JP3305146B2 - Sheet material feeding device, recording device, and sheet material separating method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a recording device (printer) as an information output device in a word processor, a personal computer, and the like, an image forming apparatus such as a copying machine and a facsimile, and various other devices using sheet materials. , Sheet materials (printing paper, transfer paper, photosensitive paper, electrostatic recording paper, printing paper, OHP)
The present invention relates to a sheet material feeding device for feeding sheets, envelopes, postcards, sheet documents, and the like) to a sheet material processing unit such as a recording unit, a reading unit, and a processing unit, and a recording device including the sheet material feeding device.

[0002]

2. Description of the Related Art A sheet material feeding apparatus is required to have a function of reliably separating and feeding sheet materials one by one from a stacked sheet material.

Conventionally, a claw member is provided at a front end corner of a stacked sheet material, and when the sheet material is fed out by a feeding roller, only the uppermost sheet material bends and climbs over the claw member so that one sheet at a time. Although there is a separation type, it is not suitable for separating a sheet material that is not easily bent, for example, a stiff sheet material such as an envelope or a postcard.

Therefore, as a technique for separating sheet materials having different flexural elasticities by a single separating unit,
There is one described in JP-A-58-202228. This technique will be briefly described with reference to FIGS.

[0005] The sheet material loading table 301 on which the sheet material is loaded is urged upward by a spring 302, and the position of the uppermost sheet material is regulated by pressing claws 302 arranged near the left and right ends of the sheet material. Have been. Then, the feeding roller 303 is in contact with the uppermost sheet material, and feeds out by rotating.

A contact member 305 is provided on a reference surface 304 for regulating the position of the front end of the stacked sheet material. The contact member 305 is a plastic film or a metal spring plate having a predetermined bending elastic force. The sheet material sent out by the feed roller 303 comes into contact with the sheet material, so that an angle change occurs.

In this sheet feeding apparatus, for example, a sheet material having a small bending elastic modulus, such as a sheet material for a copying machine, is bent at the corners of the sheet material in the same manner as in a separation method using a claw member, so that a pressing claw 302 is provided. For thick paper such as envelopes and postcards that have a large flexural modulus, the sheet can be separated by slipping over the contact member at the leading end and sliding through the contact member. Are separated. In this manner, sheet materials having various flexural modulus can be separated.

Further, as shown in FIG. 14, a separation board 306 for cardboard may be provided on the reference surface side. In this case, the cardboard is separated by overcoming the separation plate 306 and bending the contact member.

Further, as a technique for separating a sheet using a member similar to the above-mentioned contact member, Japanese Patent Laid-Open No.
There is one disclosed in JP-A-193834. In this method, a sheet material loading table loaded with a sheet material is pressed against a feeding roller by a spring, and the sheet material is sent out by rotation of the feeding roller, and a contact member is arranged at a right angle to the feeding direction of the sheet material. The sheet material fed by the feeding roller is separated one by one by bending the contact member. According to this configuration, various sheet materials having different flexural modulus can be separated.

However, the sheet feeding apparatus as described above has the following problems. For example, when the elastic force of the contact member is set so as to stably feed a sheet material having a thickness of about a postcard, if the sheet material is to be fed thicker than the postcard, the feeding force of the feed roller causes the sheet material to be fed. When hitting against the contacting member, the contacting member is bent more than necessary because the elastic force of the sheet material is stronger than the postcard, and as a result, the frictional force between the sheet materials works strongly between the sheets, and two or less sheets are used. The sheet material easily gets over the contact member, and double feed such as double feed or triple feed occurs.

In order to prevent this double feeding, if the elastic force of the contacting member is increased or the height of the upper end is increased, when feeding postcards and sheet materials thinner than the postcards, the leading edge of the sheet material is reduced. The feeding roller may be broken, or the feeding force of the feeding roller may be less than the elastic force of the contact member, and the feeding roller may slip on the surface of the sheet material to cause a feeding defect.

As a technique for solving the problem of the separation effect that occurs when the elastic force of the sheet material is largely different as described above, there is a sheet material feeding apparatus described in Japanese Utility Model Publication No. 5-35944. This technique will be schematically described with reference to FIG.

This sheet material feeding device has a feeding roller 401 for feeding the sheet material, and a separating member for separating the sheet material S fed by the feeding roller 401 one by one. The member is provided with a first separation claw 402 having flexibility and a height suitable for separating thin thick paper, and a plurality of protrusions 404 on an upper end side of a paper side surface mainly performing separation of thick paper, In addition, a flexible second separating claw 403 whose upper end is slightly lower than the upper end of the first separating claw 402 is joined and fixed except for the upper part.

In the above configuration, the leading end of the first sheet material S fed by the feeding roller 401 is connected to the second separation claw 403.
(FIG. 15A), the second separation claw 403 is bent by losing the rigidity of the sheet material S, and then the front end of the sheet material S jumps up and climbs over the second separation claw 403. Further, the first separation claw 4 is returned while returning the first separation claw.
02 also gets over (FIG. 15 (b)). Second separation claw 40
3 returns vertically during that time, so that no more than two sheets are held by the second separation claw 403.

[0015]

However, even with the sheet feeding apparatus disclosed in Japanese Utility Model Publication No. 5-35944, the above problem cannot be surely solved.
That is, in this apparatus, the first and second separation claws are arranged, and the sheet material that cannot be separated by the second separation claw is removed by the first separation claw.
When the sheet materials have greatly different stiffness, the first separation claw portion is used as shown in FIG. 13 and FIG.
The same problem as shown in FIG. Therefore, this device has not been able to sufficiently solve the conventional problems.

Further, in recent years, a sheet material other than paper, such as a resin film having a low surface friction coefficient, is sometimes sent. In this case, the feeding force of the sheet feeding roller is greatly reduced. As a result, it is not possible to select an optimum material for the contact member and the separation claw in accordance therewith.

Therefore, at present, the range of the material and thickness of the sheet material to be separated is limited by the abutting member and the separation claw, and when separating other sheet materials, it is necessary to use another separation method. There is a problem that the apparatus becomes complicated and the cost increases.

The present invention has been made in view of the above-mentioned problems, and it is possible to reliably separate and supply a sheet material having a low surface friction coefficient or a sheet material having a large bending elasticity. It is an object to provide a sheet material feeding device.

[0019]

According to the present invention, there is provided a sheet material stacking means for stacking a plurality of sheet materials, a sheet material feeding means for feeding the sheet material stacked on the sheet material stacking means, and a sheet material feeding means. Separating means having a plate-like member for separating the sheet material one by one by the sheet material sent out by the feeding means is elastically bent and deformed by being hit by the sheet material, and The separating means may include a fulcrum changing means for changing a fulcrum of the plate-like member with respect to a direction in which the plate-like member is deformed.

[0020] In the present invention, the fulcrum changing means may be a first fulcrum imparting portion which is first contacted by at least the plate-shaped member being curved and deformed, and is contacted with the plate-shaped member by increasing the amount of the curved deformation. A second fulcrum providing unit.

[0021]

According to the above construction, the plate-like member is bent and deformed by the rigidity of the sheet material fed by the sheet material feeding means, and the sheet material is separated one by one as it passes over it. That is, the sheet is separated by the balance between the rigidity of the sheet material and the elastic force of the plate member. At this time, the fulcrum position of the plate member is changed according to the rigidity of the sheet material so that the elastic force of the plate member is optimized in accordance with the rigidity of the sheet material. Can widen the types of sheet materials that can be separated.

When the first and second fulcrum imparting portions are provided to separate a relatively rigid sheet material, the amount of bending deformation of the plate-like member is small, so that the first fulcrum imparting portion serves as a fulcrum. Is deformed to generate a relatively small elastic force to separate the sheet material, and when separating a relatively rigid sheet material, the amount of bending deformation of the plate-like member increases and the second
The plate member is deformed with the fulcrum providing portion as a fulcrum, and a relatively large elastic force is generated to separate the sheet material. in this case,
Since the amount of bending deformation of the plate-like member changes according to the rigidity of the sheet, the fulcrum position is automatically changed between the first and second fulcrum providing portions.

[0023]

1 and 2 show a first embodiment in which the present invention is applied to an ink jet printer using an ink jet system as a recording means. FIG. 1 is a schematic view showing the mechanism of the present apparatus, and FIG. It is sectional drawing of this apparatus.

In FIG. 2, a cover 1 is provided outside the main body of the apparatus.
And a lid 2 rotatable about a shaft 2a. The lid 2 also serves as a sheet material tray. The sheet material is inserted from an insertion port 1a provided in the cover 1 and is discharged from an insertion port 1b.
Is discharged from Inside the plurality of side plates 3 provided in the cover 1, a sheet material is urged toward the feed roller 9 (upward) by a spring 5 having one end fixed by a pin 6 around a shaft 4a. A table (sheet material loading means) 4;
A feeding roller (sheet material feeding means) 9 having a long radius portion capable of contacting the sheet material and a short radius portion not contacting the sheet material and fixed to the shaft 8; The driving cam 7 which rotates to engage with the follower portions 4b provided at the left and right ends of the sheet material loading table 4 to push the sheet material loading table 4 downward, and the sheet material fed by the feeding roller 9. The contact member (separating means) 1 is a separating member that separates the sheet material by causing an angle change due to the contact.
0, and a surface 11a in which the leading end of the sheet material separated by the contact member 10 is guided in an ascending direction, and the sheet material and the contact member 1 are guided by the surface 11a.
And a guide member 11 for separating the leading end of the zero.

The contact member 10 has a plurality of fulcrums 11c, 11 comprising a step provided on the guide member 11.
It bends at the position of d.

On the downstream side of the guide member 11, there is provided a light emitting portion and a light receiving portion, and a photo sensor (sheet material detecting means) for detecting the front end and the rear end of the sheet material with or without reflected light.
PH, a conveying roller (transporting means) 13 for conveying the sheet material fed at a constant speed guided by the upper guide 28a and the guide member 11 fixed to the shaft 12 by the feeding roller 9, and rotated by the shaft 14. The sheet material is provided freely by the force of a spring 15 via a shaft
A first pinch roller 16 pressing the ink absorbing member 17
, A paper discharge roller 20 fixed to a shaft 19 for discharging a printed sheet material, and a rotatable shaft 21 for discharging the sheet by the force of a spring 22 via the shaft 21. 2nd pinch roller 2 pressing against
3, a carriage 26 which is guided by guide shafts 24 and 25 and is movable in the width direction of the paper, and is mounted on the carriage 26, and prints by discharging ink from a discharge unit 27a in accordance with image information. And a recording head 27 for performing the recording.

The carriage 26 includes a motor 29 provided on a central side plate 28 having an upper guide 28a, a pulley 30 provided on an output shaft thereof, and a belt fixed at one end to the carriage 26 and attached to the pulley 30. 3
1 driven.

Further, inside the case 1, an operation electric board 33 provided with a plurality of switch buttons 32 provided protruding from holes of the case 1, and a microcomputer provided below the sheet material mounting table 4. A control electric board (control means) 34 for controlling the operation of the apparatus by mounting a memory and a memory is appropriately arranged.

The mechanism of the present apparatus will be further described with reference to FIG. First, switching means for bringing the sheet material on the sheet material loading table 4 into contact with and separating from the feeding roller 9 will be described.

A driving cam (cam member) 7 fixed to the shaft 8 of the feeding roller 9 and a follower portion 4b provided on the sheet material mounting table 4 abut at a predetermined position by the force of the spring 5. The driving cam 7 is synchronized with the feeding rotation of the feeding roller 9.
With the rotation of the driving cam 7, the sheet loading table 4 moves up and down to contact and separate the sheet and the feeding roller 9.

A pulley 37 provided at one end of the transport roller shaft 12 and a pulley 3 provided at one end of the discharge roller shaft 19
8 is connected by a belt 39, the rotation of a motor M, which is a drive source, is transmitted to the paper discharge roller 20 via the shaft 12.

A cap table 41 having a cap 40 for covering the ink ejection portion 27a of the recording head 27 is provided on the opposite side of the sheet material conveyance path from the motor. The cap table 41 has a rotating shaft 41a and a push-down cam portion 41b.
The rotation is urged in the counterclockwise direction about. And
When the protrusion 26a of the carriage 26 comes into contact with the push-down cam 41b due to the movement of the carriage 26, the cap table 41 is pushed down against the force of the spring 42 and the cap 40 is also lowered, and the protrusion 26a is pushed down by the push-down cam 41.
b, the cap 40 rises, and the ejection portion 27
a to cover the discharge port.

The pump 43 has a piston shaft 43b having a rack 43a, a suction port 43c, and a discharge port 43d. The suction port 43c and the cap 40 are formed by a tube 40a. And the tube 44 are connected to each other, and the ink sucked from the cap 40 is discharged to the absorbing member 17 in the platen 18.

The pump driving gear 45 meshed with the rack 43a of the pump 43 is provided on the shaft 12 so as to be movable in the direction along the axis of the shaft 12 and to be interlocked with the rotation of the shaft 12. It is biased by a spring 46 to a position where it does not mesh with the rack 43a.

In the vicinity of the ejection port of the recording head 27, solid components of the ink are liable to adhere to the ejection port, which may cause ejection failure. At that time, the motor 29 moves the carriage 26 and connects the ejection unit 27 a to the cap 40 in accordance with a command from the controller 34 to perform the ejection failure recovery operation. The carriage 2
6, the protrusion 26b of the carriage 26 moves the pump drive gear 45 to the position shown by the two-dot chain line, so that the pump drive gear 45 is engaged with the rack 43a. In this state, when the gear 45 repeats a predetermined number of forward and reverse rotations within a predetermined rotation angle by the driving of the motor M, the rack 43a performs a reciprocating movement in the straight traveling direction a predetermined number of times. Since the reciprocating motion of the rack 43a also reciprocates the piston in conjunction with the piston shaft 43b, the pump 43 absorbs the ink and its solid content from the ink discharge portion 27a,
Further, the sucked material is discharged to the absorbing member 17 in the platen 18.

Next, the structure of the drive transmitting means for transmitting the rotation of the motor M to the discharge roller 9 and the transport roller 13 will be described.

The motor M has an output gear 47 provided on the motor shaft in response to a signal from the controller 34, and a two-stage gear 48.
Then, the conveying roller pairs 13 and 16 are rotated via the conveying roller gear 49 fixed to the shaft 12 to convey the sheet material.

On the other hand, the motor M rotates the output gear 47, the two-stage gear 48, and the gear 51 fixed to the shaft 50. A first planetary gear 53 meshing with a first sun gear 52 similarly fixed to the shaft 50 is constituted by a large planetary gear 53a and a small planetary gear 53b, and a shaft 54 of the first planetary gear 53 rotates around the shaft 50. It is pivotally supported by the moving first carrier 55.

The first planetary gear 53 is connected to one arm member 55 of the first carrier by a spring 56 provided on a shaft 54.
Since a predetermined pressure is applied to a, a certain load is applied to the rotation of the first planetary gear 53.

1 and 3, the first sun gear 52 rotates in the direction of the arrow 50a due to the rotation of the output gear 47 provided on the shaft of the motor M in the direction of the arrow 47a. Since a large load is applied to the rotation of the large planetary gear 53a that meshes with the first sun gear 52, the first planetary gear 53 revolves around the first sun gear 52 in the direction of the arrow 50a without rotating. The first carrier 55 also rotates in the direction of the arrow 50a by this revolution, so that the small planetary gear 53b and the gear 57 fixed to the feed roller shaft 8 are engaged with each other, so that the rotation of the motor M in the direction of the arrow 47a As a result, the paper feed roller 9 rotates in the feeding direction 8a.

The gear 57 is provided with a toothless portion 57a. When the rotation of the gear 57 advances and the toothless portion 57a comes into a meshing position with the small planetary gear 53b, the small planetary gear 53b idles and the gear 57 is rotated. The rotation of the gear 57 and the paper feed roller 9 in the feeding direction is stopped.

In FIG. 1 and FIG.
The sun gear 52 rotates in the direction of the arrow 50b due to the rotation in the direction 7b. Following the rotation, the first carriers 55, 55
a rotates together with the first planetary gear 53 in the direction of the arrow 50b. The rotation of the first carrier 55 in the direction of the arrow 50b causes the small planetary gear 53b to disengage from the meshing position with the gear 57,
The rotation of the first carrier 55 is stopped by the one arm member 55a of the carrier abutting on the pin 58. At the position where the rotation of the first carrier 55 is stopped, the small planetary gear 53b continues idling while the first sun gear 52 is rotating in the direction of the arrow 50b.

The gear 60 meshing with the first sun gear 52 and the second sun gear 61 are fixed to the shaft 59. A second planetary gear 62 that meshes with the second sun gear 61 is supported by a second carrier 63 that rotates freely around a shaft 59.
Since the second planetary gear 62 is pressed against one arm member 63a of the second carrier with a predetermined pressure by a spring 64, a constant load is applied to the rotation of the second planetary gear 62.

In FIG. 1 and FIG.
The gear 60, the shaft 59, and the second sun gear 6 are rotated by the rotation in the direction a.
1 rotates in the direction of arrow 59a, and in response to this rotation, the second carrier 63 moves together with the second planetary gear 62 in the direction of arrow 5a.
The second carrier 63 rotates in the direction 9a, and stops when the carrier arm member 63a finally comes into contact with the pin 65. When the second carrier 63 is stationary, the sun gear 61
The second planetary gear 62 continues idling by the subsequent rotation of.

In FIG. 1 and FIG.
By rotation in the direction 7b, the sun gear 61 rotates in the direction of the arrow 59b, and in response to this rotation, the second carrier 63
Similarly, the planetary gear 62 rotates in the direction of arrow 59b, and finally the second planetary gear 62 meshes with the toothless gear 57. Therefore, the rotation of the second sun gear 61 in the direction of arrow 59b is transmitted through the shaft 8 through the feed roller 9 To the feed direction 8a.

The rotation of the gear 57 by the driving of the second planetary gear 62 advances, and the toothless portion 57 a of the gear 57 is moved to the second planetary gear 62.
The second planetary gear 62 idles and cuts off the transmission to the gear 57.

At a predetermined angle α in a so-called non-interlocking process region in which the second planetary gear 62 does not mesh with the toothless gear 57 in the entire revolution angle region where the second planetary gear 62 revolves around the second sun gear 61. The second planetary gear meshes with the internal gear 66. Due to this meshing, the second planetary gear 62 revolves around the second sun gear 61 while rotating.

In FIG. 1, this non-interlocking process area is provided so that the gear 57 and the second planetary gear 62 do not mesh with each other when the pump 43 is operated by a predetermined amount of forward / reverse rotation of the motor M.

In this embodiment, when the motor M rotates by a predetermined amount necessary for performing the above operation, the angle as the non-interlocking process area is required to be 360 °, and the second planetary gear If 62 does not rotate but only revolves, 3
It is not possible to set a 60 ° uncoupled process area.

Therefore, the provision of the internal gear 66 allows the second planetary gear 61 to rotate on its own axis so as to reduce the revolution speed so that the non-interlocking process area can be set. This will be described. Assuming that the number of teeth of the second sun gear 61 is Z ₁ , the number of teeth of the second planetary gear 62 is Z ₂ , and the number of teeth of the internal gear 66 is Z ₃ , the relation is Z ₃ = Z ₁ + 2Z ₂ .

Therefore, the reduction ratio between Z ₁ and Z ₃ is Z ₁ / Z ₃ = 1/1 + 2 (Z ₂ / Z ₁ ). That is, when the second sun gear 61 rotates the angle region where the teeth of the internal gear 66 are provided by α degrees, the second planetary gear 62
Will perform a revolution of α / 1 + 2 (Z ₁ / Z ₂ ) degrees,
The revolution speed is greatly reduced.

For example, α = 120 °, Z ₁ = 10, Z ₂ = 1
If 0, the revolution angle β of the second planetary gear 62 is β = 120
° / 3 = 40 °.

On the other hand, in order for the second planetary gear 62 to revolve at 120 °, the second sun gear 61 needs to be 120 ° × 3 = 36.
This means that the rotation is performed at 0 °, so that the required uncoupled process area can be set at 120 °.

Next, a feeding operation and a print recording operation in the first embodiment will be described with reference to FIGS. 1 to 4 and FIGS. 5 to 8 are cross-sectional views showing main components for feeding the sheet material in FIG.

First, as an initializing operation, when the power of the apparatus is turned on, the motor M shown in FIG.
7a, that is, the conveying roller 13 moves the sheet material S in FIG.
3 and 5, the rotation of the motor M shown in FIGS. 3 and 5 is not transmitted to the feeding roller 9, and the sheet transmission unit Is in the state shown in FIG.

In FIG. 5, the stop surface lift surface 7b of the driving cam 7 and the follower portion 4 provided on the sheet material loading table 4 are shown.
In a state where b is engaged by the force of the spring 5, the sheet material mounting table 4 is stationary at a position where it has moved downward. In this state, a plurality of sheet materials S are placed on the sheet material mounting table 4 with their leading ends abutting below the contact member 10.

4 and 6, when the motor M is rotated by a predetermined amount in the direction of arrow 47b in response to a feed command from the controller 34, the second planetary gear 62 moves to the position where the second carrier 63 and the pin 65 abut. From the gear to the meshing position with the gear 57. The second planetary gear 6 that has come to this meshing position
2 transmits the rotation of the motor M in the direction of the arrow 47b to the gear 57, so that the feed roller 9 starts rotating in the direction of the arrow 8a, that is, in the feed direction through the shaft 8.

On the other hand, the first planetary gear 53 rotates around the first sun gear 52 in the direction of the arrow 50b by the rotation of the motor M in the direction of the arrow 47b, and moves away from the meshing position with the gear 57.

The rotation of the gear 57 causes the drive cam 7 fixed to the shaft 8 to rotate in the direction of the arrow 8a, so that the stop surface of the drive cam 7 at the stop surface 7b and the follower portion 4b provided on the sheet loading table 4 The engagement is released, and subsequently, the sheet material mounting table 4 is raised by the tensile force of the spring 5.

The uppermost sheet material S ₁ of the plurality of sheet materials S is moved by the raising of the sheet material mounting table 4 so that the rotating feeding roller 9 is rotated.
The uppermost sheet material S ₁ is in contact with the contact member 1
It is fed in the zero direction. The contact member 10 applied to the moving sheet material S changes its angle in the traveling direction of the sheet material due to the moving force of the sheet material S.

A case where the sheet material used has a particularly low surface friction coefficient and a further low elasticity will be described.

FIG. 7 shows that the feeding roller 9 further rotates in FIG. 6, the uppermost sheet material S ₁ further moves, and the leading end of the contacting member 10 and the leading end of the sheet material S ₁ coincide. Indicates that they are in a balanced state. The two feed rollers 9 on the left and right are made of chloroprene rubber, nitrile rubber, silicon rubber, or the like having a high coefficient of friction, and a plurality of sheet materials S loaded on the sheet material mounting table 4 are pressed by the force of the spring 5 with a pressing force F ₀ . It is pressed against the individual feeding rollers 9.

A friction coefficient of μ ₁ is provided between the feeding roller 9 and the sheet material S _1, and then a friction coefficient of μ ₂ is provided between the sheet material S ₁ and the second sheet material S _2. Furthermore, the friction coefficient between the sheet material S ₂ and the third sheet material S ₃ is μ ₃ , and the fourth and subsequent sheet materials also have a predetermined friction coefficient.

The friction coefficients μ ₁ and μ ₂ have a relation of μ ₁ ≫μ ₂ . Accordingly, when a plurality of sheet materials S stacked on the sheet material mounting table 4 are pressed against the surface of the feeding roller 9 by the force of the spring 5 with the pressing force of F ₀ , the uppermost sheet material S ₁
Is applied to the contact member 10 with a moving force F ₁ of F ₁ = F ₀ (μ ₁ −μ ₂ ). On the other hand, the moving force F ₂ of the second and subsequent sheet materials is F ₂ = F
Since (μ ₂ −μ ₃ ), μ ₂ ≒ μ _{3, the} value is smaller than F ₁ .

In FIG. 7, the uppermost sheet material S ₁ is F ₃
= F ₁ cos A ₁ consisting given change of A ₂ + A ₃ consisting angle of 10a in a position to contact member 10 per said with a force, the tip point 69 of the sheet S ₁ and the abutment member 10 at that time
In a state commensurate with the elastic force of each other in the movement of the sheet S ₁ considered to be stopped.

[0066] force of F ₃ press the pressure member 10 attaches the sheet S _{1, 4} the friction coefficient μ of the tip and abutment member 10 of the sheet S _1, the tangent 70 at the point 69 of the sheet S ₁ the with Assuming that the angle formed by the tangent line 71 at the point 69 of the contact member 10 is θ °, F ₄ = F ₃ cos θ ° F ₅ = F ₃ sin θ ° (1) F ₆ = μ ₄ F ₃ sin θ ° Therefore, F ₄ -F _{6> 0 F 3 (1-} μ 4 tanθ °)> 0 θ °> tan -1 1 / μ 4 ... (2) comprising sheet material S ₁ at theta ° is sliding out the surface of the pressure member 10 month.

A perpendicular 73 from the feed direction 72 through the point 69
A ₁ r is the angle between the tangent 70 and the perpendicular 74 from the point 69.
When ad sheet S ₁ is ^{_{A 1 ≒ F8L 2 2 K 1}} ... (3) K 1 = 1/2 × E 1 × I 1 ... (3) ' However K ₁ = elasticity of A ₁ of the sheet S ₁ = that flexed in the deflection angle (rad) _{L 2} = become the second moment of the flexure length E ₁ = Young sheet S ₁ ratio I ₁ = sheet S ₁ sheet S ₁ angle of the sheet S _{1 becomes, F 5 '= F 5 =} F 8 cosA 1 ° ( where _{a 1 ° = a 1 × 180} ° / π) ... a (4) by the balance.

The angle formed by the perpendicular 73 and the tangent 71 is A ₂ r
elasticity of the contact member 10 attached to the _{ad A 2 ≒ F 7 L 3} 2 K 2 ... (5) K 2 = 1/2 × E 2 × I 2 × n ... (5a) provided that K ₂ = abutment member 10 Degree A ₂ = deflection angle (rad) of contact member 10 L ₃ = deflection length of contact member 10 (with reference to fulcrum 11c) E ₂ = Young's modulus of contact member 10 I ₂ = contact member 10 N = the number of contact members 10 (in this embodiment, n =
By being flexed in 2) becomes angles, and F ₅ = F ₇ cosA ₂ ° by the balance (except _{A 2 ° = A 2 × 180} ° / π) ... (6).

On the other hand, the angle formed between the perpendicular 75 and the line segment 75 orthogonal to the point 69 and the tangent 70 is A ₁ °, and the angle formed between the line 75 and the line 76 orthogonal to the tangent 71 is A ₂ °
From the above relationship, θ ° + A ₁ ° + A ₂ ° ≒ 90 ° (= π / 2 rad) (7)

From equations (1), (4) and (6), F ₃ in a balanced state is F ₃ sin θ ° = F ₈ cos A ₁ ° = F
_{From the} relationship of ₇ cosA ₂ °, F ₃ = F ₈ cosA ₁ ° / sin θ ° = F ₇ cosA ₂ ° / sin θ ° (8) Therefore, the moving force larger than F ₃ obtained from the above equation (6) is obtained. sheet S ₁ when applied to the sheet material S ₁ of the tip abutment sheet S ₂ exits from the distal end of the second or subsequent member 10 by 9, S _3, is completely separated from .... This separating action is called a second separating action.

Assuming that θ ° is a value determined only from the friction coefficient μ ₄ from equation (2), from equation (5), A ₁ ° + A ₂ ° ≒ 90 ° -θ ° = constant (9)

The value of the elasticity K ₁ of the sheet material S ₁ constituting the equation (3) varies greatly depending on the type of the sheet material S. For example, if the elasticity of thin paper having a thickness of 0.065 mm is K ₁ -a and the elasticity of a postcard or an envelope is K ₁ -b, K ₁ -b / K ₁ -a ≒ 13 (10).

In the equation (9), θ ° at which the second separation is performed is A ₁ ° ≫A ₂ ° for thin paper. That is, the separation angle of the sheet material itself greatly contributes to separation of thin paper.

On the other hand, thick paper such as a postcard satisfies A ₁ ° ≧ A ₂ °. That is, the deflection angle of the contact member 10 greatly contributes to separation. When performing the separating operation, it is necessary to reduce the value of A ₂ ° in equation (9) as much as possible in order to prevent double feed of the second and subsequent sheets. A ₁ ° in equation (3)
The above (10) effects the value of the deflection length L ₂ of the thing vary greatly depending on the value of K ₁ but on the other hand the sheet S varies with the square for the deflection angle A ₁ by its suitability set (10) of such hits the formula Can be reduced.

[0075] As you increase the L ₂ thick paper is an advantage of being larger deflection angle A ₁ thin paper double-feed tends also deflection second and subsequent sheets of paper occurs. Deflection angle A ₂ of the abutment member 10 for L ₂ a small and it is advantageous is going and thin paper has a small deflection angle A ₁ and is less likely to thick paper deflection
Becomes large and double feed occurs on the second and subsequent sheets. From the above results, good separation was possible by setting the elasticity K ₁ of the sheet material S within the range shown by the expression (10) by setting L ₂ to be 15 to 25 mm.

Next, the case of a sheet material having a high surface friction coefficient μ and a particularly high elasticity among the sheet materials to be used will be described.

[0077] In FIG. 8, the feed roller 9 and has a friction coefficient mu ₁₁ between the sheet material S _1, then the sheet material S ₁ and ₂ mu between the second sheet material S ₂ has a coefficient of friction, mu ₃ further between the sheet material S ₂ and third sheet material S ₃
The fourth and subsequent sheet materials also have a predetermined coefficient of friction.

The friction coefficients μ ₁₁ and μ ₂ have a relationship of μ ₁₁ ≫μ ₂ . Accordingly, when a plurality of sheet materials S stacked on the sheet material mounting table 4 are pressed against the surface of the feed roller 9 by the force of the spring 5 with the pressing force of F ₀ , the uppermost sheet material S ₁ becomes F ₁₁ = F ₀ (μ ₁₁ −μ ₂ ) The contact member 10 is hit with a moving force F ₁₁ . On the other hand, the moving force F ₂ of the second and subsequent sheet materials is F ₂ = F
Since (μ ₂ −μ ₃ ), μ ₂ ≒ μ _{3, the} value is smaller than F ₁ .

In FIG. 8, the uppermost sheet material S ₁ is F ₃
= F ₁₁ cos A ₁₁
Is changed from the position 10a by an angle of A ₉ + A ₁₀ + A ₁₂ , at which point the sheet material S ₁ and the tip of the contact member 10 are balanced at the point 69 by the elastic force of each other, and the sheet material S Think that the movement of ₁ has stopped.

Note that A ₉ is an angle until the sheet material comes into contact with the projecting fulcrum 11 d, and A ₁₀ is an angle changed after the contact. In the state where the elastic members are balanced with each other as described above, the guide member 11 is located near the root of the contact member 10.
Is in contact with the protrusion 11d provided on the deflection length L ₁₃ of the thus abutment member 10 at the resilient force of the abutting member 10 per shorter than the deflection length L ₃ in the first fulcrum 11c is has changed the support position From discontinuous to suddenly increase.

When the protruding portion 11d comes into contact with the contact member 10, the contact member 10 may come into contact with the contact member 10 entirely in the width direction or in an intermittent dot form.

In FIG. 8, the fulcrum 1 has no projecting fulcrum 11d.
1c only abutment elastic force F ₁₇ of the abutment member 10 if we have member 10 have bent 'is the (5) than _{F 17' ≒ (A 9 +} A 10) / L 3 2 K 2 = A 9 / ^{_{L 3 2 · K 2 + a}} 10 / L 3 2 K 2 ... (11) where K ₂ = abutment deflection angle of up to fulcrum 11d degree of elasticity a ₉ = abutment member 10 of the member ₁₀ (rad) a 10 = per would be bent the leading end of the sheet S ₁ by abutting the deflection angle from the fulcrum 11d of member 10 (rad) L ₃ = abutment elastic force deflection comprised length from the fulcrum 11c of the member 10.

[0083] On the other hand, deflected said abutment member as a fulcrum the fulcrum 11a in a protruding fulcrum 11d as shown in FIG. 8, the elastic force F ₁₇ of the contact member 10 attached is _{F 17 ≒ A 9 / L 3} 2 K ₂ + A ₁₀ / L ₁₃ ² K ₂ (12) where K ₂ = elasticity of contact member 10 A ₉ = deflection angle (rad) of contact member 10 to fulcrum 11d A ₁₀ = support point of contact member 10 to deflect distal portion of the sheet S by the deflection angle (rad) L ₃ = abutment deflection length becomes elastic force from the fulcrum 11d of the deflection length L ₁₃ = abutment member 10 from the fulcrum 11c of the member 10 from 11d Will be.

The difference between the elastic forces F ₁₇ and F ₁₇ ′ is given by the following equation (1).
From 1) and (12)

[0085]

[Outside 1] Here, L ₃ and L ₁₃ have the following relationship.

[0086] L _3> L ₁₃ ... (14) Equation (13), (14) from ^{_{L 3 2 -L 13 2 = (}} L 3 -L 13) (L 3 + L 13)> 0 Thus F ₁₇ -F _{17 '> 0 F 17> F 17} ' ... (15) by providing the next supporting point 11d (15) even sheet S ₁ larger elastic force becomes possible to increase the elastic force of the street with the pressure member 10 shown in the expression It is possible to separate each sheet.

[0087] Here, the elastic force of the deflection length L ₂₃ abut against to further shorten the member 10 of the abutment member 10 by further providing the projected fulcrum 11e becomes larger, further each one in a large sheet of resilient force Can be separated.

Further, the position of the projecting fulcrum 11e is provided further upward, and the vicinity of the tip end of the contact member 10 is moved to the fulcrum 11e.
By making contact, the fulcrum 11e can also function as a stopper that limits the deflection angle of the contact member 10 to a constant value.

Next, the correction of the skew of the sheet material fed and separated will be described.

In FIG. 9, when the leading end of the separated sheet material crosses the photo sensor PH, the photo sensor PH generates a signal, and based on this signal, the controller M in FIG. 2 causes the motor M to move the distance L ₅ + α (α). = Margin = 2
５5 mm), and then stop once after rotating for the number of pulses P ₄ equivalent to the number of pulses. The leading end of the sheet material S ₁ by the feed roller 9 which operates in response to the rotation of the speed of the pulse motor P _4, arrow 49b
Roller 13 and first pinch roller 16 rotating in the reverse direction
Devoted per contact position 77, the tip movement of the sheet S ₁ is prevented.

If the feeding roller 9 is still rotating while the movement of the sheet material S ₁ is stopped, the feeding roller 9 rotates while slipping on the upper surface of the sheet material S ₁ .

When the sheet material S ₁ is skewed, one of the leading ends first comes into contact with the contact position 77, and the movement of one of the leading ends is stopped. Rotate around one end. The leading end of the sheet material S ₁ by the rotation skew is corrected by aligned parallel to the contact position over its entire width.

[0093] After rotation of the pulse number of the motor of the P _4, the motor M from the distance L ₆ equivalent performs forward rotation in the arrow 47a direction number of pulses P ₅ (FIG. 4 conveyed by the conveying rollers 13 FIG. 3). Roller 9 feeds the rotation number of pulses P ₅ of the motor M is performed further rotation pushing the leading edge of the sheet S ₁ to the contact position 77, the leading end of the sheet S ₁ which is pushed in the arrow of the conveying roller 13 49b is conveyed by the rotation of the reverse direction until the distance L ₆ is a.

Next, will be described conveyance of the sheet material after correcting skew of the sheet S _1.

The controller 34 causes the output gear 47 of the motor M in FIG. 1 to rotate in the direction of the arrow 47a according to the total number of drive pulses _{PT of the} motor M and the passing signal of the sheet S generated by the photosensor PH.

In FIG. 10, the conveyance roller 13 is rotated in the direction of arrow 49a by the rotation of the gear 47. On the other hand, at the same time, the carrier 55 rotates about the shaft 50 in the direction of the arrow 50a, so that the small planet gear 53b of the first planet gear 53 and the gear 57 are instantaneously engaged. The feeding roller 9 by engagement pushes the leading end of the sheet S ₁ by rotating the feeding direction to the contact position 77 of the conveying roller 13 and the first pinch roller 16. The leading end of the pushed sheet material S ₁ passes through the contact position 77 by the rotation of the transport roller 13.

[0097] Since the roller 9 feeding during fed until the sheet S ₁ is passed through the contact position 77 is rotated while holding the upper surface of the sheet S, as described in FIG. 7, the second sheet following the sheet material S _2, S _3, sufficiently small moving force F ₂ acts from F ₁ to ..., angular change in abutment member 10 is performed by the moving force F ₂ is in that abuts against the abutting member 10 attaches the sheet S ₂ Since θ ° constituting the equation (2) is θ ° ≧ tan ⁻¹ 1 / μ ₄ (16), the front ends of the second and lower sheet materials S ₂ , S ₃ ,. Therefore, the leading end of the sheet material does not exceed the leading end of the contact member.

On the shaft 8, the gear 57, the driving cam 7, and the feeding roller 9 are integrated with each other in a state where the relative phase relationship is maintained constant in each direction. The drive cam 7 has a drive lift surface 7a, a maximum lift surface 7b, a stop position lift surface 7d having a smaller lift amount than the maximum lift surface 7b, and an inclined surface 7c connecting the maximum lift surface 7b and the stop position lift surface 7d. have.

The rotation of the small planetary gear 53b of the first planetary gear 53 causes the driving cam 7 to move through the gear 57 and the shaft 8 by the arrow 8a.
Rotate in the direction. During this rotation, the drive lift surface 7a and the follower portions 46 provided at the left and right ends of the sheet material loading table 4 abut against each other, and the rotation of the driving cam 7 causes the sheet material loading table 4 to rotate about the shaft 4a. Rotate downward against force.

By the downward rotation of the sheet loading table 4, the upper portion of the sheet S is released from the state of being pressed by the feed roller 9 by the force of the spring 5 and is released from any pressing force. Therefore, the second and subsequent sheet materials S ₂ , S ₃ ,...
Of the second and subsequent sheets S ₂ , S ₃ ... Due to the restoring force of the abutment member 10.
While moving in the reverse feeding direction, the sheet moves downward following the downward rotation of the sheet material stacking table 4.

Since the second and subsequent sheet members S ₂ , S _3, ... Move away from the surface of the contact member 10 on which the sheet material contacts, the change in the angle of the contact member 10 is the first angle change. Return to the state without. In this way, the load related to the contact member 10 is released.

In the state shown in FIG. 11 where the force for pressing the upper surface of the sheet material S is released,
Sheet S ₁ is being restricted from sagging downward from a predetermined position by 1b. That is, the regulated sheet material S
_A predetermined gap 7 between the lower surface of
The positions of the apex 11b and the tip of the contacting member 10 are appropriately set so as to make 8.

[0103] By providing the gap 78, the tip of the abutment member 10 in the process of abutment member 10 returns to the absence of the first angle change is without interference from the sheet material S _1, thus returning operation reliably Can be done. Also by providing the gap 78, to generate abnormal noise interferes with the pressure member 10 per during movement of the sheet material S ₁ the uppermost is prevented.

In the feeding roller 9 having a long radius portion and a short radius portion as a sheet material feeding means, the sheet roller rotates while being in contact with the sheet material by a high friction surface such as rubber on the surface of the long radius portion. After the sheet material is sent out, the short radius portion is made to face the upper surface of the sheet material. Since the short radius portion has a flange portion 9a made of a low friction material protruding and the high friction surface is buried, the sheet material is sent out, the transport roller 13 starts transporting, and the short radius portion faces the upper surface of the sheet material. The amount of deflection of the sheet material is reduced by the difference between the lengths of the long and short radius portions, and at the same time, part of the flange portion 9a contacts the upper surface of the sheet material being conveyed to prevent the sheet material from rising. Guide the transport while At this time,
Since the flange portion 9a is formed from a low friction material,
The resistance at the time of conveying the sheet material decreases, and the fluctuation of the load applied to the motor M, which is the driving source of the conveying roller 13, also decreases, so that the accuracy of conveying the sheet material by the conveying roller 13 improves.

11 and 12, the maximum lift surface 7b of the drive cam 7 passes through the contact portion 46a of the follower portion 4b, and at the same time, the toothless portion 57a of the gear 57 is connected to the small planet gear 53b of the first planet gear 53. Come to the meshing position of
The rotation transmission to the gear 57 by the small planetary gear 53b is cut off, and the rotation of the gear 57 and the feed roller 9 stops.

[0106] min to the inclined surface 7c the rotation of the first planetary gear 57b of the gear 57 is abutting portion 46a of the stop after follower portion 4b presses the inclined surface 7c of the drive cam 7 by a force F ₁ 1 spring 5 The force F ₁₂ acts to drive the cam 7 and the gear 5
7 rotates a small amount in the direction of arrow 8a, and when the contact portion 46a slides on the inclined surface 7c and reaches the position of the stop position lift surface 7d of the drive cam 7, the rotation of the drive cam 7 stops.

The lift surface 7d of the drive cam 7 and the abutment portion 46a of the follower portion 4b are formed in an arc shape having substantially the same radius, and stop when they are fitted. At this time, the force (spring 5) applied to the drive cam 7 from the follower portion 4b
Is the direction toward the axis of the shaft 8 (arrow in FIG. 12).
, And is reliably stopped by friction between the lift surface 7d and the contact portion 46a.

In FIG. 12, when the contact portion 46a is at the stop position lift surface 7d, the phase of the toothless portion 57d of the gear 57 becomes the small planetary gear 53b and the toothless portion 57 of the first planetary gear 53.
a is slightly advanced from the position where the meshing was interrupted. In this way, by advancing the phase of the toothless gear by a predetermined amount, the teeth near the toothless portion of the gear 57 are completely retracted from the position where they mesh with the teeth of the small planetary gear 53b. The interference between the teeth is completely eliminated, so that the problem of vibration and abnormal noise caused by the interference between the teeth can be eliminated. The drive cam 7 and the follower portion 4b
May be reversed. That is, the drive cam 7 side may have a convex shape, and the follower portion 4b may have a concave shape.

In FIG. 12, when the motor M rotates by the number of pulses P ₄ corresponding to the distance L ₆ , the leading end of the sheet material S ₁ moves from the contact position 77 to a position advanced by L _6.
3 transported. The length L ₆ is set to the controller 3 so that the printing position of the head nozzle of the ink ejection section 27 a of the recording head 27 is a predetermined length L ₇ from the leading end of the sheet material S _1.
4 is set.

[0110] The user may, for example 1.5 mm, it is possible to instruct the printer controller 34 through the computer the values of L ₇ of Toka 3mm and is connected to the recording apparatus.

Here, while the feeding roller 9 and the conveying roller 13 convey the leading end of the sheet material S ₁ to the position L ₆ , the contact portion 46 a of the follower portion 46 must be at the stop position lift surface of the driving cam 7. It must be in contact at position 7a. Figure If when uncertainty abutment of the abutment portion 46a and the lift surface 7a by reducing the length L ₇ comes in 12, first the length L was set L ₇ sufficiently large value ₆ is carried out, and then the conveying roller 13 is rotated in the reverse direction to carry out reverse feeding of a predetermined length L ₁₃ (L ₆ > L ₁₃ ). ₁₄ forwards.

[0112] The above mentioned way the operation and the lift surface 7a becomes possible to change the print position length L ₁₄ arbitrarily keep iterator constant length L ₆ of the contact portion 46a of the follower portion 46 The contact is ensured.

[0113] Positive feed by performing the length L ₁₄ after reverse feeding was performed in Matanaga of L _13, conveying the rotation of the motor M roller 1
Backlash gear means for transmitting the 3 are those capable of very small 0, conveyance accuracy variation of the transfer for the recording carried out after conveying of the conveying roller 13 the length L _14.

1 and 12, the recording head 27
Controller 34 while the top of the printing position until the fed sheet S ₁ reciprocates the carriage 27 in the main scanning direction
Indicated by recording the predetermined image by ejecting ink from a discharge portion 27a of the recording head 27 onto the sheet S ₁ of the.
When recording of one line is completed, the controller 34 controls the motor M to feed the sheet material S one line in the sub-scanning direction.

Recording head 27 by [0115] It repeating the above operation is carried out the characters and images recorded over the entire surface of the sheet material S _1.

[0116] the sheet S ₁ when the sheet material S ₁ is to move in the sub-scanning direction by the conveying roller 13 is a major arc shape is regulated by the vertex 11b of the flange portion 9a and the guide member 11 of the feed roller 9 moving while rearward load during the rotation of the conveying roller 13 does not act only low contact resistance between the guide member 11 and the sheet material S ₁ is very small.
If this rearward load is extremely small, the fluctuation of the load applied to the motor M is also small, so that the conveyance accuracy of the conveyance roller 9 is improved, and as a result, the recording accuracy by the recording head 27 is also improved and the image quality is improved.

In FIG. 1, FIG. 2 and FIG.
_When the rear end of ₁ is detected by the photo sensor PH, the controller 34 predicts the length L ₈ from the detection position of the photo sensor PH to the rear end nozzle position of the ink ejection unit 27a, and records within the length L _8. made to perform a continuous rotation of a predetermined amount of conveying roller 13 and the discharge roller 20 after performing the recording by the head 27 to discharge the sheet S ₁ through the discharge opening 1b in FIG.

After continuous rotation of the discharge roller 20 by a predetermined amount, the controller 34 performs the feeding operation of the next sheet material S according to an instruction from a computer connected to the recording apparatus.

Further, according to the present invention, the recording head in the above embodiment is replaced with a reading head, and the image information of the sheet document fed from the feeding device by the movement of the carriage 26 in the main scanning direction is read. The present invention can also be applied to an information processing device for inputting the information to a computer.

[0120]

As described in detail above, the use of the technique of the present invention makes it difficult to separate sheets one by one in the prior art, and in particular, a sheet material having a low surface friction coefficient μ and particularly a rigidity. Sheet material can be fed by one separating means and separated one by one, so that the range of types of sheet materials using the sheet material feeding device can be greatly expanded.

[Brief description of the drawings]

FIG. 1 is a perspective view illustrating a configuration of a recording apparatus including a sheet material feeding device according to the present invention.

FIG. 2 is a longitudinal sectional view of the recording apparatus shown in FIG.

FIG. 3 is a diagram showing a forward rotation state in the drive transmission mechanism of the sheet material feeding device of the present invention.

FIG. 4 is a diagram showing a reverse rotation state in the drive transmission mechanism of the sheet feeding apparatus of the present invention.

FIG. 5 is a side view showing a state before separation of the sheet feeding apparatus of the present invention.

FIG. 6 is a side view showing a state in which the sheet feeding apparatus of the present invention is being separated;

FIG. 7 is a side view showing a force relationship during separation of the sheet material feeding device of the present invention.

FIG. 8 is a side view showing a force relationship during separation of the sheet material feeding device of the present invention.

FIG. 9 is a side view showing a sheet material feeding amount of the sheet material feeding device of the present invention.

FIG. 10 is a side view showing a state in which the drive transmission mechanism of the sheet feeding device according to the present invention has switched from a reverse rotation state to a normal rotation state.

FIG. 11 is a side view showing a state in which a sheet feeding member is separated from a feeding roller in the sheet feeding device of the present invention.

FIG. 12 is a side view showing a state in which the toothless portion of the gear is positioned after the feed roller and the sheet material are separated from each other in the sheet material feeding apparatus of the present invention.

FIG. 13 is a diagram showing an example of the prior art of the present invention.

FIG. 14 is a diagram showing an example of the prior art of the present invention.

FIG. 15 is a diagram showing an example of the prior art of the present invention.

[Explanation of symbols]

 4 sheet material loading table (sheet material loading means) 9 feed roller (sheet material feeding means) 10 contact member (plate member) 11c, 11d, 11e fulcrum

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B65H 3/56 B41J 13/00 B65H 3/46 G03G 15/00

Claims (8)

(57) [Claims] 1. A sheet material stacking means for stacking a plurality of sheet materials, a sheet material feeding means for feeding a sheet material stacked on the sheet material loading means, and a sheet fed by the sheet material feeding means. Separation means having a plate-like member for separating the sheet material one by one as the sheet material climbs over elastically due to the contact of the sheet material, and the sheet material gets over, A sheet feeding device, comprising: fulcrum changing means for changing a fulcrum of the plate-shaped member in a direction in which the member is deformed. 2. The fulcrum changing means includes: a first fulcrum imparting portion that contacts at least the plate-shaped member first after the plate-shaped member is curved and deformed; 2. The sheet feeding device according to claim 1, further comprising: a fulcrum providing unit. 3. The sheet material feeding device according to claim 1, wherein the first and second fulcrum imparting portions are formed of step portions arranged in front and rear directions of the sheet material in the feeding direction. 4. The sheet-shaped member is mounted so as to be inclined such that an end on a side where the sheet material goes over a plane perpendicular to a feeding direction of the sheet material is on a side of the sheet material stacking means. The sheet material feeding device according to claim 1, wherein 5. The sheet feeding device according to claim 4, wherein the plate member is formed of a synthetic resin film. 6. A sheet feeding apparatus according to claim 1, further comprising: a recording unit configured to record on a sheet fed by the sheet feeding apparatus. Recording device. 7. An ink-jet recording means for applying a current to an electrothermal transducer in response to a signal and ejecting ink by growth of bubbles generated by heating exceeding film boiling by the electrothermal transducer to perform recording. The recording apparatus according to claim 6, wherein: 8. A sheet material separating method for separating a sheet from a stacked sheet portion on which the sheet is stacked by using a plate-like elastic member having a free end, wherein the relatively thin sheet material is a first fulcrum applying portion. The sheet material is separated by the plate-like elastic member which is curved with the fulcrum as a fulcrum, and the relatively thick sheet material is curved with the second fulcrum imparting portion disposed at a free end side of the first fulcrum imparting portion as a fulcrum. A sheet material separating method, wherein the sheet material is separated by a plate-like elastic member.