitted to the rotating shaft 67, so the paper feed roller 58 does not rotate.

As the gear 119 rotates, the ratchet pawl 123 engages the cam 1.
When it comes off from 27, it engages with ratchet 131. Therefore, the driving force of the gear 119 is transmitted to the gear 129, the paper feed roller 58, the sponge roller 227L, and the second roller 22 as shown in FIG.
The paper P is pushed out by the paper feed roller 58 while being lightly pressed by the paper feed rollers 7L and 227R.

At this time, both front ends of the paper P are caught by the separation claws 223 and 223 and begin to bend. Then sponge roller 2
27L and 227R are deformed by the force caused by the bending of the paper. When the deflection of the paper exceeds the elastic limit, both front ends of the paper P bounce and are separated into one sheet, which passes between the guide section 195C and the manual feed guide 71 and is fed between the platen 19 and the pressure roller 33. .

After the motor 23 starts rotating, the rotation of the motor 23 is stopped when it has rotated a predetermined amount M1 as shown in FIG. 11, that is, when the platen 19 and the pressure roller 33 have gripped the paper as shown in FIG. .

Then, the motor 23 is reversely rotated by a predetermined amount M2. As a result, the platen 19 rotates in reverse and discharges the paper P.

By the way, since the gear 119 also rotates in the opposite direction due to the reverse rotation of the platen shaft 13, the ratchet 131 and the ratchet pawl 123
The gear 129 also rotates in the opposite direction due to the engagement with the paper feed roller 58.
and the sponge roller rotates in the opposite direction.

At this time, as shown in FIG. 12, the paper feed speed ■1 when the platen 19 is reversed is greater than the paper feed speed V2 when the paper feed roller 58 is reversed, so the paper P is The leading edge of the paper P is also deflected between the platen 19 and the paper feed roller 58 and is registered between the platen 19 and the pressure roller 33 due to the stiffness of the paper P.

Then, when the platen 19 rotates normally again, the paper P is gripped by the platen 19 and the pressure roller 33, and the paper P is backed up and fed by the paper feed roller 58 at the rear.

When the gear 119 rotates further and the ratchet pawl 123 comes into contact with the inner peripheral surface of the cam 127, the ratchet pawl 1
23 is removed from the ratchet 131, and the drive is no longer transmitted to the gear 129.

However, the paper P is connected to the platen 19 and the pressure roller 33.
．． 35, so the platen 19
The paper P is pulled by the rotation of the paper P. Therefore, the paper feed roller 58 and the sponge rollers 227L and 227R rotate following the paper P.

When the motor 23 has rotated a predetermined amount M33, that is, at the printing start position of the paper P, the motor 23 is temporarily stopped, and the print head 29, which was located on the center side, is returned to the home position on the left side by the movement of the carriage 27. Start printing. - motor 23 every time printing of each line is completed.
rotates one line at a time.

The printed paper P is guided along the guide portion of the paper ejection guide 141 and is ejected by the paper ejection roller 241. The leading edge of the ejected paper is in contact with the manual feed guide 71 and the paper ejection frame 233, and the trailing end is in contact with the transport guide 133.
It is supported in the recess of.

In the case of continuous paper feeding, the above operation is repeated, and the paper P is sent out in a constant cycle regardless of the length.

According to the above embodiment, the following effects can be obtained.

(1) After the paper sent out by the paper feed roller 58 is held between the platen and the pressure roller 33,
Since this paper is once retreated and discharged while reversing the paper feed roller 58, when the paper is gripped, the platen 19 and pressure roller 33 rotating in the conveying direction
Since the paper is supplied to the pressure contact portion with the paper, the paper is smoothly gripped and the leading edge of the paper is not easily bent.

(2) When the paper held between the platen 19 and the pressure roller 33 is temporarily moved backward by the reverse rotation of the platen 19 and then discharged, the paper feed roller 58 is also reversed by a backward movement amount that is smaller than the movement of the platen 19. So,
Even if the amount of paper held between the platen 19 and the pressure roller 33 is large, the amount of deflection of the paper formed by reversing the platen 19 is small.

That is, when feeding paper, the paper feed roller 58 and the paper may slip and the paper may not reach the platen 19.
Even if the amount of paper P to be held between the paper feed roller 5 and the pressure roller 33 is set large, the paper P that has been held between the paper feed roller 5 and the pressure roller 33 is
8 is reversed while retreating and spitting out,
The amount of paper deflection is smaller than the amount of grip.

Therefore, there is no need to provide a large space for deflecting the paper, and the leading edge of the paper can be reliably registered even though the amount of deflection is small.

Further, the sheets discharged by the paper discharge roller 241 have little curl, and can be stored in the paper discharge stacker in good alignment.

(3) After the motor 23 has rotated by a predetermined amount M1 after the motor 23 starts rotating, the motor 23 is rotated in the opposite direction to register the paper P, so that the paper can be ejected without the need for a paper edge detection means such as a sensor; Regis l~ can be done.

Therefore, this cueing method can be applied even to a printing device in which the printing unit 3 is not provided with a sensor for detecting the leading edge of the paper held between the platen 19 and the pressure roller 33.

That is, cueing can be performed without depending on the format of the printing unit 3.

[Modified example]

The present invention is not limited to the above-mentioned embodiment, and for example, the following modifications are possible.

(1) In the above embodiment, a printing device is shown in which the printing unit and the paper feeding unit are detachable, but the printing unit and the paper feeding unit may be integrated.

(2) In the above embodiment, after the platen 19 rotates and feeds the paper by the paper feed roller 58, the motor 23 is rotated by a predetermined amount M2 after rotating by a predetermined amount M1, and the pressure roller 33 is rotated by a predetermined amount M2.
Although the sheet held by the platen 19 is ejected, a sensor may be provided at the tip of the pressure roller 33, and when this sensor detects the leading edge of the sheet, the platen 19 may be reversed.

(3) As shown in FIG. 13, the paper conveyed along the guide 301 is moved by two or more pressure rollers 303.
305 and 307 may be pressed against the platen 309.

In this case, once the paper has been held up to the pressure roller 305, the paper may be moved backward and discharged, or when the paper has been held up to the pressure roller 307, it may be discharged.

(4) In the above embodiment, the platen 19 is driven and the pressure rollers 33.35 are driven, but the pressure rollers 303, 305, 307 may be driven and the platen 309 is driven as shown in FIG. .

Also, the platen 309 and pressure rollers 303 and 305
．． 307.

(5) This invention is based on the platen 311 as shown in FIG.
is fixed, and the present invention can also be applied to a printing device in which paper guided by a guide 313 is fed to a printing position by rollers 315, 317, 319, and 321.

(6) This invention provides a guide 323 as shown in FIG.
The paper guided by 325 is transferred to rollers 327 and 329.
It can also be applied to a printing device that supplies the printing position of the platen 335 by 331.333.

〔Effect of the invention〕

As explained above, according to the present invention, the stacked sheets are fed out one by one by the feeding means, and the fed sheets are held between the first conveying means and the second conveying means which are pressed together. In a printing device that performs printing work by feeding the sheet to a printing position, the sheet fed by the feeding means is held between the first conveying means and the second conveying means, and then The sheet is once retracted and discharged while the feeding means is reversely fed, and then the sheet is again held between the first conveying means and the second conveying means and sent to the printing position. , the leading edge of the paper is hard to break during registration, and the leading edge of the paper can be accurately registered.
You can get a cue method.

[Brief explanation of drawings]

Figures 1 to 4 are diagrams showing the configuration of the printing unit l-, in which Figure 1 is a cross-sectional view of the printing unit, Figure 2 is a longitudinal sectional view of the printing unit, and Figure 3 is the pressure roller pressure contact mechanism. FIG. 4 is a cross-sectional view showing the structure around the print head. Figures 5 to 10 are diagrams showing the configuration of the paper feed unit, where Figure 5 is a vertical sectional view showing the overall configuration of the paper feed unit, Figure 6 is a left side view of the area around the paper feed stacker, and Figure 7 is a diagram showing the structure of the paper feed unit. 8 is a right side view of the vicinity of the paper feed stacker, FIG. 8 is a partially cutaway plan view of the paper feed unit, and FIGS. 9 and 10 are diagrams showing the structure of the drive transmission mechanism. Figure 11 is a timing chart 1- for explaining the operation.
1 FIG. 12 is an explanatory diagram of the operation. FIGS. 13 to 15 are diagrams showing modifications of the present invention. 3... Printing unit 19... Platen 2
9...Print head 33, 35...Pressure roller 101...
・Paper feed unit 58...Paper feed roller 241...
...Sheet ejection roller information Fig. 30.5'' No. 13/10 Fig. Jl y j 15

Claims (6)

[Claims] (1) The stacked sheets are sent out one by one by a feeding means, and the sent out sheets are held between a first conveying means and a second conveying means that are pressed together and sent to a printing position, In a printing device that performs a printing operation, after the sheet sent out by the feeding means is held between the first conveying means and the second conveying means, the sheet is reversely fed by the feeding means. The sheet head of the printing device is characterized in that the sheet is once retreated and discharged while the sheet is moving, and then the sheet is again held between the first conveying means and the second conveying means and sent to the printing position. How to put it out. (2) In the sheet cueing method for a printing device according to claim 1, the first conveyance means is a platen, and the second conveyance means is a pressure roller. How to cue the sheet. (3) In the sheet cueing method for a printing device according to claim 1, the first conveying means and the second conveying means are rollers that are pressed against each other. How to cue the sheet. (4) In the sheet cueing method for a printing device according to claim 1, the first conveying means is driven by a drive source, and the second conveying means is driven by the operation of the first conveying means. A sheet cueing method for a printing device characterized by being driven. (5) In the sheet cueing method for a printing device according to claim 1, the second conveying means is driven by a drive source, and the first conveying means is driven by the operation of the second conveying means. A sheet cueing method for a printing device characterized by being driven. (6) In the sheet cueing method for a printing device according to claim 1, the sheet held between the first conveyance means and the second conveyance means is once retreated and then discharged. A sheet cueing method for a printing device, characterized in that the speed is faster than the speed at which the feeding means reversely feeds.