JPH0524685A - Sheet member transport device and image forming device - Google Patents

Abstract

PURPOSE:To prevent the aslant traveling by installing a drive control means which does not apply a brake load when a force in the direction for feeding a sheet member is applied, while applies the brake load, permitting the reverse revolution in a certain degree, when a force in the reverse direction is applied, between a sheet member feeding driving means and a sheet member transport means. CONSTITUTION:A paper feeding gear 10a. clutch 10b, clutch gear 10c etc., which constitute a drive transmission means 10 are arranged on one edge side of the shaft 9b of a transport roller 9. A shaft clamping spring 9c as a drive control means (torque limitter) which is externally fitted at one edge of the shaft 9b of the transport roller 9 permits the revolution of the transport roller 9 in the paper feeding direction (e) substantially free from the load, when the force in the direction (e) acts onto the transport roller 9, and on the contrary if the force in the reversely paper feeding direction acts on the transport roller 9, the inside diameter of the spring 9c reduces, and the action for clamping the shaft 9b is generated, and acts to regulate the revolution in the reversely paper feeding direction of the transport roller 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a recording device (printer) as an information output device in a word processor, a personal computer or the like, an image forming device such as a copying machine or a facsimile, and other various sheet material-using devices. , Sheet material storage (sheet material stacking table, tray, deck, removable paper cassette, manual paper feeding table, etc.)
Sheet material (printing paper, transfer paper, photosensitive paper, electrostatic recording paper, printing paper, O
The present invention relates to a sheet material feeding device (paper feeding device) for feeding HP sheets, envelopes, postcards, sheet originals, etc.) to a sheet material processing unit such as an image forming unit, an exposure unit, and a processing unit, and an image forming apparatus.

[0002]

2. Description of the Related Art For the sake of convenience, a sheet material feeding device of a printer shown in FIG. 4 as an example will be described.

Reference numeral 6 is a sheet material accommodating portion (sheet material stacking means).
Is a sheet material mounting table (sheet material guide means), and is disposed as a front and downward inclined surface table. Reference numeral 8 denotes a pressing plate (middle bottom plate) arranged on the upper surface side of the table, which is constantly urged to float from the inner surface of the table by a spring member 8a. Reference numeral 7 is a sheet material separating claw (sheet material separating means) provided at both corners on the tip side of the table. Reference numeral 5 is a sheet material (printing paper, recording medium) stacked and accommodated on the table 6, and the leading end side is aligned with the separation claw 7 and locked and placed.

A feeding roller 9 serves as a sheet material feeding means for feeding the sheet material on the table 6. 9b is a shaft portion of the feeding roller, and 9a is a roller portion integrated with the shaft portion. The uppermost sheet material surface of the stacked set sheet material 5 on the table 6 with respect to the roller portion 9a of the paper feeding roller 9 is the spring member 8
The stacking sheet material is lifted by the pressing plate 8 that is lifted up and urged by a to make a pressing contact.

Reference numeral 16 denotes a conveying roller which is arranged on the front side of the table 6 in the sheet material feeding direction and serves as a sheet material intermediate transfer means. Reference numeral 16b is a shaft portion of the conveying roller, and 16a is a roller portion integrated with the shaft portion.

Reference numeral 26 denotes a sheet material guide plate which guides the fed sheet material 5 from the side of the table 6 to the lower surface side of the transport roller 16, and the sheet material guide plate which is inclined forward and downward, and the leading end side thereof is the roller portion 16a of the transport roller 16. An arc curve is formed along substantially the lower half surface, and the roller 16 is extended to the left side surface side.

Reference numerals 17A and 17B are the first and the first, which are arranged by pressing the conveying roller 16 with spring members or the like at two places on the lower surface of the conveying roller 16 on the upstream side and the downstream side in the sheet material conveying direction. Two pinch rollers. These pinch rollers are respectively fed from the through holes 26a, 26a provided on the surface of the arcuate curved portion of the sheet material guide plate 26 to the conveying roller 16 respectively.
And is in contact with the roller surface, and is rotated by the rotational drive of the transport roller 16.

Reference numeral 15 denotes a platen bar which is arranged on the left side surface of the conveying roller 16 so as to be close to the conveying roller 16 and substantially parallel to the roller 16.

Reference numeral 11 denotes a reciprocating carriage, which is reciprocated in parallel with the platen bar 15 by a guide rail and a driving means (not shown). A recording head 12 and an ink ribbon cassette 13 are mounted on the carriage 11, and the recording head 12 faces the platen bar 15 with the ink ribbon 14 inside.

When the feeding roller 9 is driven to rotate in the clockwise direction of the arrow, the feeding force acts on the uppermost sheet material of the stacked sheet material 5 on the base 6 to cause the leading end of the uppermost sheet material. Both side corners ride on the upper side of the separating claw 7 and
By removing the sheet from the uppermost sheet material, only the uppermost sheet material is separated and guided from the table 6 to the surface of the guide plate 26 so that the conveying roller 16
And is fed toward the pressure contact nip portion with the first pinch roller 17A.

The feeding sheet material 5 is bridged by the conveying roller 16 and the first pinch roller 17A, guided by the inner surface of the arc portion of the guide plate 26 and conveyed along the lower surface of the conveying roller 16, and further the conveying roller. 16 and the second pinch roller 17B are interlocked and conveyed to the left side surface of the conveyance roller 16 so that the leading edge side of the sheet material enters between the plantain bar 15 and the ink ribbon 14.

When the entering amount becomes a predetermined value, the transport roller 1
The rotation of 6 is switched to the intermittent rotation drive control that intermittently conveys the sheet material in units of printing one line, and the reciprocating movement drive control of the carriage 11, the head down / head up control of the recording head 12, the ink ribbon feeding control, and the like are performed. The recording process for the feeding sheet material 5 is sequentially executed line by line by being relatedly executed by a recording control circuit (not shown).

For the purpose of driving the feeding roller 9, a method is often used in which the feeding roller 9 is driven in conjunction with a feeding motor (not shown) for driving the feeding roller 16 for reasons such as cost reduction. In this case, a clutch is provided between the feeding roller 9 and the conveyance motor to switch the drive. The simplest method is to switch the clutch by rotating the carry motor in the direction opposite to that at the time of feeding.

In the case of such a method, when the conveyance motor is driven in the normal direction by the paper feed start signal, the normal rotation driving force is transmitted to the feeding roller 9 via the clutch and the roller 9 feeds the sheet material. The uppermost sheet material of the stacked sheet material 5 is separated and fed one by one by rotating in the direction. The transport roller 16 is also driven to rotate in the sheet material transport direction.

Feeding sheet material 5 by rotation of feeding roller 9
The leading end of the conveyance roller 16 and the first pinch roller 17A
After reaching the pressure contact nip portion with and further fed by a predetermined length through the pressure contact nip portion, the conveyance motor is switched to the reverse rotation drive and controlled.

The reverse rotation of the transport motor disconnects the clutch connection between the motor and the feed roller 9, and the feed roller 9 is stopped. The conveying roller 16 is driven to rotate in the opposite direction Q to the conveying direction of the sheet material, and the leading end portion of the sheet material is fed by a predetermined length through a pressure contact nip portion between the conveying roller 16 and the first pinch roller 17A. Is conveyed back and the leading edge of the sheet material comes out of the pressure contact nip portion of the rollers 16 and 17A.

By this return conveyance of the leading end portion of the sheet material, the stiffness of the sheet material is increased in the sheet material portion between the pressure contact nip portion between the feeding roller 9 in the rotation stopped state, the conveying roller 16 and the first pinch roller 17A. A flexible loop is formed against the rigidity (rigidity) as shown by the solid line.

By forming such a bending loop of the sheet material, the bending reaction force pushes the leading edge of the sheet material into the pressure contact nip portion between the conveying roller 16 and the first pinch roller 17A, and the sheet material 5 is supplied. Even when the sheet is originally fed obliquely from the side of the feeding roller 9, the leading edge side of the sheet material can be aligned parallel to the longitudinal direction of the feeding roller 16.

Then, the conveying motor is switched back to the normal rotation driving mode again, so that the above-described pressure contact nip portion between the conveying roller 16 rotated in the sheet material conveying direction P and the first pinch roller 17A in pressure contact with the conveying roller 16 is formed. The leading edge of the conveyor roller 16
The sheet material 5 parallelized (obliquely taken) in the longitudinal direction of the sheet re-enters, and the sheet material 5 is intermediately conveyed to the recording unit 12 without skewing.

[0020]

However, in such a sheet material feeding apparatus, the stiffness of the sheet material is increased by changing the type of the sheet material 5 used or the temperature and humidity inside the apparatus. At this time, when the transport roller 16 is reversely rotated, the stiffness of the sheet material portion between the feed roller 9 and the transport roller 16 in the rotation stopped state against the sheet material return movement force by the reverse rotation roller 16. May result in a situation of overcoming.

In such a case, the conveyance roller 16 and the first
When the sheet material is moved back into the press nip portion with the pinch roller 17A and slipped between the sheet material front end portion and the reverse rotation conveyance roller 16, the sheet material is not moved back. The skewing of the sheet material is not performed based on the loop formation of the sheet material, and a roller mark is attached to the surface of the sheet material due to the slip of the reverse rotation conveyance roller 16, and the sheet material is damaged.

When the sheet is stiff or when the sheet is set diagonally and is fed to the apparatus in a skewed state, the loop formed during the reverse rotation operation of the transport rollers is not uniform or the transport is performed. The pressure contact nip portion between the roller 16 and the first pinch roller 17A may not be uniformly pressed on the left and right sides, and skew may remain.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems of the prior art and to provide a sheet material feeding device capable of preventing skewing and an image forming apparatus using the same.

[0024]

SUMMARY OF THE INVENTION The present invention is a sheet material feeding device characterized by the following configurations.

(1) Sheet material accommodating section, sheet material feeding means for feeding the sheet material in contact with the sheet material in the sheet material accommodating section, and sheet material for driving the sheet material feeding means In a sheet material feeding device having a feeding driving means,
When a force is applied between the sheet material feeding drive means and the sheet material feeding means in the direction in which the sheet material feeding means feeds the sheet material, a substantial braking load is applied to the sheet material feeding means. The sheet material feeding device is characterized in that drive control means is provided for applying a braking load while allowing a certain amount of reverse rotation when a force is applied in the opposite direction.

(2) The braking force of the drive control means is smaller than the sheet material conveying force of the sheet material conveying means for intermediately conveying the sheet material fed by the sheet material feeding means, and the sheet material feeding means The sheet material feeding device according to (1), wherein the force required to feed the sheet material is larger than that of the sheet material.

(3) The sheet material feeding device as described in the item (1), characterized in that it has means for variably controlling the braking force of the drive control means.

(4) The sheet material feeding device as described in any one of (1), (2), and (3), wherein the drive control means is a torque limiter.

(5) The sheet material feeding device as described in (1) or (2), characterized in that the sheet material feeding means is a rotating body whose rotation is controlled.

(6) Sheet material accommodating portion, sheet material feeding means for feeding the sheet material in contact with the sheet material in the sheet material accommodating portion, and sheet material for driving the sheet material feeding means In a sheet material feeding device having a feeding driving means,
Between the sheet material feeding drive means and the sheet material feeding means, there is provided a biasing means which operates only when a force is applied to the sheet material feeding means in a direction opposite to the sheet material feeding direction. A sheet material feeding device.

(7) The urging means stores the force received by the sheet material feeding means in the opposite direction to the sheet material feeding direction, and urges the sheet toward the sheet conveying means. (6) The sheet material feeding device as described above.

(8) The urging means is actuated when the sheet material feeding means receives a force equal to or more than a predetermined force in a direction opposite to the sheet material feeding direction. Sheet material feeding device.

(9) Sheet material accommodating portion, sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and sheet material for driving the sheet material feeding means In an image forming apparatus having a sheet feeding drive means and an image forming means for forming an image on a fed sheet material, a sheet material feeding means is provided between the sheet material feeding drive means and the sheet material feeding means. Does not apply a braking load to the sheet material feeding means when a force is applied in the sheet material feeding direction, and when a force is applied in the opposite direction, a braking force is applied while allowing some reverse rotation. An image forming apparatus comprising drive control means for providing the image forming apparatus.

(10) Sheet material accommodating portion, sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and sheet material for driving the sheet material feeding means In an image forming apparatus having a sheet feeding drive means and an image forming means for forming an image on a fed sheet material, between the sheet material feeding drive means and the sheet material feeding means,
An image forming apparatus comprising: an urging unit that operates only when a force is applied to the sheet material feeding unit in a direction opposite to the sheet material feeding direction.

[0035]

By providing the drive control means between the sheet material feeding means and the sheet material feeding driving means as described above, the skew feeding of the sheet material fed by the sheet material feeding means can be performed. Between the sheet material feeding means and the sheet material feeding means by controlling the sheet material feeding means and the sheet material feeding means that relays and conveys the sheet material fed by the sheet material feeding means. When forming a loop of sheet material against the waist strength of the sheet material, even if it is difficult or difficult to form a loop due to the strength of the feeding sheet material, the sheet material loop is formed. It is possible to make the sheet material returning movement force by the conveying means driven in reverse to the sheet material pressing force by the sheet material feeding means in the stopped state, and the sheet material is pressed against the sheet material pressing force. By easily returning and moving the sheet material Skew-up action is performed is modified lines posture.

Alternatively, the leading edge of the sheet material fed by the sheet material feeding means for forming the sheet material loop is received by the sheet material conveying means in the driving stop state or the reverse driving state, and the sheet material feeding means is continuously driven. Even when the sheet material is fed, the sheet material feeding means can apply the feeding force to the sheet material while appropriately reasonably sliding on the sheet material,
The skewed posture of the sheet material is corrected and the skew feeding action is performed.

Therefore, regardless of the type of sheet material used and the strength of the sheet material depending on the temperature and humidity conditions in the apparatus, the sheet material can always be reliably skewed and fed without damage. Become.

Further, the above-described effects are obtained when a force is applied between the sheet material feeding drive means and the sheet material feeding means in a direction opposite to the direction in which the sheet material feeding means feeds the sheet material. The same is true when the biasing means that acts only on the sheet material is provided, and the sheet material feeding means is driven without skewing the sheet material regardless of the type of sheet material or the method of setting the sheet material in the sheet material container. It can be reliably fed.

[0039]

【Example】

<Example 1> (Figs. 1 to 15) This example is a word processor to which a sheet material feeding device according to the present invention is applied.

(1) Schematic configuration of word processor (see FIG. 1)
4) FIG. 1 is an overall external perspective view of a word processor.

1 is a keyboard portion for inputting information,
Reference numeral 2 is a display device section mainly including a CRT for displaying information, 3 is a recording apparatus section (printer section) for printing information on a feeding sheet material, and 4 is a sheet as a recording medium to the recording apparatus section. A sheet material feeding device unit (hereinafter, referred to as a paper feeding device unit or a paper feeding device) that feeds a material (printing paper).

The recording device unit 3 is arranged above the display device unit 2, and the paper feeding device unit 4 is mounted above the recording device unit 3 and arranged. 2 and 3 are perspective cutaway views showing the interiors of the sheet feeding device unit 4 and the recording device unit 3, respectively.

FIG. 4 shows a sheet material feeding / conveying path from the sheet feeding device section 4 to the recording apparatus section 3, and this figure has already been described.

(2) Paper Feeding Device 4 (FIGS. 2, 4 to 6) The paper feeding device 4 feeds the uppermost sheet material of the sheet material 5 stacked and set on the sheet material mounting table 6 inclined forward and downward. And the separating claw 7 separates and feeds one sheet.

The sheet feeding roller 9 as sheet material feeding means has both ends of its roller shaft 9b rotatably supported by the frame 19 of the sheet material mounting table 6 at one end thereof, which will be described later. A drive transmission means 10 (FIGS. 2, 8 and 9) is provided, and the drive transmission means 10 and a conveyance motor 18 (FIG. 3), which will be described later, which is a sheet material conveyance drive means on the recording apparatus 3 side, are connected to each other. .

FIG. 5 shows the sheet material feeding roller 9 of the sheet feeding device 4.
FIG. 6 is a diagram showing a positional relationship between the sheet material conveying roller 16 on the side of the recording device 3 and a sheet feeding roller 9 in which one roller portion 9a is provided integrally with the shaft 9b at the longitudinal center of the shaft 9b.
The transport roller 16 has two left and right roller portions 16a and 16a integrally with the shaft 16b on the left side and the right side of the central portion of the shaft 16b.
The roller portion 9a of the feeding roller 9 is provided with the above-mentioned two left and right roller portions 16a, 16a of the conveying roller 16.
The corresponding positions are between.

(3) Skew removing operation of the feeding sheet material (see FIG. 5)
6) FIG. 5 shows a sheet material 5 that is separated and fed from the sheet feeding device section 4.
Is skewed and the conveying roller 16 and the first pinch roller 17A
-The state reached during 17A is shown.

In this figure, the sheet material 5 has a front end side and a right end side 5R.
Since the sheet material is obliquely fed in advance, the right end side 5R of the leading edge side has sufficiently reached and entered the corresponding pressure contact nip portion between the right transport roller 16 and the first pinch roller 17A. The left end side 5L of the tip end side is separated from the corresponding pressure contact nip portion between the left transport roller 16 and the first pinch roller 17A.

From this state, when the conveying roller 16 is reversely rotated in the direction Q opposite to the sheet material feeding direction for the clutch disengagement operation which will be described later, the leading edge side left end side 5L of the sheet material 5 and the left side conveying roller 16 and Since it is out of the pressure contact nip portion with the first pinch roller 17A, the return movement of the conveying roller 16 due to the reverse rotation does not occur, but the front end side right end side 5R of the sheet material 5 is the right conveying roller 16 and the first pinch roller. Since it has entered the pressure contact nip portion with 17A, it is subjected to the return movement A by the reverse rotation of the conveying roller 16 and the right side 5R of the leading edge side of the sheet material is moved back to move to the right side conveying roller 16 and the first conveying roller 16. It comes off from the pressure contact nip portion of the pinch roller 17A.

In this case, when the sheet material 5 has a low stiffness, the bending loop of the sheet material between the feeding roller 9 and the conveying roller 16 by the return movement A on the right end side 5R of the leading end side. 5a is formed, and the bending reaction force causes the sheet material 5
The leading side of the conveyance roller 1 on the left side is as shown by the chain double-dashed line 5b.
6 and the pressure contact nip portion of the first pinch roller 17A and the pressure contact nip portion of the right conveyance roller 16 and the first pinch roller 17A.

That is, the leading end side of the sheet material 5 skew-fed is aligned in parallel with the longitudinal direction of the left and right conveying rollers 16. Therefore, the transport roller 16 is rotated forward P
At this time, the sheet material 5 is conveyed to the above-mentioned recording unit (printing unit) 12 without skewing.

When the sheet material 5 has a high stiffness, the sheet material 5 is returned by the reverse movement A of the sheet material 5 by the reverse rotation Q of the conveying roller 16 on the right end side 5R of the leading edge side. 6 is rotated counterclockwise around the contact portion with 9 and the right end side 5R of the leading edge side of the sheet material 5 comes from the pressure contact nip portion between the right conveying roller 26 and the first pinch roller 17A. It rotates until it comes off and does not receive the return movement force A. As a result, the leading edge of the sheet material 5 extends over the entire length thereof, as shown by a two-dot chain line 5b in FIG. 6, in a pressure contact nip portion between the left conveying roller 16 and the first pinch roller 17A, and the right conveying roller 16 and the first nipping portion. The pinch rollers 17A come into contact with the pressure contact nip portions. That is, also in this case, the leading end side of the skew-fed sheet material 5 is aligned in parallel with the longitudinal direction of the left and right conveying rollers 16. Therefore, when the conveying roller 16 is rotated forward P next time, the sheet material 5 is conveyed to the recording unit 12 without skewing.

In the case of FIG. 6, if the sheet material 5 does not rotate about the feeding roller 9 in the C direction,
The conveyance roller 16 on the right side is the right end side 5R of the leading edge side of the sheet material 5.
And the first pinch roller 17A is not moved back from the pressure contact nip portion, skew correction is not performed, and the sheet material portion and the reverse-rotating transport roller 16 slip and damage the sheet material portion. there's a possibility that.

C with the feeding roller 9 at the center of the sheet material 5
In order to generate the rotation in the direction, the feeding roller 9 is rotated in the direction opposite to the sheet material feeding direction, or the sheet is applied with a force stronger than the pressing contact frictional force between the feeding roller 9 and the sheet material 5. The material 5 needs to be returned and moved A by the reverse rotation of the transport roller 16.

When the sheet material 5 is moved back by a force stronger than the pressure contact frictional force between the latter feeding roller 9 and the sheet material 5, the frictional force is the pressing force between the feeding roller 9 and the sheet material 5. It is determined by the friction coefficient of the feeding roller 9, and the pressing force and the friction coefficient are determined by the force required to separate and feed one sheet material 5.

Normally, the pressing force between the feeding roller 9 and the sheet material 5 is 200 to 500 g, and the friction coefficient of the feeding roller 9 is 1 to
It is set to 1.5, and if the pressing force is weak, it is not possible to separate and feed one sheet material, or if it is strong, on the contrary, if it is strong, two or more sheet materials are fed at once, so-called double feeding occurs. there is a possibility.

In the feeding roller 9 as the feeding means having the pressing force and the friction coefficient thus determined, the sheet material returning movement force by the reverse rotation of the conveying roller 16 resists the friction force and the sheet material. Is difficult to rotate in the C direction, and if the rigidity of the sheet material 5 is strong, the sheet material loop 5a between the feeding roller 9 and the conveying roller 16 as shown in FIG. The roller 16 and the sheet material portion slip between the rotated conveying roller 16 and the pinch roller 17A.

Therefore, since the pressing force and the friction coefficient cannot be reduced as described above, when the sheet material 5 is stiff, the sheet material 5 is caused to rotate in the direction C as shown in FIG. Therefore, it is necessary to rotate the feeding roller 9 in the direction opposite to the sheet material feeding direction.

(4) Clutch (FIGS. 8-10) Next, a clutch for transmitting / disconnecting power from the transport motor 18 (FIG. 3) to the feeding roller 9 will be described.

The one end of the shaft 9b of the feeding roller 9 is shown in FIG.
As shown in FIG. 9, the paper feed gear 1 which constitutes the drive transmission means 10.
0a, a clutch 10b, a clutch gear 10c and the like are provided.

The paper feed gear 10a is concentrically and integrally fixed to the shaft 9b, the clutch 10b is a cylindrical member which is concentrically and rotatably supported by the shaft 9b, and the clutch gear 10c is also concentrically and freely rotated by the shaft 9b. Supported by. The clutch 10b is located concentrically outside the paper feed gear 10a.

A clutch pawl 10d is swingably provided on the side surface of the clutch gear 10c on the clutch 10b side. When the clutch gear 10c rotates, the tip of the clutch pawl 10d slides on the outer periphery of the tubular clutch 10b. . The clutch pawl 10d is constantly urged by a spring (not shown) to rotate toward the clutch 10b around the support shaft, and has a degree of freedom that allows it to slide to some extent in the axial direction of the support shaft.

FIG. 8 shows the clutch-on state, in which the notch hole 10 formed on the outer periphery of the clutch 10b.
The tip portion of the clutch claw 10d has fallen into e and is engaged with the paper feed gear 10a. In this state, when the forward rotation force of the carry motor 18 is transmitted to the clutch gear 10c via the relay gear train G (only the last one is shown in the figure), the rotation of the clutch gear 10c is rotated. The sheet feeding roller 9 rotates in the sheet material feeding direction indicated by the arrow.

FIG. 9 shows a clutch-off state in which the clutch pawl 10d is disengaged from the paper feed gear 10a by the reverse drive of the carry motor 18.

FIG. 10A is a development view of the circumferential surface of the clutch 10b on which the clutch pawl 10d slides, and FIG. 10B.
(C) is a sectional view taken along line BB and line CC of FIG. In this figure, there are stoppers HP1 and HP2 on the peripheral surface of the clutch 10b, and S1 indicates the cutout hole 10e.

There is a step boundary line of La and Lb at the boundary between the region SHP1 on the HP1 side and the region SHP2 on the HP2 side.
When the clutch pawl 10d moves from HP1 to HP2, it moves HP1 → Lb → HP2, and when it moves from HP2 to HP1, it moves HP2 → La → HP1.

The direction in which the clutch claw 10d moves from HP2 to HP1 is the direction in which the feed roller 9 performs forward feeding of the sheet material, and the direction in which it moves from HP1 to HP2 is in the reverse feeding direction. 8-10, the clutch pawl 10
Even if d is at an arbitrary position, an initialization operation is performed to surely insert the clutch 10b into the cutout hole S1, and the clutch pawl 10d moves to HP1. The distance from HP1 to S1 is constant (this example prints 4 lines).
If the clutch pawl 10d is located at P1, it is easy to surely move it to S1.

In the initialization operation, the clutch claw 10d is S
1 and the clutch claw 10d is moved in the region surrounded by S1 and Ld in the HP1 direction.
Since d is inserted into S1 and the clutch is turned on, the clutch claw 10d is initially moved to HP2 in order to avoid this.

The clutch pawl 10d is SHP2 → HP1.
Since it is reliably moved to, the initialization operation can be all performed by moving the clutch claw 10d to the HP2 side and then moving it to HP1.

By rotating the carry motor 18 forward and backward in this way, it becomes possible to switch the drive transmission to the feeding roller 9.

(5) Torque limiter (Fig. 8 ・ 9 ・ 11 ・
12) 9c is a shaft tightening spring as a drive control means (torque limiter) externally fitted to one end of the shaft 9b of the feeding roller 9. One end 9c ₁ (FIGS. 11 and 12) of the spring 9c is fixed by being sandwiched between two protrusions 19a provided on the frame 19.

The spring 9c as the torque limiter
Means that when a force is applied to the feeding roller 9 in the sheet feeding forward direction e (FIG. 8 · 11), the feeding roller 9 is allowed to rotate in the direction e without any load, and conversely, the feeding roller 9 is rotated. When a force is applied to the sheet 9 in the reverse direction f (FIG. 12), the inner diameter of the spring 9c becomes smaller, and the shaft 9b is tightened to restrict the rotation of the feeding roller 9 in the reverse direction. do.

The force with which the spring 9c tightens the shaft 9b is greater than the maximum feeding force of the feeding roller 9 when the sheet material 5 is separated and fed one by one, and the feeding roller 16 and the pinch roller 17 are used.
It is smaller than the sheet material conveying force of A · 17B.

Reference numeral 9d is a clutch lever as a means for changing the operating force of the torque limiter depending on the type of sheet material used and the temperature and humidity inside the apparatus.

This clutch lever 9d is used for the feeding roller shaft 9
b is rotatably supported, and the tip side of the lever 9d is an arc gear 9d ₁ centered on the shaft 9b, and this clutch lever 9d is a gear 9f pivotally attached to the frame 19.
Is engaged with. The gear 9f is controlled in forward / reverse rotation angle by a clutch motor (not shown), and the clutch lever 9d swings forward / reversely around the shaft 9b in association with forward / reverse rotation of the gear 9f. This is the clutch lever 9d are planted the projections 9e against the other end 9c ₂ of the tightening spring 9c as the torque limiter.

The projecting portion 9e receives the other end portion 9c ₂ of the spring 9c which is rotated when the rotational force in the sheet feeding reverse direction f (FIG. 12) is applied to the feeding roller 9, and the other portions. The rotation amount of the end portion 9c ₂ is restricted to prevent the inner diameter of the spring 9c from becoming smaller. That is, it acts to limit the force of tightening the shaft 9b of the spring 9c. When the clutch lever 9d is rotationally controlled, the spring 9 of the protrusion 9e
By changing the position of c with respect to the other end 9c _2, it becomes possible to control the inner diameter of the spring 9c, that is, the force for tightening the shaft 9b of the spring 9c, whereby the feeding roller 9 is made to move the sheet material. The reverse rotation force can be changed by the conveyance force of.

Sheet material 5 fed by feeding roller 9
Of the sheet material 5 is conveyed by the leading end of the sheet material 5 after passing over between the conveying roller 16 and the first pinch roller 17A pressed against the conveying roller 16 and further rotating the feeding roller 9 for driving. Roller 16 and pinch roller 17A
When it is rotated in the reverse direction until it returns to the position between, the reverse rotation of the feeding roller 9 is prevented by the operation of the torque limiter 9c attached to the shaft 9b of the feeding roller 9, and the sheet material 5 is shown by the solid line in FIG. As described above, the portion between the transport roller 16 and the feeding roller 9 is in a loop state.

By forming such a loop, the sheet material 5
The leading edge of the sheet material 5 is the conveying roller 1 due to the strength of its own waist.
6 is pressed against the pressure contact nip portion between the pinch roller 17A,
The pressing force causes the leading edge of the sheet material to move to the conveyance roller 1.
6 can be aligned parallel to the longitudinal direction, and the sheet material can be fed to the conveying roller without skewing.

Using the diagram of the relationship between the thickness t of the sheet material 5 and the load on the feeding roller 9 during loop formation shown in FIG.
The operation of the torque limiter will be described.

Here, the case where the sheet material 5 is plain paper and a postcard which are commonly used will be described. Normally, the thickness of plain paper is 40 to 100 μm, and the thickness of postcards is 2.
Since it is 30 μm and the postcard is 2 to 5 times thicker, the strength of the waist is also significantly different.

Further, the strength of the waist of the sheet material changes depending on the humidity, and the two solid lines in FIG. 13 indicate the feeding roller 9 depending on the strength of the waist when a loop is formed at a humidity of 10% and a humidity of 80%.
It shows the change in load applied to. Generally, the lower the humidity, the greater the load, and the thicker the sheet material, the greater the load. The rotational load of the feeding roller 9 in the direction opposite to the sheet material feeding direction (not rotating below this load) needs to be larger than the separating force of the sheet material. Therefore, normally, the dashed line (a) in FIG. It is set to the load indicated by. In this case, since the load on plain paper is always smaller than the one-dot broken line (a) regardless of humidity, the conveyance roller 16
Reverse to make a loop.

However, in the case of a postcard, the carrying roller 16 is used.
Even if it is reversed, a loop can be made in the range indicated by the solid line (d), but it cannot be made in the range indicated by (c) (broken line in FIG. 4).
The feeding roller 9 rotates in the reverse direction or slips with the feeding roller 9 to cause an unstable state in which a trace of the feeding roller remains on the sheet material.

Therefore, in the case of a postcard, the operating force of the torque limiter 9c is reduced to the one-dot broken line (e) so that the conveying force of the sheet conveyed in the reverse direction is reduced by the torque limiter 9.
Since the feeding roller 9 can be always rotated in the reverse direction by overcoming the operating force of c, no trace of the feeding roller remains on the sheet material.

There is also a method in which the operating force of the torque limiter 9c is made larger than the one-dot broken line (a) to always form a loop in the case of a postcard, but in this method, the postcard is bent or the device There is a problem such as the need to increase the strength, which is not appropriate.

As described above, since the stiffness of the sheet material itself is changed by the influence of the type of sheet material and the temperature and humidity of the apparatus, the conveying force of the above-mentioned reversely conveyed sheet material also changes.
Therefore, by changing the position of the protrusion 9e depending on the type of sheet material and the temperature and humidity of the apparatus, the spring force of the tightening spring 9c as a torque limiter is reversed so that the feeding roller is reversed with a force smaller than the above-described reverse conveying force. Can be set.

In this embodiment, the case where the number of the roller portions 9a of the feeding roller 9 is one has been described, but when the number of the feeding roller portions 9a is two as shown in FIG. 7, for example, a pair of the feeding roller portions is used. 9
The center of the a. 9a and the center of the pair of conveying roller portions 16a, 16a are provided so as to be substantially on the same line in the sheet material feeding direction, and the above-mentioned torque limiter is attached to each of the two feeding rollers. It is possible to carry out the same method as in the case of one feeding roller unit.

(6) Temperature / Humidity Detecting Means A temperature / humidity detecting means (not shown) for detecting temperature / humidity in the paper feeding apparatus and the recording apparatus using the paper feeding apparatus is attached at a proper position in the apparatus. The temperature detecting means is a temperature thermistor or the like, and the humidity detecting means is an electrostatic capacitance type humidity sensitive element or the like. The temperature / humidity detecting means detects the temperature / humidity in the apparatus, and automatically changes the amount of electricity to the recording head 12 according to the temperature / humidity, or automatically controls the clutch motor for controlling the torque limiter 9c. It becomes possible to do it.

(7) Regarding the recording device 3.

In FIG. 3, the carriage 11 is slidably attached to the guide shaft 20, and both ends of the guide shaft 20 are fixed to the recording frame 21. Further, the carriage motor 2 is attached to the recording frame 21.
A driven pulley, not shown, which is interlocked with the driving pulley, is attached to the carriage 11. A timing belt 23 stretched between the pulleys is connected to the carriage 11. As a result, when the carriage motor 22 rotates forward and backward, the carriage 11 reciprocates along the guide shaft 20.

At a predetermined position of the carriage 11, the take-up core 13c of the ink ribbon cassette 13 is fitted, and the ink ribbon 14 is wound around the take-up core by rotating the carriage 11 in the direction of arrow b. A take-up shaft 24 for taking up is provided.

The ink ribbon cassette 13 has a supply core 13b and a winding core 13c rotatably housed in a container 13a, and an ink ribbon 14 is wound around the supply core 13b. The ink ribbon 14 is once exposed from the supply core 13b in the recess 13d formed in the container 13a, and is wound around the winding core 13c.

The ink ribbon 14 is a long film coated with a heat transferable (heat melting, heat softening, heat subliming, etc.) ink. Also, the ink ribbon cassette 1
3 is locked by a locking protrusion 11 a provided on the carriage 11 so that the carriage 3 can be loaded on the carriage 11. still,
The winding shaft 24 is fitted to the winding core 13c when the cassette 13 is loaded on the carriage 11, and the winding core 13c is rotated by the rotation of the winding shaft 24.

The recording means is the thermal recording head 12 in this embodiment.
The plurality of heating elements that generate heat when energized are arranged in a line on the head substrate. The recording head 12
3 is mounted on the carriage 11 as shown in FIG. 3, and is configured so as to be positioned in the container recess 13d when the ink ribbon cassette 13 is loaded in the carriage 11.

The recording head 12 is constructed so as to move up and down in the direction of arrow a by a biasing means such as a solenoid (not shown).
The ink application surface of the ink ribbon 14 is brought into pressure contact with the sheet material 5 supported by, and the ink ribbon 14 is separated from the sheet material 5 when the head is raised.

Therefore, the carriage 11 is moved in the direction of the arrow b with the recording head 12 being head down,
When the recording head 12 is selectively heated in synchronization with the running, the ink melted by the heat is transferred and recorded on the sheet material 5.

When recording, the ink ribbon 14 unwound from the supply core 13b is wound around the winding core 13c by the rotation of the winding shaft 24.

When one-line recording is completed in this way, the recording head 12 heads up, the carriage 11 returns to the home position, and the sheet material 5 is conveyed by one line in the direction of arrow c in FIG.

The transport means 16 for transporting the sheet material 5 comprises the transport roller 16a and the pinch roller 17 in pressure contact with the transport roller 16a as described above, and the transport motor 16 is connected to the transport roller 16 via the drive transmission gear train. Become.

Therefore, when the carry motor 18 is driven, the carry roller 16 rotates, the sheet material 5 fed from the paper feeding device 4 is carried by U-turn along the peripheral surface of the carry roller 16, and the platen 15 and the ink ribbon are carried. It is conveyed in the direction of arrow c through 14

(8) Control Means (FIG. 14) Next, the control means for driving and controlling the paper feeding device 4 and the recording device 3 using this paper feeding device will be described.

FIG. 14 is a block diagram of the control system. This block diagram shows only the connection relationship of each block, and detailed control lines are omitted. The portion surrounded by the broken line is the CPU unit.

The CPU 30 is a central processing unit, and includes a ROM 31 and a floppy disk driver 32 described later.
The program and various data are read from (FIG. 1) and the like, necessary calculations and judgments are performed, and various controls are performed.

The ROM 31 is a read-only memory,
Various programs for operating the CPU 30, character codes, dot patterns (character generator; CG)
It stores various data required for recording.

The RAM 33 is a read / write memory, and stores various data input from the working area in which the CPU 30 temporarily stores the data in the instruction and the operation result, the keyboard 1, the external interface section 37, the floppy disk driver 32, and the like. It consists of a buffer area for storing documents and a text area for storing documents.

The CPU unit is also connected to the printer unit 37 via the recording head driver 34, the motor driver 35, and the detecting section 36.

The recording head driver 34 drives the recording head 12 provided in the printer unit 3 under the control of the CPU 30, and the motor driver 35 controls the CP.
Under the control of U30, the conveyance motor 18 (FIG. 3), the carriage motor 22 (the same), the clutch motor of the sheet feeding device 4, and the like are driven.

The detection section 36 transmits detection information to the CPU 30 from a ribbon sensor provided in the printer unit 3 for detecting the presence or absence of a ribbon, a temperature / humidity detection sensor for detecting temperature / humidity in the apparatus, or the like. The power source 38 is a power source V _H for driving the recording head 12, a power source V _M for driving the carry motor 18, the carriage motor 22, a clutch motor, etc., a power source V _FDD for driving the floppy disk driver 32, and a power source V for other logic circuits. Supply control of _CC .
The controller 39 transfers the print data of the print head 12 under the control of the CPU 30, and drives the drive power source V.
_{The H} voltage and current are changed and various controls are performed.

A keyboard 1 for inputting various data required for recording and editing is connected to the CPU unit via a keyboard connector (KBC) 40.

Further, the CPU unit is connected to a display section 2 composed of a CRT for displaying data and various information input from the keyboard 1 via a CRT connector (CRTC) 41. The display unit 2 may have another structure such as a liquid crystal display instead of the CRT.

Further, a floppy disk driver 32 is connected to the CPU unit via a floppy disk driver connector (FDDC) 42. A hard disk or an external RAM may be connected instead of the floppy disk.

The CPU unit is an RS232C for controlling the recording device 3 by an external control device and communicating with an external device via an interface connector (IFC) 43.
It is also possible to connect interfaces such as 44, Centronics 45, and modem 46.

(9) Control Procedure (FIG. 15) Next, the control procedure when printing is performed by the sheet feeding device 4 and the recording device 3 having the above-described configuration will be described with reference to the flowchart of FIG.

When the recording command is designated, the recording apparatus 3 detects the temperature and humidity inside the apparatus by the temperature and humidity detecting means, and further detects the type of the sheet material input from the keyboard 1 or the like. Optimum torque limiter 9c for the sheet material used by judging the information of the sheet material detected by
The rotational position of the clutch lever 9d that obtains the spring force is determined (steps S1, S2, S3).

The clutch motor is driven to drive the clutch lever 9d to this determined position (at step S4).

After that, for conveyance, the motor is rotated by 10 reverse rotations and 10 normal rotations, and the above-mentioned clutch pawl 10d is turned to H level.
It is moved to P1 (FIG. 10) (at step S5).

Next, the carry motor 18 is rotated in the opposite direction for four rows to move the clutch pawl 10d from HP1 to the hole S1 (10).
e), and the clutch is turned on (FIG. 8) (at step S6).

After that, the feeding roller 9 is rotated in the forward direction to rotate the feeding roller 9, and the sheet material is fed to the recording apparatus 3 (at step S7).

When the leading edge of the sheet material reaches a position beyond the distance between the conveying roller 16 and the first pinch roller 17A, the driving of the conveying motor is stopped (S8).

Next, the conveyance motor 18 is reversely driven to reversely rotate the conveyance roller 16 (at step S9), and the leading end of the sheet material 5 returns to a position between the conveyance roller 16 and the first pinch roller 17A. At that time, the drive of the carry motor is stopped (at step S10).

Further, the carry motor 18 is driven in the normal direction to carry the sheet material until the recording head 12 faces the position (printing portion) where the recording head 12 prints on the sheet material, and then the drive of the carry motor is stopped (the same). S11, S12, S13).

As a result, the sheet material can be conveyed to a desired position for recording on the sheet material by the recording head.

<Embodiment 2> (FIGS. 16 to 20) In this embodiment, in the above-described Embodiment 1, a feeding roller 9 as a sheet material feeding means, and a feeding driving means 10 (feeding gear 1
0a, clutch 10b, clutch gear 10c, etc.) as a drive control means provided as a torque limiter mechanism 9a.
Instead of 9c, 9d, 9e, and 9f (Figs. 8, 9, 11, and 12), as shown in Figs. 16 to 19, between the feeding roller 9 as the feeding unit and the feeding driving unit 10, A force accumulating mechanism 9g to 9j is provided as an urging unit that operates only when the feeding roller 9 receives a force in a direction f opposite to the sheet feeding direction e.

Other configurations such as the word processor configuration, the sheet feeding device configuration, the skew feeding operation, the clutch, the recording device, and the control means are the same as those in the first embodiment.

(1) Energizing means (accumulation mechanism 9g to 9j) A spring holder 9h is attached to one end of the shaft 9b of the feeding roller 9 via a one-way bearing 9i, and the feeding roller 9 feeds the sheet material. Direction f opposite to direction e (Fig. 19)
When rotated to, the one-way bearing 9d causes the spring holder 9h to rotate in the f direction. Further, one end of a spring 9g is fixed to a pin 9j that is integral with the spring holder 9h, and the other end is fixed to a protrusion 19b of the frame 19.

FIG. 18 shows a state in which the feeding roller 9 is rotationally driven (forward feeding) in the sheet feeding direction e, and at this time, the feeding roller 9 is rotated with respect to the rotation direction. It does not receive the force from the power storage mechanisms 9g to 9j.

FIG. 19 shows a state in which the feeding roller 9 is rotating (reverse feeding) in the direction f opposite to the feeding direction of the sheet material. At this time, the spring holder 9h moves the unidirectional bearing 9i. The spring 9g is charged by rotating in the direction f against the spring 9g, and biases the feeding roller 9 in the forward direction e.

Therefore, if the force by which the sheet material 5 moves in the direction opposite to the feeding direction by the reverse rotation Q of the conveying roller 16 is larger than the spring force, the feeding roller 9 can be rotated in the reverse direction. Further, even if the sheet material having a weak stiffness, that is, the returning force in the direction f opposite to the feeding direction e is weak, the feeding roller 9 can be rotated in the reverse direction f by weakening the spring force. That is, if the spring force is set to be stronger than the returning force of the sheet material, the feeding roller 9 does not rotate in the reverse direction, and if it is set to be weak, the feeding roller 9 can rotate in the reverse direction.

When the conveying roller 16 is reversely rotated in the direction Q opposite to the feeding direction P for the above-mentioned clutch disengagement operation from the state of FIG. 5 described above, the leading edge side 5L of the sheet 5 is the left side conveying roller. 16 is out of the pressure nip portion between the first pinch roller 17A and the first pinch roller 17A, no reverse movement occurs due to the reverse rotation of the conveying roller 16, but the right end side 5R of the leading edge of the sheet material 5 and the right conveying roller 16 Since it has entered the pressure contact nip portion with the pinch roller 17A, the right end side 5R of the leading edge side of the sheet material is moved back by the action of the returning movement A by the reverse rotation of the conveying roller 16 and the right conveying roller 16 It comes off from the pressure contact nip portion of the first pinch roller 17A.

At the time of this returning movement, the sheet material 5 causes the feeding roller 9 to rotate in the opposite direction, and at the same time, the spring 9g is charged. When the reverse rotation of the conveying rollers 16 is stopped in this state, the leading edge of the sheet material 5 abuts on the pressure contact nip portion between the conveying roller 16 and the first pinch roller 17A by the spring force, and the left and right conveying rollers 16 are longitudinally moved. Will be aligned parallel to.

Therefore, next, the transport roller 16 rotates forward P
At this time, the sheet material 5 is conveyed to the recording unit 12 described above without skewing. In this way, the skew of the sheet material 5 can be removed by rotating the feeding roller 9 in the reverse direction.

(2) Control Procedure Next, the control procedure when printing is performed by the paper feeding device and the printing device having the above-mentioned configuration will be described with reference to the flowchart of FIG.

When a recording command is first designated (step S1), this recording apparatus rotates the carry motor 18 for 10 reverse rotations and 10 normal rotations to move the clutch pawl 10d to HP1 (FIG. 10). (Step S2).

Next, the carry motor 18 is rotated in the opposite direction for four rows to shift the clutch pawls 10d from HP1 to S1 (see FIG. 1).
0) to the clutch ON state (step S3).

Then, the feed motor 9 is driven to rotate in the forward direction to rotate the feeding roller 9 and feed the sheet material 5 to the recording apparatus (step 4).

When the leading edge of the sheet material reaches a position beyond the distance between the conveying roller 16 and the pinch roller 17A, the driving of the feeding motor and the conveying motor is stopped (step S5).

Next, the carry motor 18 is reversely driven to reversely rotate the carry roller 16 (step S
6) When the leading edge of the sheet material 5 returns to the position between the transport roller 16 and the pinch roller 17A, the transport motor 18
Is stopped (step S7).

Further, the carry motor 18 is driven in the normal direction to carry it until the recording head 12 faces the position for recording on the sheet material, and then the drive of the carry motor 18 is stopped (steps S8, S9, S10). .

As a result, the sheet material 5 is applied to the recording head 12
The sheet material 5 can be conveyed to a desired position for recording on.

<Modifications, etc.> (1) In Examples 1 and 2, the serial type thermal transfer type apparatus was illustrated, but the present invention can also be applied to a line type thermal transfer type, and the present invention is further applied. The recording method is not limited to the thermal transfer method, and the inkjet method,
It can be applied to various recording methods such as a wire dot method and a laser beam method.

(2) Further, as the sheet material conveying means of the recording apparatus, the method of winding the sheet material around the peripheral surface of the conveying roller has been exemplified, but the present invention is not limited to this, and only the conveying roller and the pinch roller pressure contact portion are used. Horizontal transport method to transport,
The present invention can also be applied to a belt transfer method in which a belt is used for transfer.

(3) Further, although the separating claw method has been exemplified as the sheet material separating means of the sheet feeding device, the present invention is not limited to this, a slope separating method for separating using a slope, and a friction force of a separating pad. It is also possible to apply to a separation pad system and the like for separating by utilizing.

(4) As a feeding method, after the sheet material is meshed between the feeding roller and the pinch roller, the feeding roller is reversely rotated to form a loop. However, the present invention is not limited to this. The conveying roller may be reversed while the feeding roller is being driven, or the method may be applied to a method of driving the feeding roller and then driving the conveying roller of the recording apparatus to reversely convey the sheet material.

(5) In the first embodiment, the clutch lever is driven by the motor, but the present invention is not limited to this, and a method of interlocking with the feeding drive means, a method of using a drive means such as a solenoid, etc. It can also be applied to a manual method and the like.

(6) In the second embodiment, the case where the spring 9g attached to the feeding roller has a constant charging force when the amount of backward movement of the sheet material 5 is constant has been described. For example, as shown in FIG. A spring lever 9k to which one end of a spring 9g is fixed is rotatably attached to the frame 19, and the spring lever 9k is g
It is possible to change the charging force of the spring 9g by rotating in the direction (direction to decrease the charging force) or in the direction h (direction to increase the charging force), and the strength of the waist of the sheet material 5 is changed. Even if the amount of reverse rotation changes, it is possible to always urge the sheet material 5 toward the conveying roller 16 with a constant force, or change the urging force depending on the strength of the waist of the sheet material 5.

The charging force of the spring 9g may be changed by an input from the keyboard 1, the type of the sheet material may be discriminated by a sensor or the like, or manually by a motor or the like.

[0146]

As described above, according to the sheet material conveying apparatus of the present invention, the sheet material is irrespective of the kind of the sheet material used and the stiffness of the sheet material due to the temperature and humidity conditions in the apparatus. It is possible to always reliably feed the skewed material without damaging the material.

[Brief description of drawings]

FIG. 1 is an external perspective view of an example of a word processor to which a sheet material feeding device according to the present invention is applied.

FIG. 2 is a cutaway perspective view of a sheet feeding device.

FIG. 3 is a cutaway perspective view of the recording apparatus.

FIG. 4 is a sheet material feeding / transporting path diagram from a paper feeding device to a recording device.

FIG. 5 is an explanatory view (1) of the skew feeding action of the feeding sheet material.

FIG. 6 is an explanatory view of the skew feeding action of the feeding sheet material (Part 2)

FIG. 7 is an explanatory diagram of the skew feeding action of the feeding sheet material (Part 3)

FIG. 8 is a partially cutaway perspective view of drive transmission means in a clutch-on state.

FIG. 9 is the same as above with the clutch off.

FIG. 10A is a development view of a clutch peripheral surface, and FIG.
(C) is a cross-sectional view taken along the lines BB and CC of FIG.

FIG. 11 is a side view showing the operation of the torque limiter (No. 1).

FIG. 12 is a side view showing the operation of the torque limiter (part 2).

FIG. 13 is a graph showing the relationship between the thickness of the sheet material and the load during loop formation.

FIG. 14 is a block diagram of a control system

FIG. 15 is a flowchart showing a sheet material feeding operation procedure.

FIG. 16 is a partially cutaway perspective view of drive transmission means in a clutch-on state of the second embodiment device.

FIG. 17 is the same as above with the clutch in the off state.

FIG. 18 is a side view showing the operation of the urging means (No. 1).

FIG. 19 is a side view showing the operation of the urging means (No. 2).

FIG. 20 is a flowchart showing a sheet material feeding operation procedure.

FIG. 21 is a side view showing the operation of the biasing means of another embodiment.

[Explanation of symbols]

1 keyboard 2 Display 3 recording devices 4 Paper feeder 5 Sheet material as recording medium 9 Feeding means (feeding roller) 9c Spring as drive control means (torque limiter) 9d clutch lever 9g-9j Energizing means (accumulation mechanism) 10 Feed drive transmission means 10b clutch 10d clutch claw 11 carriage 12 recording head 16 Conveying means (sheet material relaying conveying roller) 17 pinch rollers 18 Conveyor motor 22 Carriage motor 30 CPU 31 ROM 33 ROM 34 Recording head driver 35 motor driver 36 Detector

Claims (10)

[Claims] 1. A sheet material accommodating portion, a sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and a sheet material feeding means for driving the sheet material feeding means. In a sheet material feeding device having a feeding drive means, when a force is applied between the sheet material feeding drive means and the sheet material feeding means in a direction for feeding the sheet material, The sheet material feeding means is provided with a drive control means which substantially does not give a braking load to the sheet material feeding means and allows a certain amount of reverse rotation when a force is applied in the opposite direction to give a braking load. Sending device. 2. The braking force of the drive control means is smaller than the sheet material conveying force of the sheet material conveying means for intermediately conveying the sheet material fed by the sheet material feeding means, and the sheet material feeding means The sheet material feeding device according to claim 1, wherein a force required to feed the sheet material is larger than that required. 3. The sheet material feeding device according to claim 1, further comprising means for variably controlling the braking force of the drive control means. 4. The sheet material feeding device according to claim 1, wherein the drive control means is a torque limiter. 5. The sheet material feeding device according to claim 1, wherein the sheet material feeding means is a rotating body whose rotation is controlled. 6. A sheet material accommodating portion, sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and sheet material feeding means for driving the sheet material feeding means. In a sheet material feeding device having a feeding driving means, a force is applied between the sheet material feeding driving means and the sheet material feeding means in a direction opposite to a direction in which the sheet material feeding means feeds the sheet material. A sheet material feeding device, characterized in that it is provided with a biasing means that acts only when 7. The urging means is configured to store a force received by the sheet material feeding means in a direction opposite to a sheet feeding direction and urge the sheet to the sheet conveying means. The sheet material feeding device according to claim 6. 8. The urging means operates when the sheet material feeding means receives a force equal to or more than a predetermined force in a direction opposite to the sheet material feeding direction. Sheet material feeding device. 9. A sheet material accommodating portion, a sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and a sheet material feeding means for driving the sheet material feeding means. In an image forming apparatus having an image forming means for forming an image on a fed sheet material, a sheet material feeding means is provided between the sheet material feeding drive means and the sheet material feeding means. When a force is applied in the sheet material feeding direction, a braking load is not substantially applied to the sheet material feeding means, and when a force is applied in the opposite direction, a braking load is applied while allowing some reverse rotation. An image forming apparatus comprising drive control means. 10. A sheet material accommodating portion, sheet material feeding means for feeding the sheet material by feeding the sheet material in the sheet material accommodating portion, and sheet material feeding means for driving the sheet material feeding means. In an image forming apparatus having an image forming means for forming an image on a fed sheet material, a sheet material feeding means is provided between the sheet material feeding drive means and the sheet material feeding means. An image forming apparatus comprising: an urging unit that operates only when a force is applied in a direction opposite to a direction in which a sheet material is fed.