JP2837974B2 - Automatic paper feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic feeding apparatus for separating stacked recording sheets (cut sheets) one by one and sending them to a processing section such as a recording section.

[0002]

2. Description of the Related Art Recording apparatuses such as printers, copiers, and facsimile machines print an image on a recording sheet (recorded) such as paper or a plastic thin plate by driving an energy generator of a recording head in accordance with recording information. It is configured to record.

The above-mentioned recording apparatuses can be classified into an ink jet type, a wire dot type, a thermal type, a laser beam type, and the like according to a recording method.

[0004] Recording sheets used in the recording apparatus include plain paper, cardboard such as postcards and envelopes, and special sheets such as plastic thin plates.

[0005] The recording sheet is supplied by hand and automatically fed by an automatic paper feeder.

The automatic paper feeder generally includes a paper feed drive section for rotating a feed roller to feed a recording sheet, and a paper feed cassette section for loading a recording sheet. By driving the paper feed drive unit using a driving force, the recording sheets are separately fed one by one.

[0007] The automatic paper feeder includes a built-in type which is incorporated in the recording apparatus and an external type which is detachably mounted.

FIG. 19 shows an automatic sheet feeding apparatus as described above.
As shown in FIG. 5, a feeding roller 41 for feeding the stacked recording sheets 13, a separating unit 42 for separating the recording sheets 13 one by one, and the feeding roller 41 by a driving force of a conveying unit of the printing apparatus. Transmission mechanism 2 for driving the motor
0 and a one-way clutch 80 provided in the middle of the driving force transmission mechanism 20 has been proposed.

In this type of automatic sheet feeder, the recording sheet 13 is pushed into the conveying roller in the recording apparatus by rotating the conveying roller and the feeding roller 41, and then the conveying roller is rotated reversely by a predetermined amount. In this case, a sequence for registering the recording sheet 13 (aligning the leading edge of the paper) is employed.
Here, when the one-way clutch 80 is rotated in the reverse direction to perform the registration, the feed roller 41 is in a free state and freely rotates with the reverse feeding of the recording sheet 13. Therefore, there is a problem that a loop cannot be formed, and the registration is inaccurate. Therefore, in the conventional automatic sheet feeding apparatus, by adopting a configuration in which a ratchet mechanism for preventing reverse rotation is provided in a portion that rotates integrally with the feed path roller 41, registration of the recording sheet at the time of sheet feeding can be performed easily and accurately. ing. This ratchet mechanism will be described with reference to FIGS.

In FIG. 19, a feed roller shaft 81 has
A ratchet portion 111 having a plurality of ratchet teeth is integrally formed on the arc-shaped outer periphery. On the other hand, on the case body side of the automatic sheet feeder 30 (in the example shown, the case body of the sheet feed drive section 40). Is pressed into contact with the ratchet teeth of the ratchet portion 111 with a predetermined elastic force, and a plate-like claw portion 112 that engages with the ratchet teeth and locks the feed roller shaft 97 is provided in a protruding manner.

FIG. 20 is a partial side view showing the ratchet mechanism, and FIG. 21 is a sectional view taken along line TT in FIG.

At the time of normal rotation of the feed roller, the ratchet teeth do not engage with the plate-like claw portions 111, so that normal paper feeding operation can be performed without any problem. On the other hand, when the one-way clutch is rotated in the reverse direction to perform registration, the ratchet portion 111 and the plate-shaped claw portion 112 that are driven to rotate in reverse in synchronization with the transport roller are engaged, and the feed roller shaft 81 is forcibly stopped. Therefore, an appropriate loop is formed at the leading end of the recording sheet due to friction between the recording sheet and the feeding roller,
The registration can be easily and accurately performed.

[0013]

However, in the conventional automatic sheet feeding apparatus as described above, during normal rotation of the transport roller 14 during the cueing operation, that is, the clutch 80
Is turned on, and while the feed roller 41 rotates forward, the plate-shaped claw 112 pressed by a predetermined elastic force slides over the plurality of ratchet teeth (the ratchet portion 111). As a result, a rattling sound is generated, such as a tick or a gee. This sound is unpleasant, and has become a problem particularly in a recording apparatus that requires quietness. In addition, particularly in the configuration using the plate-shaped claw portion as described above, when the plate-shaped claw portion slides on the ratchet portion, the plate-shaped claw portion scrapes the ratchet portion, and the ratchet teeth are worn. There was also a problem that the prevention of reverse rotation could not be realized. Furthermore, when paper is jammed in the automatic paper feeder, if the paper is pulled in the direction opposite to the paper feeding direction, the ratchet rotates in the opposite direction with a strong force, and the plate-shaped claw may be deformed. there were.

Accordingly, the present invention prevents reverse rotation of the paper feed roller without generating abnormal noise and damage to the reverse rotation preventing member when the one-way clutch reversely rotates, and easily and reliably aligns the leading edge of the recording sheet. It is an object of the present invention to provide such an automatic feeding device.

[0015]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has a feed roller for feeding a recording sheet loaded in a storage section of a recording apparatus, and a conveyance roller for the recording apparatus. An automatic paper feeder having a driving force transmitting mechanism for driving the feed roller by the driving force of the means, and a one-way clutch provided in the middle of the driving force transmitting mechanism, wherein the feeding roller is integrally rotated. An arc-shaped member,
It is characterized in that it has a fixing member provided so as to form a wedge-shaped portion between the arc-shaped member and a reverse rotation preventing member provided with play on the wedge-shaped portion.

A feeding roller for feeding a recording sheet loaded in a storage section of the recording apparatus; a driving force transmitting mechanism for driving the feeding roller by a driving force of a conveying means of the recording apparatus; And a one-way clutch provided in the middle of the driving force transmission mechanism.
An elastic member receiving portion that rotates integrally with the feeding roller is provided with an elastic member for preventing reverse rotation.

A feed roller for feeding a recording sheet loaded in a storage section of the recording apparatus; a driving force transmitting mechanism for driving the feed roller by driving force of a conveying means of the recording apparatus; And a one-way clutch provided in the middle of the driving force transmission mechanism.
A rotating body integrally rotating with the feed roller, a reversing prevention elastic member provided on the rotating body, and a biasing / abutting member against the reversing preventing elastic body, wherein the reverse rotation is performed when the feeding roller rotates in the reverse direction. A control lever for preventing rotation of the elastic member for prevention.

[0018]

According to the above construction, when the paper feed roller is rotating forward, the reverse rotation preventing member can receive a force in a direction away from the wedge-shaped portion. The member and the fixed member slide smoothly, no abnormal noise is generated, and a normal paper feeding operation is performed. On the other hand, when performing the registration taking by reversing the one-way clutch, the reverse rotation preventing member acts as a lock member on a wedge-shaped portion formed by the arc-shaped member and the fixed member when the feed roller is reversely rotated, Since the feed roller is formed into a form in which a so-called wedge is driven and the reverse rotation of the feed roller is prevented, it is possible to easily and accurately register the recording sheet at the time of sheet feeding.

Further, when the control lever is urged and abutted against the reverse rotation preventing elastic member, and the paper feed roller is rotating forward, the lever smoothly moves on the reverse rotation preventing elastic member. To slide. As a result, no abnormal noise occurs, and the normal paper feeding operation is performed. On the other hand, when the registration is performed by reversing the one-way clutch, a part of the control lever bites into the reversing prevention elastic member when the feeding roller is reversing, so that the reversing of the feeding roller is prevented. With this configuration, registration of the recording sheet at the time of paper feeding can be performed easily and accurately.

[0020]

Embodiments of the present invention will be described below with reference to the drawings. The same reference numerals in each drawing indicate the same (or corresponding) portions.

FIG. 6 is suitable for carrying out the invention,
1 is a perspective view showing a state when a recording apparatus (recording apparatus main body) 10 suitable for mounting an automatic sheet feeding apparatus according to the present invention is used.

In FIG. 6, a recording sheet insertion port 11 and a recording sheet discharge port 12 are formed on the upper surface of a recording apparatus (for example, an ink jet recording apparatus that performs recording by discharging ink by thermal energy). The recording sheet 13 inserted from the feeding roller (feed roller)
The sheet is conveyed along a substantially U-shaped recording sheet conveying path and is recorded while passing through a recording section facing the recording head 16.
After the recording, the sheet is discharged upward from the discharge port 12.

FIG. 7 is a longitudinal sectional view showing a state in which the automatic paper feeder 30 is mounted on the back of the recording apparatus 10. In this state, the sheet passes through the recording section (between the recording head 16 and the platen roller 14). A recording sheet conveyance path on a substantially straight line, that is, a conveyance path from the second recording sheet insertion port 26 to the recording sheet discharge port 12 is formed. Therefore, the automatic paper feeder 30
Is positioned so as to feed the recording sheet 13 from the sheet insertion port 26 into this linear conveyance path, and the recording apparatus 1
0 (opening surface of the entrance 26).

Reference numeral 50 denotes a paper feed cassette, which is a portion where the recording sheets 13 are loaded. The paper feed drive unit 40 is a part that feeds out the recording sheets 13 one by one and feeds them to the recording apparatus 10.

A feed roller 41 and a sliding roller 42 are mounted at a position facing the paper feed cassette section 50 of the paper feed drive section 40. A plurality of the feed rollers 41 are provided coaxially, apply a feeding force to the loaded recording sheet 13, and cooperate with separation claws 66 and 67 described later to form the recording sheet 1.
3 has a function of separating the sheets one by one and sending them into the recording apparatus 10.

The feed roller 41 is driven by using the driving force of the transport roller 15 of the recording apparatus 10. A plurality of the sliding rollers 42 are provided on an axis parallel to the axis of the feeding roller 41, and have a function of guiding the recording sheet 13 fed by the feeding roller 41 to the recording apparatus 10. The sliding roller 42 is driven in conjunction with the driving force of the conveying roller 15 of the recording apparatus 10.

Next, the sheet feeding operation of the automatic sheet feeding apparatus will be described. As shown in FIG. 8, the loaded recording sheet 1
3 is held between the pressure plate 59 and the separation claws 66 and 67, and during automatic paper feeding, the D-type (or half-moon-shaped) feeding roller 41 rotates and comes into contact with the recording sheet 13 to apply paper feeding force. Can be While the feed roller 41 makes one rotation, one of the uppermost layers is separated and passes through the sliding contact roller 42 to form the recording device 10.
The paper is fed up to the cueing position inside. The sliding contact roller 42
Is disposed near the paper path surface 31 in parallel with the feed roller 41, and is rotated at a peripheral speed slightly (for example, 8%) faster than the transport roller in conjunction with the transport roller 14 of the recording apparatus 10. Is done. On the other hand, the feed roller 41 is also driven by using the driving force of the transport roller 15, and the feed roller is controlled to be ON / OFF during normal rotation and is disconnected (OFF) during reverse rotation. Since the recording sheet 13 is driven via the spring clutch 70, the recording sheet 13 is driven in the normal rotation direction only at a predetermined timing, such as when the recording sheet 13 is caught.

In FIG. 1, the rotation of a driven gear (transfer gear) 53 driven in synchronization with the rotation of the conveying roller 15 of the recording apparatus 10 is performed by a series of gear trains 75, 76, 7
It is transmitted to the shaft 81 of the feed roller 41 via 7, 47, 79. The gear 77 in the middle is fixed to the shaft 49 of the sliding roller 42. The gear 75,
76 and 47 are idle gears.

Here, the gear 79 is mounted coaxially with the shaft 9 of the feed roller 41. The gear 79 and the feed roller shaft 81 are connected via a one-way clutch (for example, a spring clutch) 80. ing. This one-way clutch 80 is always disconnected (off) in the reverse rotation direction,
It is constituted by a spring clutch whose on / off is controlled even in the normal rotation direction.

As the one-way clutch 80, for example, one that operates as follows is used. First,
Transport roller (platen roller) 15 based on a paper feed signal
Is rotated a small amount (rotation in the direction opposite to the transport direction), the one-way clutch 80 is turned on by the reverse rotation of the gear 79 (clutch trigger). In the normal state of the ON state, the feed roller 41 is in a state in which the feed roller 41 can be normally rotated by the normal rotation of the transport roller 15. At this time, the feed roller 41 including the D-shaped (or half-moon) unequal side roller is
It is at a reference position or an initial position away from the recording sheet 13.

Next, when the transport roller 14 is rotated forward by a predetermined amount, the feed roller 41 rotates in conjunction therewith, and one recording sheet 13 is fed to a position beyond the drawing portion of the transport roller 15. You. The sensor detects that the recording sheet 13 has reached the draw-in section, and the stop position of the transport roller 15 at this time is controlled by the detection signal of the sensor.

Next, the conveying roller 15 is rotated in the reverse direction by a predetermined amount, and the leading end of the recording sheet 13 is retracted to a position where the recording sheet 13 comes out of the sheet pull-in section. By the reverse rotation of the transport roller 14 at this time, a loop is created at the leading end of the recording sheet 13 and registration is performed (operation to make the leading end of the recording sheet 13 parallel).

The one-way clutch (for example, a spring clutch) 80 is still in an ON state by the clutch trigger, and is in a state where rotation can be transmitted in the normal rotation direction.

Then, the conveying roller 15 is rotated forward by a predetermined amount, and the recording sheet 13 is conveyed to the recording start position (start position) by the normal rotation of the conveying roller 15 and the feed roller 41.

During the forward rotation, the D-type feeding roller 41
Is separated from the recording sheet 13, that is, the feeding roller 4
When 1 rotates one turn and returns to the reference position (initial position), the one-way clutch 80 is switched off, and the paper feed roller 41 stops at the reference position.

In this way, during one rotation of the feeding roller 41, only one recording sheet 13 is fed into the recording apparatus 10 and set in the cueing state.

Thereafter, recording on the recording sheet 13 is performed based on the image information.

During this recording, the one-way clutch 80 remains off, and the feed roller 41 remains stopped at the reference position despite the normal rotation (paper feed) of the transport roller 15.

FIG. 9 is a longitudinal sectional view showing the structure of the one-way clutch (spring clutch) 80, and FIGS.
3 is a diagram showing a control ring of the control ring in FIG. 9 and a control lever 87 for regulating the operation of the control ring.

A one-way clutch (spring clutch) 80 attached to the feed roller shaft 81 has a boss (winding drum) 195 integrated with the gear (clutch gear) 79,
The coiled clutch spring 177 and the clutch drum 17
8 and a control ring 179.

As shown in FIGS. 10 to 13, a control lever 131 for controlling the clutch operation is pressed against the control ring 179 radially inward and axially by a control spring 132. .

The clutch drum 178 is fixed to the feed roller shaft 81 and rotates integrally.

On the other hand, the clutch gear 79 having the boss 176 is rotatably fitted to the feed roller shaft 81.

A clutch spring receiving portion is provided on the peripheral surfaces of the boss portion 176 and the clutch drum 178, and a coil-shaped clutch spring 177 is mounted on both sides. One end of the clutch spring 177 is engaged with a hole 182 formed in the clutch drum 178, and is always connected to the clutch drum 178. The other end of the clutch spring 177 has a notch 1 formed in a control ring 179 rotatably fitted on the outer periphery of the clutch spring 177.
It is hooked on 83.

The control ring 179 has a shape as shown in FIGS. 10 to 13, and the left rotation in the plan view of FIG. 10 corresponds to the feeding direction of the feeding roller 41.

The control lever 131 is rotatably fitted to a shaft 150 provided on the case body 129.
As shown in FIGS. 13 and 11, the control spring 132 urges the control ring 179 axially (to the right in FIG. 11) and radially inward.

In the paper feed standby state (the reference non-contact position of the feed roller 41), the control lever 131 is stopped by being caught by the notch 185 of the control ring 179.

When a paper feed command is issued from the control unit, first, the conveying roller 15 is rotated in the reverse direction by a predetermined amount so that the clutch gear 79 is rotated.
Is rotated in the loosening direction of the clutch spring 177 wound around the boss portion (winding drum portion) 176,
Actually, since the load of the feed roller shaft 81 such as contact with the recording sheet 13 is small, the initial tightening torque of the clutch spring 177 acts, and the rotation of the clutch gear 79 is transmitted, and the spring of the clutch spring 177 is transmitted. The control ring 179 whose end is hooked rotates in the reverse direction by a predetermined number of steps. By the rotation of the control ring 179 in the reverse direction, the control lever 131 moves outward in the control ring radial direction along the slope 186 of the notch 185 of the control ring 179, and slides along the surfaces 187 and 188.

Next, the control ring 179 is rotated substantially one turn in the forward direction. That is, when the clutch gear 79 is rotated in the forward direction in synchronization with the forward rotation of the transport roller 15, the boss 176
The boss portion 176 and the clutch spring 1 are rotated in a direction in which the clutch spring 177 wound around
77 and the clutch drum 178 rotate integrally, torque is transmitted to the feed roller shaft 81 and the feed roller 41,
It is driven to rotate in the forward direction. At the same time, the clutch spring 17
Control ring 179 engaged with one end of 7 is also rotated in the same direction.

Due to the rotation at this time and the urging force of the control spring 132, the control lever 131 moves onto the surface 188, is pressed against the surface 187, and slides along the surface 187 and the surface 188.

By this forward rotation, the feed roller 41 is driven to start feeding the recording sheet 13.

When the forward rotation at a predetermined angle is performed, the control lever 131 first descends to the surface 189 by the slope 193, and is guided to contact the surface 189 following the surface 194.
Is caught in the notch 185 of the control ring 179,
The rotation of the control ring 179 stops.

That is, due to the normal rotation of the predetermined angle, the control lever 131 first moves the surface 18 by the slope 193.
9 and slides a predetermined angle along the surfaces 187 and 189.

When the control lever 131 is further rotated in the forward direction, the control lever 131 is lifted along the slope 194,
Glide along the surfaces 189, 190.

After further rotating in the forward direction and making a full rotation, it collides from the surfaces 189 and 190 into the notch 185 formed at a position where it collides and falls, and the notch 185
And the rotation of the control ring 179 is stopped.

When the control ring 179 is stopped, the one-way clutch 80 is turned off again (a state in which torque is not transmitted even in the forward rotation).

To summarize the above movements, the feed roller 41 is driven by the initial reverse rotation of the control ring 179 (a predetermined number of pulses).
The paper feed trigger for one rotation of the feed roller is applied. From there, the control roller 179 is rotated once in the forward direction.
1 is driven to rotate, the feed roller 41 and the control ring 179 make one rotation and return to the initial position, and the control lever 131 is fitted into the notch 185 again to be in the clutch-off state, and the feed roller 41 is turned off. Stop at the reference position.

Thus, the feeding operation of the recording sheet 13 is completed by rotating the feeding roller 41 once by using the driving force of the conveying roller 15.

Next, the reverse rotation preventing mechanism according to the present invention will be described in detail.

In FIG. 1, 1 is an arc-shaped member which rotates integrally with the feeding roller, 2 is a fixing member provided so as to form a wedge shape with the arc-shaped member, and 3 is a wedge-shaped member. It is a reverse rotation prevention member provided at the portion. The arc-shaped member 1 is fixed to or integral with the feed roller shaft 81, and rotates in synchronization with the feed roller 41.

Here, the principle of the reverse rotation preventing mechanism of the present invention is as follows.
2A described with reference to FIGS. 2A and 2B, the arc member 1 is an arc member, the fixing member 2 is a wall, and the reverse rotation preventing member is a cylindrical member. The reverse rotation preventing member (cylindrical member) 3 falls by its own weight into a wedge-shaped portion formed between the arc member 1 and the surface 2a of the wall 2. . Here, the circular member 1 and the wall 2 are made of a material such as plastic, while the reverse rotation preventing member (cylindrical member) 3 is made of a high friction material such as rubber.

When the arc member 1 rotates forward in the direction A, that is, in the normal rotation direction, the reverse rotation preventing member (cylindrical member) 3 receives a force in a direction away from the circular member 1 and the wall 2, and the arc member 1 It can rotate smoothly.

On the other hand, when the circular member 1 rotates in the direction B, that is, in the reverse rotation direction, the reverse rotation preventing member (cylindrical member) 3 is pressed against the wall 2 by the rotation of the circular arc member 1. The cylindrical member 3 is given such a rotation as to roll down the wall in the C direction by the rotation of the arc member 1 in the B direction. Then, a force that is further pressed against the wall 2 is applied to the cylindrical member 3, so that the cylindrical member 3 bites into the wedge-shaped portion between the arc member 1 and the wall 2. Here, as described above, since the cylindrical member 3 is made of a high friction material, the cylindrical member 3 does not slip between the arc member 1 and the wall 2, and finally the circular member 1 is prevented from rotating in the B direction and locked. Reach.

FIG. 2B shows a structure in which the reverse rotation preventing member is not a cylinder but a wedge member having a triangular cross section. Since this wedge member is also made of a high-friction material, it is possible to obtain exactly the same operation as the structure shown in FIG. As described above, various shapes of the reverse rotation preventing member can be considered.

FIG. 3 shows an embodiment in which the reverse rotation preventing mechanism described in FIG. 2 is actually used in an automatic sheet feeder. FIG. 4 illustrates the operation of the reverse rotation preventing mechanism in this embodiment.

In FIG. 3, the arc member 1 rotates about the feed roller shaft 97, and is fixed to or integral with the feed roller shaft. That is, the arc member 1 and the feed roller 41 rotate on the same axis in synchronization. A fixing member 2 is provided so as to sandwich the arc member 1 from both sides. A wedge shape is formed between the arc member 1 and the fixing member 2, and a cylindrical reverse rotation preventing member 3 rides there by its own weight.

FIG. 4C shows the state of the reverse rotation prevention unit at the time of starting the sheet feeding of the automatic sheet feeding apparatus of the present embodiment. At this time, the arc member 1 does not form a wedge shape with the fixed member 2, and the reverse rotation preventing member (cylindrical member) 3 is stationary at the V-shaped portion of the fixed member 2. As described above, when the paper feed trigger is activated, the feed roller starts rotating, and when the paper is fed, the arc member 1 rotates (forward rotation) in synchronization with this.
Start. Then, as shown in FIG. 4 (a), the arc member 1 raises the reverse rotation preventing member (cylindrical member).

When the arc member 1 reaches the position shown in FIG. 4B, a wedge-shaped portion is formed between the arc member 1 and the fixing member 2. At this position, the paper is conveyed to a position beyond the draw-in portion of the conveying roller 15. Immediately after this,
The conveying roller 15 is reversed by a predetermined amount, and the leading end of the recording sheet 13 is retracted to a position at which the recording sheet 13 comes out of the sheet retracting section.
An edge 131a is formed on the control lever 131, and faces the elastic member 2 at a certain angle. As described above, the control lever 131 is urged in the axial direction and the radial direction inward with respect to the control ring 179 by the control spring 132, and in the normal state, the edge portion is the elastic member 2 Does not touch the arc of The feed roller rotates, and the edge portion comes into contact with the circular arc portion of the elastic member 2 at a certain timing described later. This situation is shown in FIGS.

FIG. 4 shows a state immediately before the feed roller 41 feeds out the recording paper 13, and the control lever 131 is in contact with a control ring 179 (not shown). When the paper feed trigger is activated and the feed roller starts to rotate, the recording sheet 13 is fed out and fed to a position beyond the draw-in portion of the transport roller 15. Immediately after this, the conveying roller 15 is reversely rotated by a predetermined amount to retract the leading end of the recording sheet 13 to a position where the recording sheet 13 comes out of the sheet retraction portion. At this time, as described above, the reverse rotation preventing member 3 To prevent reversal. Since the arc member 1 and the feed roller 41 rotate in synchronization with each other, the reverse rotation of the feed roller is also prevented at this time.

In this way, when the registration of the recording sheet 13 is performed (paper leading edge alignment) by the reverse rotation of the transport roller 15, the reverse rotation of the feed roller 15 is reliably prevented, so that the registration can be accurately removed. It can be carried out.

Here, the timing for reversing the transport roller 15 varies to some extent depending on the state of the recording sheet 13 and the like, and the position and length of the arc portion of the elastic member 2 are set according to the variation. is there.

Then, the conveying roller 15 is rotated forward to perform the cueing of the recording sheet 13 by a predetermined amount. At this time, the reverse rotation preventing member 3 is connected to the arc-shaped portion of the arc-shaped member 1 at the wedge-shaped portion. , And does not hinder the forward rotation of the arc member. Therefore, abnormal noise such as ratchet noise does not occur as in the conventional anti-reverse mechanism using a ratchet, and there is no need to worry about the wear of the anti-reverse member 3, and the feeding as in the conventional example is not required. Feed roller 1
Since the member for preventing reverse rotation of 4 is not plate-shaped, it can have sufficient strength and does not break even when a large force is applied.

FIG. 5 shows a second embodiment of the present invention. In this configuration, the fixing member is formed with a long hole, and the reverse rotation preventing member (cylindrical member) 3 is freely provided therein. The operation in this configuration is exactly the same as that shown in FIG. Here, since the reverse rotation preventing member 3 is guided by the long hole provided in the fixed member 2, the movement of the reverse rotation preventing member 3 is more stabilized.

In the above embodiment, the anti-reverse member is formed of a high friction material. Conversely, the anti-reverse member 3 is formed of a material such as plastic, and the arc member 2 and the fixing member are fixed. The same effect can be obtained even if the high friction material is used for the portion of the member 2 that contacts the reverse rotation preventing member 3.

The reverse rotation preventing member 3 is configured to fall on the upper part of the wedge by its own weight, but may be urged with a light force by a spring or the like. By doing so, this mechanism can be used even in a position where its own weight cannot be used.

Next, the third embodiment of the reverse rotation preventing mechanism according to the present invention will be described.
Will be described in detail.

In FIG. 14, reference numeral 5 denotes a rotating body (hereinafter referred to as an elastic member receiving portion), and reference numeral 6 denotes an elastic member. A schematic diagram of this part is shown in FIG. In the present embodiment, the elastic member 6 is a ring-shaped rubber, and is wound around the elastic member receiving portion 5 while being slightly stretched. The elastic member receiving portion 5 is fixed to or integrated with the feed roller shaft 81, and rotates in synchronization with the feed roller 41.
When the elastic member 6 is wound around the elastic member receiving portion 5,
The elastic member 6 has an arc portion 6a having a predetermined diameter coaxial with the feed roller shaft 81.

On the other hand, an edge 131a is formed on the control lever 131 and faces the elastic member 6 at a certain angle. As described above, the control lever 131 is urged inward in the axial direction and the radial direction with respect to the control ring 179 by the control spring 132, and in the normal state, the edge portion is in contact with the elastic portion 6.
Is not in contact with the circular arc portion 6a. The feed roller 41 rotates, and the edge portion contacts the arc portion 6 a of the elastic member 6 at a certain timing described later. Figure 1 shows this situation.
7 and FIG.

FIG. 17 shows a state immediately before the feeding roller 41 sends out the recording paper 13, and the control lever 131 is in contact with a control ring 179 shown in FIG. When the paper feed trigger is activated and the feed roller starts to rotate, the recording paper 13 is sent out and fed to a position beyond the draw-in portion of the transport roller 15. Immediately after this, the transport roller 15 is reversed by a predetermined amount to retract the leading end of the recording sheet 13 to a position where it has come out of the sheet retracting portion. Is in contact with the circular arc portion of.

Here, the timing of reversing the transport roller 15 varies to some extent depending on the condition of the recording paper 13 and the like, and the position and length of the arc portion 6a of the elastic member 6 are set according to the variation. is there.

When the transport roller 15 rotates in the reverse direction, the feed roller 41 tries to rotate in the reverse direction due to the slack torque of the one-way clutch (spring clutch) 80. However, the edge 131a of the control lever 131 is in contact with and biased against the elastic member 6,
When the elastic member 6 rotates in the reverse rotation direction of the feed roller 15, the edge portion 131a bites into the elastic member 6, and the reverse rotation of the elastic member 6, that is, the reverse rotation of the feed roller 15, is prevented. This situation is explained clearly in FIG.

That is, in FIG.
The edge 1a is provided at such an angle as to be drawn in with respect to the rotation of the elastic member 6 in the direction A, so that when the elastic member 6 rotates in the direction A, the edge portion 131a bites into the elastic member 6 to prevent rotation. On the other hand, when the elastic member 6 rotates in the direction B, the edge portion can receive a force against the biasing force in the direction C of the edge portion 131a due to the rotation of the elastic member 6 in the direction B. And smoothly slides on the surface of the elastic member 6 while being in contact with the elastic member 6.

As described above, when the registration of the recording paper 13 (paper leading edge alignment) is performed by the reverse rotation of the transport roller 15,
Since the reverse rotation of the feed roller 15 is reliably prevented, the registration can be accurately performed.

When the feed roller 15 rotates forward, the edge portion 131a slides smoothly on the surface of the elastic member 6, so that ratchet noise unlike the conventional example does not occur. . In addition, in FIG. 16, the edge portion 131a with respect to the rotation of the elastic member 6 in the A direction.
Since the edge portion 131a is automatically bitten only by lightly contacting the elastic member, the urging force in the C direction of the edge portion 131a may be small, and there is no need to worry about wear of the sliding elastic member 6. Further, as in the conventional example, the feed roller 1
Since the member for preventing the reverse rotation of 5 is not a plate-shaped member, it can have sufficient strength and does not break even when a large force is applied.

Here, the elastic member 6 may be an O-ring having a circular cross section other than the flat ring-shaped member as in the present embodiment. In order to reduce the cost as much as possible, An elastic member may be provided only in the arc portion where the edge portion 131a contacts.

Further, in the present embodiment, the reverse rotation of the feed roller 41 is prevented by using the control ring.
In an automatic sheet feeding apparatus which does not have a lever member such as a control ring in advance, a similar configuration can be obtained by providing the lever member 131 having an edge portion as in this embodiment.

The recording apparatus 10 may be a serial scan type recording apparatus in which a recording head is mounted on a carriage that moves along the recording sheet 13, or a recording head that covers a recording area of the recording sheet 13 in the paper width direction. Any type of recording device can be used, such as a line-type recording device that uses.

In addition to the recording apparatus 10 using one recording head, a color recording apparatus using a plurality of recording heads, or a gradation recording using a plurality of recording heads having the same color but different densities. Recording device for
A recording device with any number of recording heads can be used.

The present invention provides an excellent effect particularly in a recording apparatus using an ink jet recording method among various recording methods and using a valve jet recording head proposed by Canon Inc. Things.

The typical configuration and principle are described in, for example, US Pat. Nos. 4,723,129 and 47,407.
It is preferable to use the basic principle disclosed in the specification of Japanese Patent No. 96.

This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, it is applicable to a sheet or a liquid path holding a liquid (ink). Generating heat energy in the electrothermal transducer by imprinting at least one drive signal corresponding to the recorded information on the electrothermal transducer, which corresponds to the recorded information and gives a rapid temperature rise above the boiling point. At the very least, film boiling occurs on the heat-acting surface of the recording head, and as a result, bubbles in the liquid (ink) corresponding one-to-one to this drive signal can be formed, which is effective.

By discharging the liquid (ink) through the discharge opening by the growth and contraction of the bubble, at least one droplet is formed.

When the driving signal is formed into a pulse shape, the growth and shrinkage of the bubbles are performed immediately and appropriately, and the ejection of the liquid (ink) having particularly excellent responsiveness can be achieved, which is more preferable.
The driving signal in the form of a pulse is disclosed in US Pat.
Those described in JP-A Nos. 3359 and 4345262 are suitable.

Further, if the conditions described in US Pat. No. 4,313,124 relating to the temperature rise rate of the heat acting surface are adopted, more excellent recording can be performed.

[0095] The structure of the recording head may be a combination of a discharge port, a liquid path, and an electrothermal converter (a linear liquid flow path or a right-angled liquid flow path) as disclosed in the above-mentioned specifications. U.S. Pat. No. 4,558,833 and U.S. Pat.
A configuration using the specification of Japanese Patent No. 59600 is also included in the present invention.

In addition, Japanese Unexamined Patent Publication No. 59-123670 discloses a configuration in which a common slit is used as a discharge portion of an electrothermal converter for a plurality of electrothermal converters. The effect of the present invention is effective even if the configuration is based on JP-A-59-138461 which discloses a configuration in which the holes correspond to the discharge portions.

Further, the present invention can be applied to a full-line type recording head having a length corresponding to the maximum width of a recording medium on which a recording apparatus can record. Such a recording head may have a configuration that satisfies the length by combining a plurality of recording heads, or a configuration as a single integrally formed recording head.

In addition, a replaceable chip type which can be electrically connected to the apparatus main body or supplied with ink from the apparatus main body by being attached to the apparatus main body even in the serial type as described above. The present invention is also effective when a recording head of the type described above or a cartridge type recording head provided integrally with the recording head itself is used.

The type and number of recording heads to be mounted are, for example, not only those provided for one color ink but also a plurality of inks having different recording colors and densities. A plurality may be provided.

In addition, the form of the ink jet recording apparatus of the present invention is not only used as an image output terminal of an information processing apparatus such as a computer, but also a copying apparatus combined with a reader or the like, and further, a facsimile having a transmission / reception function. It may take the form of a device,

[0101]

As is apparent from the above description, according to the present invention, the feeding roller for feeding the loaded recording sheet and the driving roller for driving the feeding roller by the driving force of the conveying means of the recording apparatus are used. And a one-way clutch provided in the middle of the driving force transmission mechanism, wherein an arc-shaped member that rotates integrally with the feed roller and the arc-shaped member A fixing member provided so as to form a wedge shape, and a reverse rotation prevention member loosely provided in the wedge-shaped portion, wherein the reverse rotation prevention member;
Alternatively, the arc-shaped member and the fixing member are formed of, for example, a high friction material such as rubber, and the reverse rotation preventing member is locked to a wedge-shaped portion formed by the arc member and the fixing member when the feeding roller is rotated in the reverse direction. By acting as a member, a so-called wedge is formed, and the feed roller is configured to prevent reverse rotation, so that abnormal noise such as ratchet noise does not occur, and the reverse rotation preventing member is worn out. It is possible to provide an automatic sheet feeding apparatus capable of easily and accurately registering a recording sheet at the time of sheet feeding while preventing the sheet from being damaged or damaged.

Further, according to the present invention, a control lever which is provided with an elastic member (for example, rubber) for preventing reverse rotation at a portion which rotates integrally with the feed roller, and which is urged against and abutted against the elastic member for preventing reverse rotation. When the feed roller reversely rotates, a part of the control lever bites into the reverse rotation preventing elastic member to prevent reverse rotation of the feed roller, thereby generating an abnormal noise such as ratchet noise. Without
Further, it is possible to provide an automatic sheet feeding device capable of easily and accurately registering a recording sheet at the time of sheet feeding while preventing the reverse rotation preventing member from being worn or damaged.

[Brief description of the drawings]

FIG. 1 is a perspective view of an automatic sheet feeder according to a first embodiment of the present invention.

FIG. 2 is a perspective view schematically showing the principle of a reverse rotation prevention mechanism in FIG.

FIG. 3 is a schematic cross-sectional view showing a reverse rotation prevention mechanism.

FIG. 4 is a schematic cross-sectional view illustrating how to prevent reverse rotation in a paper feeding state.

FIG. 5 is a schematic cross-sectional side view illustrating how to prevent reverse rotation in a paper feeding state according to a second embodiment of the present invention.

FIG. 6 is a schematic perspective view showing a use state of a recording apparatus to which the automatic sheet feeder of the present invention is attached.

FIG. 7 is a schematic vertical sectional side view showing a state where the recording apparatus is mounted on the moving sheet feeding apparatus of the present invention.

FIG. 8 is a vertical sectional side view of a single unit of the automatic sheet feeder of the present invention.

FIG. 9 is a longitudinal sectional side view showing the structure of a one-way clutch.

FIG. 10 is a front view showing a control ring and a control lever in FIG. 9;

FIG. 11 is a sectional view taken along line QQ in FIG. 10;

FIG. 12 is a sectional view taken along line RR in FIG. 10;

FIG. 13 is a sectional view taken along line SS in FIG. 10;

FIG. 14 is a perspective view showing an automatic sheet feeder according to a third embodiment of the present invention.

FIG. 15 is a perspective view schematically showing a reverse rotation prevention mechanism in FIG. 14;

FIG. 16 is a schematic vertical sectional side view showing the concept of the reverse rotation prevention mechanism of FIG. 15;

FIG. 17 is a schematic vertical cross-sectional side view for explaining how to prevent reverse rotation in a paper feeding state according to the third embodiment.

FIG. 18 is a schematic cross-sectional view illustrating how to prevent reverse rotation in the sheet feeding state.

FIG. 19 is a perspective view showing a reverse rotation preventing mechanism applied to a conventional automatic device.

FIG. 20 is a partial side view showing a ratchet mechanism provided on a feed roller shaft of a conventional automatic sheet feeder.

FIG. 21 is a view taken along line TT in FIG. 20;

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 arc-shaped member 2 fixing member 3 reverse rotation preventing member 4 wedge-shaped portion 5 rotating body (elastic member receiving portion) 6 elastic member for preventing reverse rotation 10 recording device (main body) 11 recording sheet insertion port 12 recording sheet discharge port 13 recording sheet Reference Signs List 15 transport roller 20 drive transmission mechanism 30 automatic paper feeder 40 paper feed drive unit 41 feed roller 50 paper feed cassette 80 one-way clutch

Claims (7)

(57) [Claims] A feed roller for feeding a recording sheet loaded in a storage section of the recording apparatus; a driving force transmission mechanism for driving the feed roller by a driving force of a conveying unit of the recording apparatus; In an automatic paper feeder having a one-way clutch provided in the middle of the driving force transmission mechanism, an arc-shaped member that rotates integrally with the feeding roller, and a wedge-shaped portion is formed between the arc-shaped member and the arc-shaped member. An automatic sheet feeding device, comprising: a fixing member provided as described above; and a reverse rotation preventing member provided to play in the wedge-shaped portion. 2. The automatic sheet feeding device according to claim 1, wherein the reverse rotation preventing portion is made of a high friction member such as rubber. 3. The automatic sheet feeding apparatus according to claim 1, wherein the arc-shaped member and the fixing member are made of a high friction member such as rubber. 4. A feeding roller for feeding a recording sheet loaded in a storage section of a recording device, a driving force transmission mechanism for driving the feeding roller by a driving force of a conveying unit of the recording device, An automatic sheet feeding device having a one-way clutch provided in the middle of the driving force transmission mechanism, an elastic member receiving portion that rotates integrally with the feed roller, and a reverse rotation preventing elastic member provided on the rotating body; An automatic sheet feeding device, comprising: a control lever that is urged and abutted against the reverse rotation preventing elastic body, and that prevents rotation of the reverse rotation preventing elastic member when the feed roller reversely rotates. 5. A lever member which is urged and abutted against the reverse rotation preventing elastic member, and a part of the lever portion bites into the reverse rotation preventing elastic member when the feed roller reversely rotates. 5. The automatic sheet feeding device according to claim 4, wherein reverse rotation of the feed roller is prevented. 6. An automatic sheet feeding apparatus according to claim 4, wherein said lever member latches a control ring for controlling rotation of said feed roller to turn on / off said one-way clutch. 7. The ink jet recording apparatus according to claim 1, wherein the recording apparatus to which the automatic sheet feeding apparatus is mounted is an ink jet recording apparatus that performs recording by discharging ink by thermal energy.
7. The automatic paper feeder according to any one of claims 6 to 6.