JPH0299366A - Paper feeder - Google Patents

Abstract

PURPOSE:To feed paper with an increased feed force by a separation roller and a separation pad by a construction wherein a depressing means has kept depressing at least until recording paper reaches a contact position of a feed roller and a pinch roller. CONSTITUTION:Only one sheet of recording paper separated from others by a separation roller 65 and a separation pad 66 is fed to between a feed roller 7 and a pinch roller 81. At this time, since a cam 661 never presses down a cam receiving part 661 of a pressure plate 61 until the recording paper is fed to between the roller 7 and the roller 81, the pressure plate 61 is depressed against the separation roller 65 by a spring 62. Namely, a feed force for feeding the recording paper to between the feed roller 7 and the pinch roller 81 is ensured because the recording paper on the pressure plate 61 is depressed against the separation roller 65. As a result, a sufficient feed force for feeding recording paper can be obtained even if a frictional force on the separation pad 66 is reduced for decreasing a back tension.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a paper feeding device that feeds paper to a recording device or the like.

(Prior Art) Conventionally, many recording devices in particular have a paper feed device that separates stacked recording sheets one by one and supplies them to a paper feed mechanism. A typical example is schematically shown.

The operation will be explained using these figures.

Reference numeral 61 denotes a pressure plate on which paper or the like is loaded, and is urged by a pressure plate spring 62 toward the separation roller 65°. In the paper feeding standby state, the pressure plate 61 has its cam receiver 611 pushed down by the cam 661°, and is in a position separated from the separation roller 65°.

When paper feeding starts, the cam 661'' starts rotating, and when the edge part of the cam passes the cam receiver part 611, the pressure plate 61''
The stacked recording paper is pushed up toward the separation roller by the spring 62 and is moved by the pressure plate 61 to the separation roller 65°.
is pressed against. At this time, the recording paper is fed between the separation roller 65'' and the separation pad 66 by the friction of the separation roller 65'', and is squeezed by the separating pad 66 to separate only one sheet, and then pinched with the conveyance roller 7 downstream. The separation pad 66 is sent between the roller 81 and the separation pad 66.
is biased by the pad spring 67 toward the minute m10-ra65°.

The separated recording paper is fed between the conveyance roller 7 and the pinch roller 81, and then conveyed by the frictional force of these two rollers. Here, the pinch roller 81 is urged toward the conveyance roller 7 by a spring (not shown).

The separation roller 65° has a substantially semicircular arc shape, and the presser rollers 652° provided on both sides of the separation roller 65° have a circular shape. Furthermore, since the radius of the separation roller 65° is slightly larger than the radius of the presser roller 652'', the separation pad 66 is pressed against it in the arc range of the separation roller 65°, and is pressed against the presser roller 652'' in the other range. has been done.

After paper feeding starts, the roller 65 rotates once per minute and stops at a predetermined position. That is, the recording paper is generally fed once by the circular arc portion of the separation roller 65 ゛ to ensure that it reaches between the conveyance roller 7 and the pinch roller 81 , and then the cutout portion of the separation roller 65 ゛ is opposed to the separation pad 66 . However, the separation roller 65' does not come into contact with the recording paper. At this time, the presser roller 652° is in pressure contact with the separation pad 66, and while the recording paper is being conveyed by the conveyance roller 7, the recording paper is constantly squeezed between the presser roller 652° and the separation pad 66, resulting in two sheets. This prevents the conveyance of recording paper after the first one, that is, double feeding.

By the way, in the above-described paper feeding device, during the conveyance of the recording paper after paper feeding is completed, that is, during recording in the recording device, there is a force (hereinafter referred to as pack) that pulls the recording paper in the opposite direction to the conveyance direction. (referred to as tension), which had a particularly negative effect on recording devices.

This pack tension consists of a separation pad 66 and a pressing roller 6.
This is caused by the f↑grabbing force that occurs on the recording paper between 52° and 52°. For this reason, the recording accuracy of the recording device may become unstable, or the trailing edge of the recording may be shaken when the recording paper passes between the separation bat and the presser roller and the back tension is released. , white streaks were observed.

Therefore, in order to reduce this pack tension as much as possible, the separation pads 66 are sorted within a range where double feeding does not occur. By doing so, the above problems will be alleviated.

(Problem to be Solved by the Invention) However, in the above conventional example, when the frictional force in the separation pad 66 is reduced, the conveyance force of the recording paper is reduced, and the paper slips, causing the conveyance roller 7 and the pinch roller 8
There may be cases where it is not possible to get the paper between the
A problem arose of paper jamming.

To explain this situation with reference to FIG. 11, FIG. 11 (8) shows the paper feeding standby state, in which recording paper is loaded on the pressure plate 61,
The cam receiver 611 of the pressure plate 61 is pushed down by the cam 661°.

In F[(B), when the cam 661' rotates and the cam edge portion passes the cam receiver portion all, the pressure plate 61 is pushed up by the spring 62, and the recording sheet is pressed against the separation roller 65° and sent out. ° and the separation pad 66 separates only one sheet.

After that, in the same figure (C), the cam 661° again pushes down the cam receiver part 611 of the pressure plate 61, and the recording paper on the pressure plate 61 is separated from the separation roller 65°. The paper is transported only by the transport force of the separation pad 66 that is pressed against it.

However, since the frictional force acting on the separation pad 66 is reduced in order to reduce the back tension, the force for conveying the recording paper is small, causing slippage with the recording paper. As a result, the recording paper is transferred between the conveyance roller 7 and the pinch roller 8.
1, the cutout portion of the separation roller 65' comes to a position facing the separation pad 66, and the separation roller 65'
There was a problem in that the recording paper could no longer be transported due to the angle of rotation, and the recording paper could no longer be transported, resulting in a paper jam.

In addition, in order to prevent double feeding, the frictional force acting on the separation pad needs to be of a certain level, but if the frictional force is reduced to reduce the back tension,
There were also problems in that the separation performance of the recording paper deteriorated and double feeding was likely to occur.

The present invention was made in view of the above-mentioned two problems in the prior art, and its purpose is to reduce the reduction in conveying force that occurs when the frictional force acting on the separation pad is reduced in order to reduce back tension. It is an object of the present invention to provide a paper feeding device that is compatible with the above and enables reliable paper feeding and conveyance.

[Means to solve the problem]

To this end, the present invention provides a separation pad that has a pressure contact means that can press the stacked recording paper against the separation roller, and presses the stacked recording paper against the separation roller and the separation roller by the pressure contact of the pressure contact means and the rotation of the separation roller. In a paper feeding device that feeds the stacked recording sheets one by one by feeding the stacked recording sheets one by one to a position where a conveyance roller and a pinch roller that presses against the conveyance roller contact each other, the pressing means includes at least one sheet of recording paper. It is characterized in that the pressure contact is not released until the first general feed roller and the pinch roller come into contact with each other.

[For I]

According to the above configuration, the stacked recording paper is pressed against the separation roller until the recording paper reaches the conveyance roller. This makes it possible to feed paper with increased conveyance force by the separation rollers and the separation butt.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

FIG. 1 is an external perspective view of an inkjet recording apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of the main parts of the apparatus shown in FIG. Further, FIG. 3 is a partially enlarged view of the paper feeding mechanism section in FIG. 1.

In these figures, reference numeral 61 denotes a pressure plate, on which recording sheets are loaded to be supplied to the inkjet recording apparatus. Reference numeral 62 denotes a pressure plate spring attached to the back surface of the pressure plate 61, and the pressure plate 61 is biased upward by the pressure plate spring 62. 63
is a paper width regulating plate, which is arranged so as to be able to slide on the pressure plate 61, and regulates its position according to the width of the recording paper stacked and placed on the pressure plate 61. 65 is a separation roller that separates the recording sheets stacked on the pressure plate 61 one by one.Separation roller! Ti+j
It is fixed at 651. Reference numeral 652 denotes circular press rollers, one on each side of the separation roller 65, and mounted so that they can rotate freely about the separation roller shaft 651. A pressure plate push-down cam 661 is fixed to one end of the separation roller shaft 1i51.
A separation roller gear 662 is rotatably fitted adjacent to the roller gear 1 . A spring clutch 663 is disposed between the pressure plate push-down cam 6[il and the separation roller gear 662, and the spring clutch 663 is connected to the lock ring 6 provided around the spring clutch 663.
64 is locked by the locking pawl 665, the rotational force is not transmitted (off), and when the locking pawl 665 is removed from the lock ring 664 and the locking ring 664 becomes free, the rotational force is transmitted (on). Here, the lock pawl 665 is in a position where it is released from engagement with the lock ring 664 described above due to dynamic contact with a protrusion of the carriage 5, which will be described later.

A cam receiver portion 611 is formed on the pressure plate 61 at a position that engages with a pressure plate push-down cam 661 . As a result, when the pressure plate 61 is pressed down by the pressure plate push-down cam 661, the recording paper is separated by the separation roller 65 and the presser roller 6.
52, and the push-down cam 661 is separated from the cam receiver part 61.
1, the pressure plate 61 is pushed down by the pressure plate spring 62, and the recording paper is pressed against the separation roller 65.

Further, a separation pad 66 for frictionally separating recording sheets one by one is provided on the downstream side of the pressure plate 61 in the paper feeding direction, and the classification f pad 66 is attached by a pad spring 67 toward the separation roller 65 and the presser roller 652. Forced.

The presser roller 652 has a circular shape in a cross section perpendicular to the roller iM 65 t , and the separation roller 65 has an approximately semicircular arc shape in the same cross section, and the radius of the separation roller 65 is equal to the radius of the presser roller 652 . Make it slightly larger than the radius. As a result, the separation bat 66 is pressed against the separation roller 65 in the arc range thereof, and is pressed against the presser roller 652 in the other range.

Here, the diameter of the separation roller 65 is about 20 to 30 mm, which is relatively small. As a result, as shown in FIG. 2, the angle α from the contact point of the pressure plate 61 with the separation roller 65 to the contact point of the separation pad 66 with the separation roller 65 increases, and therefore the leading edge of the recording paper picked up by the separation roller 65 The angle of entry into the separation pad 66 is the pressure plate 6
It can be set large relative to I, and even if the separation pad pressure by the pad spring 67 is small, the separation performance will not be impaired. A normal separation roller diameter (approximately 40+nm) requires a separation pad pressure of approximately 3008 nm, whereas a small diameter (approximately 20 nm) separation pad pressure is required.
~30 mm), it becomes possible to separate without any problem even when the weight is around 50 g.

Therefore, when the paper feed roller 7 is feeding the recording paper, the back tension received from the presser roller 652 and the separation pad 66 is reduced, allowing stable paper feeding.

Further, changes in the feed amount that occur when the trailing edge of the recording paper comes off from the presser roller 652 and the separation pad 66 can also be suppressed.

Reference numeral 7 denotes a paper feed roller provided on a conveyance path for further conveying the recording paper fed by the above-mentioned paper feeding mechanism to a recording position facing the recording head, and 7 is a paper feed roller provided on a conveyance path that conveys the recording paper fed by the above-mentioned paper feed mechanism to a recording position facing the recording head. Pinch rollers 81 are arranged to pinch. The pinch roller 81 is rotatably supported at both ends on the pinch roller stay 8, which is biased by a pinch roller spring 82.

Further, the pinch roller stay 8 is attached so as to be rotatable around a stay fulcrum 83. A paper guide 9 guides the recording paper fed from the paper feed mechanism to a position where it is sandwiched between the paper feed roller 7 and the pinch roller 81. IO is a paper pressing plate that presses the recording paper from floating up from the pinch roller 81.

The paper feed roller 7 is driven by a motor (not shown), and the transmission of this sharpening driving force is performed in one stage using gears, etc., and the reduction ratio is such that one rotation of the motor feeds the paper by one recording line. It has become. As a result, eccentric components of the motor itself and the motor gear that cause image deterioration, such as white lines and overlaps that occur at the joints of recording lines in a recorded image due to paper feeding, are canceled. . Further, since the drive motor to the paper feed roller 7 is decelerated by one step and the driving force is transmitted using the minimum number of transmission elements, no extra error component is included.

Reference numeral 11 denotes a hot plate having a heater on its back side, which cooperates with a power supply section to be described later to promote ink fixation on the recording paper.

There is no practical problem as long as the temperature of the hot plate 11 is in the range of 40°C to 90°C. 12 is a paper discharge roller, and a paper discharge pinch roller 13 is provided opposite to this. The paper discharge pinch roller 13 has a wheel-like shape and presses the recording surface side of the recording paper at a point to prevent the recording surface from being stained by rubbing or the like when the recording surface is incompletely fixed with ink. In addition, the feed speed of the paper ejection roller 12 is set several percent faster than the feed speed of the paper feed roller rough to give tension to the recording paper and maintain the close contact of the recording paper to the hot plate jl and the flatness of the recording paper at the recording position. That's what I do.

The hot plate II is located downstream of the recording element of the recording head 51 in the recording paper conveyance path, and prevents the heat from the hot plate 11 from directly applying to the recording element portion of the recording head 51. In addition, a gap is provided between the paper guide 9 and the hot plate 11, and the carriage 5
Detection by a paper width sensor formed of a reflective photosensor provided above is performed at the gap, thereby preventing false detection due to reflection from the guide or the like.

15 is a guide shaft, and the carriage 5 is! Tl1115
A pulley 171 is disposed on a tension plate 17 whose rotating fulcrum is coaxial with the motor 16 to which driving force is transmitted from the motor 16 to the carriage 5 via a belt 19. A constant tension is applied to the belt 19 by a tension spring 172.

Further, the carriage 5 is rotatably mounted around the guide shaft 15, and the pressing portion 54 of the carriage 5 presses the surface of the pinch roller stay 8 due to its own weight. The pressing portion 54 is a slider and slides on the pinch roller stay 8 as the carriage 5 moves.

The material of the pressing portion 54 is made of a resin having particularly high sliding properties, such as Teflon. Further, the carriage 5 has a protrusion 55 near the connection with the recording head 51.
is 0.3~. from the ejection surface of the recording head 51. Although it protrudes to the front by about 0.5 mm, it does not come into contact with the paper presser plate IO under normal conditions.

A recording head 51 has ejection orifices arranged in the paper feeding direction and ejection energy generating elements corresponding to each of the orifices. This ejection energy generating element forms droplets of recording liquid by generating thermal energy, for example, to form an image. The position of the recording head 51 relative to the carriage 5 is determined by fitting the convex portion of the recording head 51 into the hole of the carriage 5 . Further, a fixed lever 52 is mounted on the carriage 5 so as to be rotatable about a fulcrum 525.

This fixing lever 52 has an elastic part that generates a pressing force when fixing the recording head 51 to the carriage 5, and engages the fixing lever hook part of the lever 52 and the hook part of the carriage 5. The fixing lever 52
The recording head 51 is fixed to the carriage 5 by locking.

Further, the carriage 5 is provided with a paper width sensor for detecting the width of paper and the presence or absence of paper when the carriage 5 moves. This paper width sensor is installed so that its detection position is near the discharge orifice of the recording head 51 located at the most downstream position in the paper feeding direction. Furthermore, a protrusion 57 is provided near the portion of the carriage 5 that engages with the top of the guide shaft 15 to release the engagement of the locking claw 665 of the paper feeding mechanism, and a protrusion 57 is provided to disengage the lock claw 665 of the paper feeding mechanism. It contacts the lock claw 665 at a predetermined position and releases the engagement. The carriage 5 also has a cap positioning pin, which is used for positioning when the carriage 5 retreats to the recovery device position during non-recording and caps the recording element surface of the recording head 51.

150 is an ejection recovery device that caps the ejection surface of the recording head 51 and sucks ink;
is arranged on one side of the movement path outside the recording area.

In the ejection recovery device 150, 156 is the recording head 51
The cap 156 is provided with a positioning lever 157 that engages with the positioning pin of the carriage 5 described above. Reference numeral 18 denotes an ink cartridge for storing ink to be supplied to the recording head 51, and includes a drain liquid collection section for storing drain ink sucked by capping.

Reference numeral 79 denotes a power supply unit, which is fixed on the bottom plate 1002 so that its heat dissipation plate is directly below the paper discharge tray.

The operation of the configuration described above will be described below.

During non-recording, the carriage 5 is attached to the cap 1 of the recovery device 150.
56 and is in a recording standby state. After receiving recorded data from the post computer or data transfer device, the carriage 5 moves to the recovery device 150 on the moving path.
Movement is started in order to release the opening claw 665 located on the opposite side. When the lock claw 665 is released, the lock ring 664 becomes free and the rotation of the separation roller gear 662 can be transmitted to the public T roller shaft 65 and the pressure plate push-down cam 661, and the separation roller 65 and the pressure plate push-down cam 661 are rotated by the motor drive. Begin to. After starting to drive the motor, the carriage 5 moves to a position that does not prevent the lock claw 665 from returning to the position where it can return due to its own elasticity (the position where it engages with the lock ring 664), and waits. When the pressure plate push-down cam 6 [il starts to rotate, the pressure plate 61 moves upward under the bias of the pressure plate spring 62 and comes into pressure contact with the separation roller 65, and as the separation roller 65 rotates, the recording paper is moved to the position of the separation pad 66. sent to. Here, only one sheet of recording paper is separated by the ladder separation roller 65 and separation pad 66 and the paper feed roller 7 and pinch roller 81.
It is fed to the position within one rotation of the separation roller 651. When the claw of the lock ring 664 reaches the position of the lock claw 665 again, the rotation of the lock ring 665 is blocked and the rotation of the division I roller 65 is stopped.

Normally, the paper feeding operation is completed in one rotation of the M10-roller 65, but if the length to the paper feed roller 7 is longer than the circumference of the separation roller 65 due to the configuration of the device, the separation roller 65
will be rotated multiple times. In that case, the carriage 5 waits at the position where the engagement of the lock claw 665 is released until the final rotation begins. During paper feeding operation, when the leading edge of the recording paper is detected by the paper edge sensor located between the paper feed roller 7 and the separation roller 65, the paper is fed by a predetermined amount from that position, and then the paper feed roller Rotation is stopped and paper feeding and recording sheet cueing are completed.

Thereafter, the carriage 5 returns to the recovery device 150 side. At this time, a paper width sensor provided on the carriage 5 detects the paper width and the presence or absence of paper. If the paper feeding operation is performed normally, the width of the recording paper, that is, the size of the recording paper is detected, and no recording is made outside the recording paper. If no recording paper is detected, it is determined that there is a paper feed failure, an error occurs, and the process stops.

To prevent such a paper feeding failure from occurring, the disengagement operation of the lock claw 665 is performed at least twice when the carriage 5 is feeding the paper.

After paper feeding is completed as described above, the carriage 5 reciprocates in the width direction of the recording paper, and along with this, the paper feed roller 7 continues recording while feeding the paper every line recorded by the recording head 51. Let's do it. At this time, the gap between the recording head 51 and the recording paper surface is determined by the pressing portion 54 of the carriage 5 sliding on the pinch roller stay 8. That is, since the pinch roller stay 8 is provided with the pinch roller 81, when the recording paper enters between the paper feed roller 7 and the pinch roller 81, the pinch roller stay 8 moves toward the carriage 5 by that amount. Therefore, even if the thickness of the recording paper changes, the pinch roller stay 8 moves accordingly, so that a constant gap is always maintained.

The recorded recording paper passes over a hot plate 11 for fixing ink and is sent between a paper discharge roller 12 and a paper discharge pinch roller 13. The trailing edge of the recording paper is the paper feed roller 7 and the pinch roller 81
After the gap is removed, the paper ejection roller 12 and the paper ejection pinch roller 1
3, and after the final line has been recorded, the paper is sent to the paper discharge tray 1010. This paper output tray 10
The recording paper fed into the paper ejection tray 1010 undergoes in-print fixing and the like by heat generated from the heat sink of the power supply section 79 located directly below the paper ejection tray 1010.

By the way, when the recording paper is a thick paper such as an envelope or a postcard, when the recording paper is removed from between the paper feed roller 7 and the pinch roller 81, the carriage protruding portion 55 causes the paper press plate 10 to protrude toward the carriage side due to the thickness of the paper. Since it slides on the top, the ejection surface of the recording head 51 does not need to directly rub the surface of the recording paper.

The above operations complete recording on one sheet of recording paper, and the same operations are repeated thereafter.

FIG. 4 is a sectional view showing details of the paper feeding mechanism described above in FIGS. 1θ and 11. FIG. The distance A from the paper feed point to the position where the recording paper abuts the separation pad shown in the figure is set to this value in order to prevent jams, etc. that occur when the recording paper abuts the separation pad due to bending of the recording paper. There are limits to this. Therefore, when the conventional separation roller has a relatively large diameter (38 mm to 40 mm) such as 65 degrees, the angle of entry of the recording paper into the separation pad 66 defined in FIG. 6 becomes relatively small (20 degrees to 30 degrees). ).

As a result, the drag force exerted by the separation pad on the recording paper becomes smaller, and in addition, as mentioned above, by reducing the frictional force acting on the separation pad to reduce the back tension, the second and subsequent sheets of recording paper are fed. The frictional force acting on the first sheet of recording paper prevails, and double feeding is extremely likely to occur.

In the wooden embodiment, attention was paid to the above points, and as a result of experiments, the diameter of the separation roller 65 was set to about 25 mm, which is smaller than the conventional one, as shown in FIG. As a result, the pad penetration angle is 3
The angle ranges from 0 degrees to 45 degrees, which is larger than before, and the drag force exerted on the recording paper by the separation pad 66 increases, improving separation performance. Transfers have become extremely difficult.

FIG. 7 is a sectional view showing the operation of the paper feeding mechanism shown in FIG.

In FIG. 8, recording sheets are loaded on the pressure plate 61, and the cam receiver 611 of the pressure plate 61 is pushed down by the cam 581.

When paper feeding starts from this paper feeding standby state, the cam 861 starts rotating as shown in FIG. 62 and is pressed against the separation roller 65. The recording paper is taken out by a separation roller 65 that rotates in synchronization with the cam 861, and is squeezed by the separation roller 65 and separation pad 66 to separate only one sheet.

The separated recording paper is fed downstream between the conveyance roller 7 and the pinch roller 81. At this time, in the wooden embodiment, the recording paper is pinched with the conveyance roller 7, as shown in FIG. 7(C). Since the cam 661 does not push down the cam receiver of the pressure plate 61 until it is sent between the separation roller 61 and the roller 81, the pressure plate 61 is moved by the spring 62 to the separation roller 6.
It is in a state where it is pressed against 5.

That is, the recording paper is transported between the conveyance roller 7 and the pinch roller 81.
The conveyance force sent between the separation roller 65 and the pressure plate 6
This is secured by pressing the recording paper on top of the paper. As a result, even if the frictional force at the separation pad 66 is reduced in order to reduce the back tension, the conveying force is sufficient to feed the recording paper.

FIG. 8 is a perspective view showing an example in which one cam in the embodiment shown in FIG. 7 is provided on each side of the separation roller shaft.

In this case, compared to the above embodiment, the pressure plate is not pushed down to one side, but both sides can be pushed down reliably, the recording paper can be easily loaded, and it is better against skewing of the recording paper. be. In this case, it is assumed that the two cams have the same shape on the left and right as the cams described in the above embodiment, and their phases are made to match.

FIG. 9 shows an embodiment in which the pressure plate is depressed by a solenoid instead of being depressed by a cam as shown in FIGS. 7 and 8.

In the figure, a solenoid 190 for pushing down the pressure plate 61 is provided below the C1 pressure plate 61. Normally, solenoid 19
0 is in the suction state and the pressure plate 61 is in a lowered state, but when feeding the paper, by releasing the solenoid 190, the pressure plate 61 is pushed up by the pressure plate spring 62, and the recording paper is pressed against the separation roller 65. become.

The solenoid +90 releases the suction bow state at the same time as the paper feed command is input, presses the recording paper against the separation roller 65, and starts paper feeding. After that, the leading edge of the recording paper is moved to the paper feed roller 7.
The paper passes between the paper and the pinch roller 81 and is fed to a recordable position, and the paper feeding operation is completed.

After this, the solenoid 190 is returned to the suction state again at an appropriate position within the range from the position where the recording paper is caught between the paper feed roller 7 and the pinch roller 81 to the position where recording is possible. Therefore, the recording paper is at least 1f away from the pressure plate 61 until it is caught by the conveyance roller 7 and the pinch roller 81! 10-
The paper is fed with sufficient conveying force due to the pressure applied to the roller 65.

In the embodiments shown in FIGS. 7, 'fJ8, and 9, the timing for pressing down the pressure plate is set after the recording paper reaches the conveyance roller and the pinch roller, and before the recording apparatus starts recording. If this is completed, there will be no backing of the recording paper by the separation roller and pressure roller during recording, and of course no back tension will be applied, so a more accurate recorded image will be obtained and the above-mentioned problems will not occur.

In addition, in the above three embodiments, not only when the frictional force in the separation pad is reduced, but also when the frictional force by the separation pad is sufficient to obtain the paper conveyance force, there is a margin in the paper single-stroke force. It is useful because it allows you to have It goes without saying that this method is particularly effective for postcards, envelopes, and the like that require a large conveyance force.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, the stacked recording paper is pressed against the separation roller until the recording paper reaches the conveyance roller. This makes it possible to feed paper with increased conveyance force by the minute mII roller and separation bat.

As a result, even if the back tension is reduced in order to alleviate the instability of the recorded image, blurring of the trailing edge of the image, white streaks, etc., that is, even if the frictional force at the separation pad is reduced,
It is possible to provide an extremely stable paper feeding device that does not cause paper jams or the like due to insufficient conveying force.

[Brief explanation of the drawing]

FIG. 1 is an external perspective view of an inkjet recording apparatus according to an embodiment of the present invention, FIG. 2 is a main sectional view of the apparatus shown in FIG. 1, and FIG. 3 is a paper feeding mechanism section shown in FIG. 1. FIG. FIG. 4 is a schematic diagram for explaining the paper separation operation in a conventional paper feeding mechanism, FIG. Figure 7 is a schematic diagram for explaining the paper feeding operation, and Figures 8 and 9 are the pressure plate pressing mechanism of the embodiment, respectively. FIG. 1O is a perspective view showing a conventional paper feeding mechanism, and FIG. 11 is a schematic diagram for explaining the operation shown in FIG. 10. 7... Conveyance roller, 61... Pressure plate, 62... Pressure plate spring, 65... Separation roller, 66... Separation pad, 67... Bud spring, 81... Pinch roller, fill. ...Cam holder is part, 652... Presser roller, 661... Cam. Figure 3 Figure 5 Figure 6 et al.

Claims (1)

[Scope of Claims] 1) A pressure contact means capable of pressing the stacked recording paper against the separation roller, and by pressure contact of the pressure contact means and rotation of the separation roller, the stacked recording paper is brought into contact with the separation roller and the separation roller. a paper feeding device that separates the stacked recording sheets one by one by feeding the paper between the separation pad that presses against the separation roller, and feeds the sheets to a position where the conveyance roller and a pinch roller that presses the conveyance roller contact each other; In the paper feeding device, the pressure contact means does not release the pressure contact at least until the recording paper reaches a position where the transport roller and the pinch roller are in contact with each other. 2) The paper feeding device according to claim 1, wherein the paper is fed to means for forming an image on the recording paper using droplets formed by thermal energy.