JPH02152823A - Automatic paper feeding device - Google Patents

Abstract

PURPOSE:To eliminate the restraining force to sheets on the paper feed unit side and in accordance with this, reduce the feed load of the sheets to the paper feed roller on the printer side by providing such a constitution as making a holding mechanism hold a pressure plate in a retarded position and separating laminated sheets on the pressure plate from the paper feed roller. CONSTITUTION:When a paper feed motor is positively rotated, this rotation is transmitted to paper feed rollers 24a, 24b through a rotation transmitting mechanism to rotate the paper feed rollers 24a, 24b, whereby sheets 10a on pressure plates 22a, 22b are sent one by one to the printer unit side. When the sheets are caught by paper feed rollers 8a, 8b of the printer unit, the paper feed motor is reversely rotated in a determined amount, and this rotation is transmitted to a rack opinion mechanism 27a through the rotation transmitting mechanism, whereby the pressure plates 22a 22b are retarded against a pressing means 23 to separate the laminated sheets 10A from the paper feed rollers, and at the same time, the retarding transmission of the pressure plates is held by a holding mechanism.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sheet-fed automatic paper feeder that separates stacked sheets of paper one by one and sends them to a printer, and in particular, relates to a sheet-fed automatic paper feeder that separates stacked sheets of paper one by one and sends them to a printer. The present invention relates to an automatic paper feeder applied to a flat type printer that prints while printing.

(Prior Art) Conventionally, a flat type printer is known from, for example, Japanese Utility Model Application Publication No. 63-66241.

This type of printer holds a platen placed opposite the print head in a fixed state, making the print head contact surface of the platen flat, and a pair of feed rollers are placed above and below the front and back of the platen. The front and rear feed rollers transport sheets of paper fed from an automatic paper feeder in a flat state over a platen, and print on the paper on the flat surface of the platen.

[Problem to be solved by the invention]

By the way, in the above-mentioned flat type printer, the print head contact surface of the platen is flat, so
It has the advantage that the outline of the print is clear and the paper does not curl up like a roll-type platen, but the paper feed rollers, which are placed in pairs at the front and back of the platen, are made of an elastic material such as synthetic rubber. However, since the upper and lower rollers are in contact only approximately tangentially, the paper feeding force is small, and if resistance is applied to the paper, it may slip and paper feeding becomes unstable, causing the printed line spacing to change. There is a problem that the numbers are not aligned.

In addition, in order to avoid the above-mentioned slip trouble, it is possible to increase the contact pressure between the upper and lower pair of rollers.
In this way, the driving force of the roller increases, requiring a motor with a larger driving force than a tangential contact type roller drive, and the roller support shaft and its support member are also made of strong material that will not easily deform. , which increases weight, size, and costs.

In addition, even if the leading edge of the sheet fed sheet-by-sheet from the automatic paper feeder to the printer is caught in the paper feed roller on the front stage of the printer, the trailing edge of the sheet is caught by the paper feed roller on the stacker side. Therefore, even if the paper feed roller on the stacker side rotates due to the conveyance operation by the paper feed roller on the printer side, the frictional resistance of the paper feed roller shaft bearing and the pressure on the paper feed roller cause the paper to move on the same floor. There is a problem in that the frictional resistance acts as a load on the paper feed roller on the printing side, causing trouble in paper feeding.

SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic paper feeding device that can solve the above-mentioned problems, reduce the paper feeding load on the printer side, and realize stable and reliable paper feeding.

[Means for Solving the Problems] The automatic paper feeder of the present invention includes a pressure plate that is supported by a stacker frame main body so as to be swingable in the front and rear directions and presses the stacked paper, and a pressure plate that is located in front of the pressure plate and that A paper feed roller rotatably supported by a frame body, a pressing means for pressing the stacked paper against the paper feed roller via the pressure plate, a paper feed motor attached to the frame body and capable of forward and reverse rotation; a rotation transmission mechanism that transmits the rotation of the paper feed motor to the paper feed roller when the paper feed motor rotates forward; a rack mechanism that moves the pressure plate forward and backward; and a rotation transmission mechanism that transmits the reverse rotation of the paper feed motor to the rack mechanism. The apparatus includes a rotation transmission mechanism that moves the pressure plate backward against the pressing means, and a holding mechanism that holds the pressure plate in the retreated position.

[Function] In the present invention, when the paper feed motor rotates forward, this rotation is transmitted to the paper feed roller via the rotation transmission mechanism, and by rotating the paper feed roller, one sheet of paper on the pressure plate is transferred. Send it to the printer unit side. Then, when the paper is caught in the paper feed roller of the printer unit,
The paper feed motor reversely rotates by a predetermined amount, and the rotation is transmitted to the rack and pinion mechanism via the rotation transmission mechanism, thereby causing the pressure plate to move backward against the pressing means, thereby separating the stacked paper from the paper feed roller. At the same time, the backward transmission of the pressure plate is held by the holding mechanism.

Therefore, in the present invention, when the printing unit side feeds paper, the binding force on the paper on the paper feeding unit side is removed, and the paper feeding load on the printing unit side is reduced.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a partially cutaway front view showing an example of an automatic paper feeder according to the present invention, and FIG. 2 is a partially cutaway front view of a flat printer equipped with the automatic paper feeder according to the present embodiment. FIG.

In the figure, 1 is a printer unit, and 2 is an automatic paper feeding unit that is removably set on the link unit 1.

As shown in FIG. 2, the printer unit 1 includes a printer main body 3 and a paper discharge stacker 4 that is removably set on the printer main body 3.

The printer main body 3 has a paper guide plate 5 arranged horizontally in the direction from the automatic paper feed unit 2 to the paper discharge stacker 4 at its upper part. A platen 6 is disposed perpendicular to the longitudinal direction of the paper guide plate 5, and a print head 7 is disposed above the platen 6. Also, platen 6
A pair of paper feed rollers 8a and 8b that feed the paper 10A sent from the automatic paper feed unit 2 toward the print head 7 are placed on the paper introduction end side of the paper guide plate 5 located at the front stage of the paper guide plate 5. Further, on the terminal end side of the paper guide plate 5 located after the platen 6, a pair of paper feed rollers 9a and 9b for feeding the printed paper to the paper ejection stacker 4 are arranged vertically in contact with each other. The front and rear paper feed rollers 8a, 8b and 9a, 9 are arranged.
b is rotationally driven by a motor (not shown).

The paper discharge stacker 4 includes a paper guide 11 that guides the printed paper 10B sent by the paper feed rollers 9a and 9b to the storage section 4a of the paper discharge stacker 4, and one end of this paper guide 11 is connected to the stacker frame. An operating lever 12 rotatably attached to the body 4b and protruding outside the stacker frame 4b.
This allows the paper guide 11 to be switched between the position shown by the solid line and the position shown by the two-dot chain line in FIG.
When is in the position shown by the solid line, the printed paper 10B is guided to the paper ejection stacker 4, and when it is in the position shown by the two-dot chain line, it is guided through the front paper ejection path 13 formed in the printer main body 3 to the print main body 3. It is designed to be discharged outside.

Reference numeral 14 denotes a paper ejection roller rotatably provided on the stacker frame 4b in close proximity to the pivot base of the paper guide 11.
By transmitting the rotation of the paper feed roller 9a to the paper discharge roller 14, the printed paper 10B guided through the paper guide 11 is transferred to the storage section 4a. It is designed to be sent to

Next, the automatic paper feeding unit 2 will be described.

As shown in FIGS. 1 and 2, the automatic paper feeding unit 2 includes a frame main body 17 that is detachably set on the printer unit 1, and a paper feeding unit that accommodates unprinted paper 10A stacked in an inclined state. A stacker 18 is provided.

The paper feed stacker 18 has left and right side plates 17a and 17b that constitute the frame body 17, as shown in FIGS. 1 and 10.
A guide rod 19 and a guide bar 20 are horizontally fixed in between.
It has its own support plates 21a, 21b which are movably supported along the longitudinal direction thereof, and pressure plates 22a, 22b which are attached to the upper ends of each of these support plates 21a, 21b so as to be movable in the front and back direction. pressure plate 2
2a and 22b are pressure springs 23 interposed between their swinging lower ends and the respective support plates 21a and 21b facing thereto.
is constantly urged forward by the pressure plate 22
The sheets IOA stacked and stored in the sheets IOA a and 22b are pressed against sheet feed rollers 24a and 24b, which will be described later, and the swinging ends of the pressure plates 22a and 22b are provided with holes that pass horizontally through the pressure plates 22a and 22b horizontally. A pressure plate shaft 25 is attached, and both ends thereof are connected to the left and right side plates 17.
It protrudes out of the side plate through the elongated guide holes 26a and 26b (see Figs. 1 and 4) formed in the guide holes 26a and 17b, and pinions 27a and 27b (see Figs. 1 and 4) are attached to the protruding ends. is fixed.

The paper feed rollers 24a, 24b have left and right side plates 17a,
It is attached to a roller shaft 28 (see FIG. 1) which is rotatably suspended horizontally between the roller shafts 17b and 17b so as to be movable only in the axial direction. A gear 29e constituting the gear train is attached via a one-way bearing 30 that transmits rotation in only one direction.

In Figures 1 to 3, 31 is the pressure plate 2.
This paper feed motor 31 is fixed to a support plate 33 attached parallel to the right side plate 17a by a plurality of supports 32, and is mounted on the inside of the support plate 33. A drive gear 34 is fixed to the rotating shaft of the paper feed motor 31 that protrudes toward the paper feed motor 31 . Further, a paper feed roller 24 is provided on the inner surface of the support plate 33 as shown in FIGS. 4 and 5.
a.

Gears 29a to 2 forming a gear train for transmitting rotation to 24b
9d is rotatably attached to the shaft, and gear 2 of this gear train
9a is engaged with the drive gear 34, and the gear 29d is connected to the one-way bearing 3 on the paper feed roller shaft 28 as shown in FIG.
It is meshed with a gear 29e attached via 0.

Further, the gear train for reversing the pressure plates 22a and 22b consists of gears 35a to 35d, of which the gear 35a meshing with the drive gear 34 and the gear 35b coaxial therewith are rotatably supported on the support plate 33. The gear 35c that meshes with the gear 35b is rotatably supported on the right side plate 17b, and the gear 35d that meshes with the gear 35c is supported on a shaft supported on the right side plate 17b as shown in FIG. It is fixed to the outer ring of a one-way hair ring 37 fitted in the section 36. Further, a shaft 38 is fitted into the inner ring of the one-way bearing 37, one end of which is supported by the shaft bearing part 36, and the other end has a shaft 38 extending 180 mm in the circumferential direction.
A pawl mold 39 having notches 39a and 39b with a phase difference of 100 degrees is fixed to the boss portion of the pawl mold 39.
0 is formed. A tension spring 41 is placed between the outer peripheral edge of the pawl mold 39 and the support plate 33 for returning the position of the toothed gear 40 in the circumferential direction to the reference point, and furthermore, on the right side plate 17b, A pawl is provided that prevents the pawl mold 39 from reversing by engaging with the notch 39a or 39b. That is, a claw 42 that holds the pressure plates 22a, 22b in the retracted position is rotatably attached to the stand 43, and this claw 42 is urged by a torsion spring 44 in a direction to constantly engage with the notch 39a or 39b. There is.

In FIGS. 1, 3 to 5, and 8, the movable rack plate 45 for retracting the pressure plate is located on the right side plate 1.
A sliding groove 45 is disposed above the elongated hole 26b for guiding the pressure plate shaft on the surface facing the support plate 33 of the movable rank plate 45, and is formed in the longitudinal direction of the movable rank plate 45.
A is slidably supported in the longitudinal direction of the elongated hole 26b by engaging with a guide protrusion 46 protruding from the right side plate 17b, and furthermore, rack teeth 45a formed on the upper edge of the movable rack plate 45 is a toothed gear 4 formed on the boss portion of the claw mold 39.
The rack teeth 45b formed on the lower edge of the pressure plate shaft 25 are designed to intermittently mesh with the pressure plate shaft 25.
It is meshed with a pinion 27b fixed to. Further, a fixed rack 47 located below the elongated hole 26b and provided along the elongated hole 26b on the right side plate 17b is engaged with the pinion 27b from below. Furthermore, a fixed rack 48 is provided along the elongated hole 26a on the left side plate 7a, located below the elongated hole 26a for guiding the pressure plate shaft.
A pinion 27a fixed to is engaged with the pinion 27a.

In FIG. 2, 49 is the front paper feed roller 8a, 8b.
A sensor 50 is arranged close to the paper feeding rollers 8a, 8 to feed the paper 10B fed from the automatic paper feeding unit 2.
51 is a paper guide path that guides the paper to the space between b and 51 is a release lever of the pressure plate.

Next, the operation of this embodiment configured as described above will be explained in the 10th section.
This will be explained with reference to FIGS. 16 to 16.

First, before paper feeding to the printer unit l-1 starts, the pressure plates 22a and 22b are pressed against the paper feed rollers 24a and 2 by the pressure spring 23, as shown in FIG.
4b direction, and as a result, the pressure plate 2
The entire stack of sheets 10A set on sheets 2a and 22b is pressed into contact with sheet feed rollers 24a and 24b. At this time, the movable rack plate 45 that meshes with the pressure plate shaft 25 integrated with the pressure plates 22a, 22b, the pinions 27a, 27b, and the pinion 27b is moved to the eighth position.
As shown in the figure, the mold wheel 39 is held at the forward end position (this forward end position varies depending on the stacking thickness of the sheets 10A set on the pressure plates 22a, 22b).
- The toothed gear 40 is held at the reference position shown in FIG.

In this state, the control circuit of the printer unit 1 (
When a paper feed command is given to the paper feed motor 31 from the paper feed motor 31 (not shown), and the paper feed motor 31 is started in the paper feed direction (forward rotation direction), the drive gear 34 is rotated in the direction indicated by the arrow in FIG. Accordingly, the final stage gear 29e of the paper feed gear train that meshes with the drive gear 34 rotates in the direction of arrow B in FIG. The stage gear 35d rotates in the direction of arrow C in FIG.

When gear 29e of the paper feeding gear train rotates in the direction of arrow B,
One-way bearing 30 connects paper feed roller shaft 28 and gear 2
9e, the paper feed rollers 24a and 24b rotate in the direction of arrow B in FIG.
The paper is sent out in the direction of the paper guide path 50 as shown in FIG.

Furthermore, when the gear 35d of the pressure plate retraction gear train is rotated in the direction of arrow C, the one-way bearing 37 that supports it becomes free with respect to the shaft 38, and the pawl 42 is locked in the notch 39a of the model wheel 39. Therefore, the rotation of the gear 35d is not transmitted to the mold wheel 39 and is maintained in a stopped state.

In the above-mentioned state, the unprinted paper 10A1 is sent to the printer unit 1 side as the paper feed rollers 24a and 24b rotate, and after the leading edge of the paper is detected by the paper sensor 49, the unprinted paper 10A1 is fed out for a predetermined period of time, for example, 5 lines. When the paper is fed corresponding to , the leading edge of the paper 10A1 hits between the stationary paper feed rollers 8a and Bb, and the paper 10A1 is accordingly curved as shown by the two-dot chain line in FIG. As a result, the leading edge of the paper 10A1 is brought into contact with the paper feed rollers 8a, 8b in parallel, and the paper is tilted diagonally to the paper feed rollers 8a, 8B.
Prevent it from being caught between the two, that is, from being skewed.

After the paper sensor 49 operates and the paper feed operation corresponding to five lines is completed, the paper feed motor 31 stops, the paper feed roller drive motor (not shown) of the printer unit 1 starts, and the paper Feed rollers 8a, 8b (and 9a, 9b)
Rotate. As a result, the paper feed rollers 8a and 8b grip the paper 10A that is in contact with them.
When the paper is fed by the number of lines, the paper feed rollers 8a, 8
b (and 9a, 9b) stops.

When the paper feed roller drive motor stops, the paper feed motor 3
1 is given a reverse rotation start command, and the paper feed motor 31 is started to rotate in the opposite direction to the arrow in FIG. Then, the final stage gear 29e of the paper feed side gear train that meshes with the drive gear 34 is rotated in the direction opposite to arrow B in FIG. 4, but since the one-way bearing 30 becomes free with respect to the roller shaft 28,
The roller shaft 28 including the paper feed rollers 24a and 24b does not rotate.

On the other hand, the rotation of the drive gear 34 in the direction opposite to the arrow A is gear train 3.
5a to 35d, the final stage gear 35d is rotated in the direction opposite to the arrow C in FIG. The included mold wheel 39 is rotated in the direction opposite to arrow C from the reference position shown in FIG. Here, paper feed motor 3
1 is designed to stop after the mold wheel 39 has been rotated approximately 1/2 turn.

Therefore, as the mold wheel 39b including the toothed gear 40 is rotated in the direction opposite to the arrow C from the reference position shown in FIG. When the - tooth gear 40 is engaged with the rack teeth 45a and further rotates in the direction of the arrow, the movable rack plate 45 slides in the direction of the arrow in FIG. When the movable rack plate 45 moves in the direction of the arrow, the pinion 27a meshing with the rack teeth 45b rotates in the direction of the arrow E in FIG.
As the pinion 27a rotates, it moves on the fixed rack 47 in the same direction as the moving direction of the movable rack plate 45. At this time, the rotation of the pinion 27b is transmitted to the opposite pinion 27a via the pressure plate 25, so the pinion 27a also rolls in the same direction as the pinion 27b on the fixed rack 48 meshing therewith. .

Then, when the - tooth gear 40 is rotated by a preset angle θ from the meshing start position with the rack teeth 45a as shown in FIG.
As the pressure plate shaft 25 moves from the position indicated by the two-dot chain line to the position indicated by the solid line in the figure, the pressure plate shaft 25 retreats by a certain amount. When the pressure plate shaft 25 moves backward, the pressure plates 22a and 22b integrated therewith also move back as much as possible against the pressure spring 23, and as shown in FIG.
A gap G is created between 4a, 24b and the laminated paper or the top layer of the IOA. As a result, the paper feed rollers 8a, 8
Paper 10A held in b.

The pressing force of the pressing spring 23 is released, and the paper feeding load on the paper feeding rollers 8a and 8b is reduced.

Also, the mold wheel 39 is rotated approximately 1/2 due to the reverse rotation of the paper feed motor 31.
When it has stopped after two rotations, the one-tooth gear 40 is engaged with the rack teeth 45a as shown in FIG. 13, and the pawl 42 is engaged with the notch 39b of the mold wheel 39 as shown in FIG. Since the pressure plate t-22a, 22
b is locked in the backward position, and the pressure plate 22a
, 22b are pressed against the paper feed roller 24 by the spring force of the pressure spring 23.
a.

This prevents it from being pushed back to the 24b side.

Due to the reverse rotation of the paper feed motor 31, the pressure plate 22a
, 22b, the printer unit l
starts the actual printing operation, and the printer motor (not shown)
paper feed roller 8a.

8b, 9a, and 9b are intermittently rotated to transport the paper, and the print head 7 is operated to perform printing. Then, after the paper sensor 49 detects that the end of the paper 10A fed into the printer unit 1 has passed the paper sensor 49, when printing on the paper 10A1 is completed, a paper discharge command is issued to the printer motor. In particular, the paper feed rollers 9a, 9b and the paper discharge roller 14 on the latter stage are continuously rotated to feed the printed paper 10B into the storage section 4a of the paper discharge stacker 4. When the paper has been discharged to the paper discharge stacker 4, the printer motor stops, and a reverse start command is again given to the paper feed motor 31 to start the paper feed motor 31 in the reverse direction. Then, the paper feed motor 3■ is connected to the model car 3
When the rotation corresponds to 1/4 rotation at 9, it stops again.

When the paper feed motor 31 is reversely rotated, the rotation of the drive gear 34 is transmitted to the mold wheel 3 through the reverse operation gear trains 35a to 35d.
9 and -tooth gear 40, and rotates the die wheel 39 and -tooth gear 40 about 1/4 turn in the direction of the arrow from the state shown in FIG. Then, the rank teeth 45 of the movable rack plate 45
The one-tooth gear 40 that was meshed with the gear 40 disengages from the rack teeth 45a, and the movable rack plate 45 is unlocked accordingly, so the pressure plates 22a and 22b are moved toward the paper feed rollers 24a and 24b by the pressure spring 23. While being pushed back, this pushing back action causes the pinion 27a to
, 27b on each fixed rack 47.48.
It is transferred from the state shown in the figure in the direction of the arrow F, and by the rotation of the pinion 27b in the direction of the arrow due to this transfer, the movable rack plate 45 is returned from the state shown by the solid line in FIG. 14 to the state shown by the two-dot chain line. The laminated paper 10A on 22a and 22b is pressed against paper feed rollers 24a and 24b.

Furthermore, when the mold wheel 39 is rotated approximately 1/4 turn in the direction of the arrow in FIG.
Since it is located more to the left, the mold wheel 39 including the gear gear 40 is rotated in the direction of the arrow in FIG. 14 by the spring force of the tension spring 41 and automatically returned to the original position shown in FIG. Waits for the next paper feed.

Hereinafter, the series of operations described above is performed every time a sheet of paper is fed by the paper feeding unit.

FIG. 15 is a flowchart showing a series of operating procedures for paper feeding and printing described above.

In FIG. 15, step S1 is a paper feeding process by the automatic paper feeding unit 2 to the printer unit 1, and step S2 is a step in which the paper sensor 49 determines whether the paper 10A has been fed into the printer unit 1. If "NO" here, the process advances to step S3 and error handling is performed.

In the case of rYESJ, the process proceeds to step S4, where the automatic paper feed unit 2 is further operated to feed paper to feed the paper by a predetermined amount (5 lines), causing the paper to be fed to bend as shown in FIG. let The next step S5 is a process of stopping the automatic paper feeding unit 2. Further, step S6 is a processing step in which the printer motor of the printer unit 1 operates to rotate the paper feed roller to feed the paper by a predetermined amount, for example, two lines. This is a processing step for stopping the paper feeding of the printer unit l after the paper feeding has been performed. When the process of step S7 is completed, the process proceeds to step S8, where the automatic sheet feeding unit 2 is reversely operated and the pressure plates 22a and 22b are reversely operated. Then, in the next step S9, the printer unit 1 is operated to feed the paper, and the printing process is executed in the next step SIO. The next step Sll is a step of determining whether the paper 10A fed into the printer unit 1 has passed the paper sensor 49. If rNo, the process returns to step S10. Also,
When it is determined that the paper 10A has passed, the process proceeds to step S12, where the printer motor of the printer unit 1 is operated to discharge the printed paper 10B. When the ejection of the paper 10B is completed, the printer unit 1 is stopped in step S13. In the next step S14, the automatic paper feeding unit 2 is reversely operated again to return the pressure plates 22a and 22b, which are locked in the retreated position, to a state in which paper can be fed. Then, in the next step S15, the reverse rotation of the automatic paper feeding unit 2 is stopped.

FIG. 16 is a time chart showing the operating states of the paper feed motor of the paper feed unit, the paper feed motor of the printer unit, and the paper sensor corresponding to the operating procedure shown in the flowchart of FIG. 15.

In this embodiment as described above, the forward rotation of the paper feed motor 31 rotates the paper feed rollers 24a and 24b in the paper feeding direction, and the pressure plate 22a is rotated.

The paper 10A on the paper 22b is fed into the printer unit 1, and when the feeding end of the paper 10A is caught by the paper feed rollers 8a, 8b of the printer unit by a predetermined amount, the paper feed motor 31 is reversely rotated by a predetermined amount. The movable rack plate 45 is slid by the one-tooth gear 40, and at the same time the pinion 27b and pinion 27a that mesh with the movable rack temporary 45 are moved to the fixed rack 4.
7. Pressure plate 2 by rolling along 48
2a.

22b is moved backward against the pressure spring 23, and this retreated position is held by the claw mold 39 and the claw 42 that is engaged therewith to separate the laminated paper from the paper feed rollers 24a and 24b. The binding force on the paper on the paper unit side is removed, and the paper feeding load on the paper feed roller on the printer side is accordingly reduced, and the contact state of the paper feed rollers 8a and 8b and 9a and 9b is reduced to the level of linear contact. In addition to being able to feed the paper stably and reliably even with contact pressure, by reducing the contact pressure between the paper feed rollers, the shaft that supports the paper feed rollers and its support mechanism can be constructed with low-strength materials, and the roller Since the capacity of the drive motor can also be reduced, a lightweight and inexpensive printer can be obtained.

In addition, the paper feeding operation and pressure plate retraction operation are 1
Since this is done using two paper feeding motors, the weight of the automatic paper feeding unit can be reduced.

In the above embodiment, the rank teeth 45a and 45b that mesh closely with the pinions 27a and 27b fixed to the pressure plate shaft 25 are advanced, but as shown in FIGS. 17 to 19, for example, the pressure plate The movable rack 45 may be directly attached to the shaft 25 or may be configured integrally.

In this example, the movable rack 45 has rack teeth 45a at the top that mesh with the one-tooth gear 40, and rack teeth 45a at the bottom.
It has a surface 45d that slides on the ridges of the teeth. Since the movable rack 45 is rotatably supported on the pressure plate shaft 25, the pressure plate shaft 22a
, 22b can be moved back and forth. Moreover, the left pinion 27b is shown in the drawing. When the pressure plate 22b is moved backward with the left sliding lever, the right pinion 27a also rotates in synchronization with the rotation of the left pinion 27b, making it possible to obtain the same amount of movement on both sides.

Further, in the above embodiment, the paper feeding operation of the paper feeding rollers 24a, 24b and the pressure plate 22a.

Although a case has been described in which a gear train is used as the rotation transmission mechanism for the backward operation of 22b, the structure is not limited to this, and a structure using a toothed belt, gears, etc. may be used.

Furthermore, the mechanism for locking the pressure plates 22a, 22b in the retreated position is not limited to the claw type and the claw blade type that are stopped by the claw type as in the embodiment.

[Effects of the Invention] As described above, according to the present invention, the reverse rotation of the paper feed motor is transmitted to the rank mechanism via the rotation transmission mechanism, thereby causing the pressure plate 1- to move backward against the pressing means. Furthermore, this retracted position is held by a holding mechanism to separate the stacked paper on the pressure plate from the paper feed roller, so there is no binding force on the paper on the paper feed unit side, and accordingly, the printer side The paper feeding load on the paper feeding rollers can be reduced, the paper feeding can be carried out stably and reliably even when the contact pressure between the paper feeding rollers is small, and the weight and cost of the printer can be reduced.

In addition, the paper feeding operation and pressure plate retraction operation are 1
Since it can be realized with one paper feed motor, it has the effect of making it possible to reduce the weight of the paper feed unit.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an example of an automatic paper feeder according to the present invention. FIG. 2 is a partially cutaway side view of a printer unit incorporating an automatic paper feeder according to the present invention. FIG. 3 is a side view of the paper feed motor and drive mechanism in the paper feed unit in this embodiment. FIG. 4 is a sectional view taken along line IV--IV in FIG. 3. FIG. 5 is a sectional view taken along the line -V in FIG. 3. FIG. 6 is a sectional view showing details of the paper feed roller shaft and one-way bearing portion in this embodiment. FIG. 7 is a sectional view showing details of the pressure plate retraction gear portion in this embodiment. FIG. 8 is a side view of the pressure plate retraction mechanism in this embodiment. FIG. 9 is a sectional view taken along line IX-IX in FIG. 8. FIG. 10 is an enlarged vertical sectional side view showing the paper feed stacker portion in this embodiment. FIG. 11 is a sectional view for explaining the operation of the paper feed stunning force in this embodiment. 12 to 14 are explanatory views of the operation of the pressure plate retraction mechanism in this embodiment. FIG. 15 is a flowchart schematically showing the operational procedures of paper feeding, retracting, and printing in this embodiment. FIG. 16 is a time chart showing the operation timings of the paper feed motor, paper feed roller drive motor, and girder sensor corresponding to FIG. 15. FIG. 17 is a side view showing another example of the rack mechanism according to the present invention. FIG. 18 is a side view of FIG. 17. FIG. 19 is a sectional view of FIG. 17. [Description of symbols of main parts] 1...Printer unit 2...Automatic paper feed unit 17...Frame body 18...Paper feed slider 22a 22b...Pressure play 1-24a,
24b...Paper feed roller 25...Pressure plate shafts 27a, 27b...Pinion 28...Paper feed roller shafts 29a to 29e...Gear 30.37...One-way hair ring 31... -Feeding Paper motors 35a to 35d...Gear 39...Claw type 40...-tooth gear 41...Tension spring 42...Claw 45...Movable rack plate, fixed rack, paper sensor. Figure Figure Figure Figure 8 Figure Figure Figure Figure Figure Figure Figure At ℃ Figure Figure Figure Figure Figure

Claims (1)

[Claims] (1) a pressure plate that is swingably supported by the stacker frame body in the front and back direction and presses the stacked paper; a paper feed roller that is located in front of the pressure plate and rotatably supported by the frame body; a pressing means for pressing the stacked paper against the paper feed roller via a pressure plate; a paper feed motor that is attached to the frame body and capable of forward and reverse rotation; a rotation transmission mechanism that transmits data to the
a rack mechanism that moves the pressure plate forward and backward; a rotation transmission mechanism that transmits reverse rotation of the paper feed motor to the rack mechanism to move the pressure plate backward against the pressing means; and a rotation transmission mechanism that moves the pressure plate backward against the pressing means. An automatic paper feeder comprising: a holding mechanism for holding the paper in position.