JPH0558525A - Sheet carrying device - Google Patents

Abstract

PURPOSE:To enable simplification of the constitution by providing a sheet feeding means, a guide means, a pressing member, a pressure releasing means to release the pushing pressure, and a control means to control the sheet feeding means in an interlocking manner with the pressure release of the pressure releasing means. CONSTITUTION:When a paper sheet feeding signal is received by a control circuit, or the control circuit generates the paper sheets feeding signal in itself, motors for carrying and paper sheets feeding are driven, and a carrying roller 4a and a discharging roller 4c are rotated counterclockwise. A solenoid 51 is excited and a plunger 51a is sucked. Then, an arm 53 is protruded and rotated around a shaft 52, and sheet suppressing members 7a, 7b are rotated in a swaying manner in the direction where tight contact of the sheet suppressing members with a platen 5 is lost. At the same time, engagement of a paper sheet feeding clutch control claw 54a with a protruded arm end part 53d is separated, and the recorded sheet is carried out due to the rotation of the paper sheet feeding roller, toward the carrying roller 4a and the discharging roller 4c.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet conveying device having a sheet pressing means for preventing floating of a recording sheet.

[0002]

2. Description of the Related Art Conventionally, in a recording apparatus for serial recording, one line of recording is performed by scanning a carriage, and then a required amount of a recording sheet is conveyed to perform recording of the next and subsequent lines. Examples of such a recording device include an ink jet printer and an impact printer. In these recording devices, it is attempted to improve the recording quality by making the distance between the recording sheet and the recording head as close as possible.

However, if the recording sheet floats or sags at the recording position, the recording sheet and the recording head may rub against each other and the sheet may become dirty.

Therefore, as shown in FIG. 16, the sheet pressing members 7a and 7b are lifted by pressing the recording sheet 5 in the passage area of the recording head 6 through the roller-shaped pressing members 9a and 9b by the weight of the carriage 52. Was prevented. Reference numeral 5 is a platen plate, 4a, 4b, 4c and 4d are conveying rollers. The sheet pressing member 7a is swingably engaged with the rotation axis of the transport roller 4b as a center, and the sheet pressing member 7b is swingably engaged with the rotation axis of the transport roller 4d as a center.

The sheet pressing member 7a is urged by the leaf spring 14 to prevent the sheet from being disturbed except when the carriage is scanning.
Is rotated by the biasing force of the torsion spring 16 and retracted.

[0006]

However, in the above structure, when a sheet pressing member having a low rigidity, such as a thin plate, is used, the pressing member 14 is always biased against the sheet pressing member 7a. As shown in FIG. 10, the sheet pressing member 7a is deformed by the pressing force P of the plate spring 14 during the scanning of the carriage, and the end portion 7c of the sheet pressing member comes into contact with the recording heads 6a, 6b, 6c, 6d to damage the head. There was a risk of being lost. In particular, when a plurality of heads are mounted on the carriage as shown in FIG. 17, the carriage becomes long in the scanning direction, and contact due to deformation of the pressing member is likely to occur.

In order to solve this, it is conceivable to use a driving means for the sheet pressing member using a solenoid or the like and release the bias so that the sheet pressing member is not deformed during scanning of the carriage. There was an adverse effect that it became complicated and the cost became high.

[0008]

The structure of the present invention for solving the above-mentioned problems includes a feeding means for feeding a sheet, a guiding means for guiding the sheet fed by the feeding means, and a sheet for guiding the sheet. A sheet comprising: a pressing member to be pressed against the guiding means; a releasing means for releasing the pressing of the pressing member; and a control means for controlling the feeding means in conjunction with the pressing release operation of the releasing means. It is a carrier device.

[0009]

Next, a recording apparatus according to an embodiment of the present invention in which the above means is applied to an ink jet recording system will be described.

In this recording apparatus, as shown in FIG. 1, recording sheets 2 stacked in a cassette 1 are fed one by one by a pickup roller 3, which is conveyed by a sheet conveying means 4 and a backside of a platen. The recording head 6 serving as recording means is driven to perform recording on the recording sheet 2 supported by 5, and the sheet pressing member 7 is configured to suppress the floating of the recording sheet 2 during the recording. ..

The sheet pressing member 7 is configured to be pressed against the recording sheet 2 by a pressing roller 9 attached to the carriage 8 when the carriage 8 moves during recording.

Next, the configuration of each of the above parts will be specifically described.

(Sheet Conveying Means) The sheet conveying means 4 is a conveying roller 4a and a pinch roller 4b for conveying the recording sheet 2 to the recording area as shown in FIG. 1, and a discharging roller for discharging the recorded sheet 2 to a discharging tray 10. 4c and pinch roller 4d. The transport roller 4a and the discharge roller 4c are connected to a transport motor (not shown) and can be driven and rotated. The pinch rollers 4b and 4d are attached to one end of the arm 4f rotatable about the shaft 4e. The tension roller 4g attached to the other end of the arm 4f causes the transport roller 4a and the discharge roller 4c.
It is configured to be pressed against. As a result, when the carry motor is driven, the recording sheet 2 is carried in the direction of arrow a in FIG.

Incidentally, the driving force is transmitted so as to rotate at a rotational peripheral speed several% higher than the rotational peripheral speed of the discharge roller 4c and the conveying roller 4a, and an appropriate tension is applied to the conveyed recording sheet 2. It is configured as follows.

(Recording Means) The recording means records an ink image on the recording sheet conveyed by the conveying means. An inkjet recording system is used as a recording unit in this apparatus.

In the ink jet recording system, a liquid ejection port for ejecting and ejecting a recording ink liquid as flying droplets is provided in a liquid channel communicating with the ejection port, and a part of this liquid channel, and a flow is provided. Ejection energy generating means for giving ejection energy for causing the ink liquid in the passage to fly. Then, the ejection energy generating means is driven according to the drive signal to eject ink droplets to record an image.

As the discharge energy generating means, for example, a method of using pressure energy generating means such as an electromechanical transducer such as a piezo element is used, and electromagnetic waves such as a laser are radiated and absorbed by the ink liquid to generate heat, and the heat is generated. There are a method of using an electromagnetic energy generating means for ejecting ink, a method of using a thermal energy generating means for heating ink liquid by an electrothermal converter to eject ink, and the like. Among them, the method of ejecting ink by using a heat energy generating means such as an electrothermal converter allows high-resolution recording because liquid ejection ports can be arranged at high density, and the recording head is compact. It is suitable because it can be converted into

In this embodiment, as the recording means, the bubble jet recording method proposed by Canon Inc. is used among the ink jet recording methods.

FIG. 2 is an exploded view of the recording head 6 constituting the recording means, and FIGS. 3 to 9 are explanatory views of the bubble jet recording principle.

In FIG. 2, 6a is a heater board, which is an electrothermal converter (discharge heater) 6 on a silicon substrate.
b, an electrode 6c made of aluminum or the like for supplying electric power thereto is formed and disposed. A ceiling plate 6e having a partition wall for partitioning the liquid passage (nozzle) of the recording liquid is bonded to the heater board 6a. An ink cartridge for supplying ink to the recording head 6 is replaceably attached to a predetermined position of the apparatus.

The ink supplied from the ink cartridge through the conduit is supplied to the top plate 6e through the supply port 6f.
Then, the common liquid chamber 6g in the recording head 6 is filled, and is introduced into each nozzle 6d from the common liquid chamber 6g. Ink ejection openings 6h are formed in these nozzles 6d, and the ejection openings 6h face the recording sheet 2 and face downward at a predetermined pitch in the sheet conveying direction.

In this embodiment, the recording head 6 having the above-mentioned structure is mounted on a reciprocating carriage, and ink is ejected and ejected from the recording head 6 in synchronization with the movement of the carriage to perform recording.

The principle of ink ejection in the bubble jet recording system is described in, for example, US Pat. No. 472.
What is carried out by using the basic principle disclosed in the specification Nos. 3129 and 4740796 is preferable.
This method can be applied to both the so-called on-demand type and the continuous type. In particular, in the case of the on-demand type, nucleate boiling is performed in correspondence with the sheet or liquid path holding the liquid (ink). By applying at least one drive signal that provides a rapid temperature rise over, thermal energy is generated in the electrothermal transducer, causing film boiling on the heat-acting surface of the recording head, resulting in a pair of drive signals. This is effective because bubbles corresponding to one can be formed in the ink. Ink is ejected through the ejection openings by the growth and contraction of the bubbles to form at least one ink droplet. If this drive signal is made to have a pulse shape, the growth and contraction of bubbles are immediately and appropriately performed, so that it is possible to achieve the ejection of ink with excellent responsiveness.

This will be briefly described with reference to FIGS. 3 to 9. In the steady state, as shown in FIG. 3, the ink 11 filled in the nozzle 6d has the surface tension and the external pressure balanced at the ejection port surface. is doing. When flying the ink 11 in this state, the electrothermal converter 6b in the nozzle 6d is energized to cause the ink in the nozzle 6d to rapidly rise in temperature over nucleate boiling. Then, as shown in FIG. 4, the ink adjacent to the electrothermal converter 6b is heated to generate minute bubbles (bubbles), the ink in the heated portion is vaporized to cause film boiling, and as shown in FIG. The bubble 12 grows rapidly.

When the bubble 12 grows to the maximum as shown in FIG. 6, ink droplets are pushed out from the ejection port in the nozzle 6d. When the electricity supply to the electrothermal converter 6b is completed, the grown bubbles 12 are removed from the nozzle 6d as shown in FIG.
The ink 11 inside cools and contracts, and the growth and contraction of the bubbles cause ink droplets to fly from the ejection ports. Further, as shown in FIG. 8, the ink is brought into contact with the surface of the electrothermal converter 6b and is rapidly cooled, and the bubbles 12 are reduced or contracted to a substantially negligible volume. When the bubbles 12 contract, ink is supplied from the common liquid chamber 6g into the nozzle 6d by a capillary phenomenon as shown in FIG. 9 to prepare for the next energization.

Therefore, the ink image can be recorded on the recording sheet by reciprocating the carriage and energizing the electrothermal converter 6b in synchronization with this movement in response to the pulse-shaped drive signal. As the pulse-shaped drive signal, those described in US Pat. Nos. 4,463,359 and 4,345,262 are suitable. When the conditions described in US Pat. No. 4,313,124, which is an invention relating to the temperature rise rate of the heat acting surface, are adopted, more excellent recording can be performed.

In the recording system, it is preferable to provide recovery means, preliminary auxiliary means, etc. at the home position of the carriage. If these are specifically mentioned,
Capping means, cleaning means, pressurization or suction means, electrothermal converter 6b or a heating element other than this, preheating means by a combination thereof, or ejection different from recording is performed on the recording head 6. More stable recording can be performed by using a means for performing the preliminary ejection mode.

(Carriage) The carriage 8 is slidably and rotatably attached to the slide rail 8a shown in FIG. 1, and the carriage 8 and the drive transmission system (not shown) cause the carriage 8 to move the recording sheet 2 along the slide rail 8a. It is configured to be able to reciprocate in the width direction.

A home position sensor for detecting the home position is provided at the home position of the carriage 8. When the carriage 8 is at the home position, it is outside the area of the recording sheet 2 (see FIG. Position 1).

(Sheet pressing member) Sheet pressing member 7
Is for preventing the recording sheet 2 from floating during recording, and the upstream side sheet pressing member is located on the upstream side in the conveying direction of the recording sheet 2 with reference to the recording area of the recording sheet 2 to be recorded by the movement of the recording head 6. 7a is provided, and downstream sheet pressing members 7b are provided on the downstream side of the recording sheet 2 in the conveying direction.

The upstream side sheet pressing member 7a is shown in FIG.
As shown in FIG. 2, the arm portions 7a ₂ are formed by bending from both ends of the pressing portion 7a ₁ having a length equal to or larger than the width of the recording sheet 2,
The arm portion 7a ₂ is rotatably supported by the shaft 13 (see FIG. 10).

Here, as shown in FIG. 12, the pivotal support engaging portion 7e of the arm portion 7a ₂ has a round elongated hole 7e elongated in the vertical direction.
It is possible to move up and down by a small amount at the same time as turning.

Further, an inclined portion 7a ₃ is formed on one end portion in the longitudinal direction of the pressing portion 7a ₁ , and a pressing roller 9a, which will be described later, attached to the lower portion of the carriage 8 has a pressing portion 7a _1.
It is easy to get on.

On the other hand, similarly to the upstream side sheet pressing member 7a, the downstream side sheet pressing member 7b is formed by bending the arm portions 7b _{2 at} both ends of the pressing portion 7b ₁ having a length greater than the width of the recording sheet 2. The arm portion 7b ₂ and the shaft 15 are engaged with each other as shown in FIG.

That is, since the shaft 15 and the arm portion engaging hole 7c are in the shape of a round oblong hole, the arm portion 7 with respect to the shaft 15 is formed.
A small amount of b _c can be moved vertically.

An inclined portion 7b ₃ is formed at one end of the pressing portion 7b _{1 in} the longitudinal direction, and a pressing roller 9b, which will be described later, attached to the lower portion of the carriage 8 is pressed by the pressing portion 7b _1.
It is easy to get on.

(Pressing Roller) The pressing roller 9 presses the sheet pressing members 7a and 7b against the platen 5. In this embodiment, an upstream pressing roller 9a and a downstream pressing roller 9b are provided at the lower end of the carriage 8. It becomes. When the carriage 8 moves in the direction of arrow d in FIG. 2, the pressing rollers 9a and 9b move the roller 9a to the upstream side sheet pressing portion 7a.
₁ , the roller 9b rides on the downstream side sheet pressing portion 7b ₁ .

(Sheet pressing member driving means) 51 is a solenoid, and each of the projecting arms 5 rotates about a shaft 52.
No. 3 fitting hole 53a and solenoid 51 plunger 51a
The shaft 54 is fitted. The protrusion of the arm 53 is rotated by the suction of the solenoid 51, and the tip ends 53b, 53 of the arm 53 are rotated.
c hits the sheet pressing members 7a and 7b, and drives the sheet pressing members 7a and 7b to a position where they are not in contact with the sheet (FIG. 10). When the suction of the solenoid 51 is stopped, the sheet pressing members 7a and 7b oscillate by their own weight to a position where they come into close contact with the sheet (FIG. 11).

(Paper Feeding Unit) The paper feeding roller 3 separates and conveys the recording sheet 2 in the cassette 1 by rotation by a driving unit (not shown), and conveys it to the conveying roller pair 4a, 4b. Here, the rotation of the paper feed roller 3 is controlled by the paper feed clutch 54 on the paper feed roller shaft 60. A known spring clutch is used as the paper feed clutch 54. When the control pawl 54a on the paper feed clutch 54 projects and engages with the end 53d of the arm 53, the built-in clutch spring loosens and the drive transmission is cut off. Thus, the rotation of the sheet feeding roller 3 is stopped, and when the engagement is released, the drive is connected by the clutch spring, and the sheet feeding roller is rotated by the driving by the driving means (not shown).

FIG. 14 shows a control block diagram of the recording apparatus. Reference numeral 100 denotes a control circuit including a CPU, 101 denotes a conveyance motor that drives the conveyance roller 4a and the discharge roller 4c,
A paper feed motor 102 drives the paper feed roller 3.
A single motor may be used for both the feeding motor and the paper feeding motor. Reference numeral 60 denotes a sensor that detects the presence or absence of paper near the nip portion of the discharge roller 4.

In the above construction, when a paper feed signal is sent from the outside to the control circuit or when the control circuit itself issues a paper feed signal, the feeding motor 101 and the feeding motor 1
02 is driven, and the transport roller 4a and the discharge roller 4c rotate counterclockwise in FIG. At the same time, the solenoid 51 is excited, and as shown in FIG.
When the sheet is sucked, the projecting arms 53 rotate about the shafts 52, respectively, and the sheet pressing members 7a, 7b swing and rotate in the direction in which the sheet pressing members 7a, 7b come into close contact with the platen plate 5 due to the abutting of the tip ends 53b, 53c. To do. At the same time, the engagement between the paper feed clutch control claw 54a and the protruding arm end portion 53d is released at the same time, so that the recording sheet 2 is sent out by the rotation of the paper feed roller 3 by the driving means (not shown), and is conveyed to the transport roller 4a and the discharge roller 4c. Head to. Here, the sheet pressing member 7
Since a and 7b are held above the platen plate 5, the recording sheet is conveyed in a non-contact state with the sheet pressing members 7a and 7b. The suction of the recording sheet 2 is stopped after the leading edge 2a of the recording sheet 2 passes through the pressing regions a and b of the sheet pressing member, that is, after a lapse of a predetermined time after the solenoid 51 is turned on. Then, the arm 53 is rotated by its own weight to rotate counterclockwise. Then, the sheet pressing member 7a is rotated counterclockwise by its own weight and the sheet pressing member 7b is rotated clockwise, and is brought into close contact with the recording sheet 2 as shown in FIG.

At the same time, the arm end portion 53d moves to a position where it engages with the paper feed clutch control pawl 54a, but the control pawl 54
Since there is one point a, the paper feed roller 3 makes one rotation, and when the paper feed roller 3 returns to the initial position, the control claw 54a engages with the arm end portion 53d, and the rotation of the paper feed roller 3 stops. The conveyance motor 101 is stopped at the same time as the rotation of the paper feed roller 3 is stopped or after a short time. This timing is based on the transportation motor 1
It is determined by counting the elapsed time from the start of 01 rotation and detecting that a predetermined time has elapsed.

Further, as shown in FIG. 10, when the sheet pressing member 7b on the downstream side in the conveying direction of the recording sheet is swingably held upward, the upstream side in the conveying direction is held in a wide C-shape. Even if the leading edge of the sheet 2 is curled, it is guided by the lower surface of the sheet pressing member 7b and is stably guided to the warp roller 4c.

Then, the carriage 8 is driven by the driving means 103 in the direction perpendicular to the paper surface and the ink is ejected from the head 6 while scanning to perform the recording operation. At this time, as shown in FIG. 12, even if the heights of the platen plate 5 and the shaft 15 and the height of the shaft 13 are different from a predetermined height due to variations, a round oblong hole fitting hole of the pressing member 7b. 7c and the shaft 15 and the fitting hole 7e of the pressing member 7a, the sheet pressing members 7a, 7b and the recording sheet 2 are firmly attached to each other by the weight of the sheet pressing member. Guaranteed. Further, the sheet pressing members 7a and 7b are brought into close contact with the recording sheet 2 by their own weight and the pressing rollers 9a and 9b, but they are not subjected to the pressing force that causes other deformations, and therefore the sheet pressing members 7a and 7b and the recording head due to the deformations. There is no fear of contact with 6. When one print scan of the carriage is completed, the carriage returns to the home position, and then the transport motor 101 is driven for a predetermined time to perform the paper feed operation for the print width.

When the printing operation and the paper feeding operation are repeated a predetermined number of times and the printing of the entire area of the paper is completed, the paper is discharged onto the tray 10.

Next, a case where a manual sheet is inserted from the discharge port for recording will be described.

FIG. 13 shows the paper conveyance at the time of manual paper feeding in this case.

When the recording paper 2 is inserted into the paper discharge roller, the sensor 60 detects this, and when a detection signal is issued, the paper discharge roller 4c and the conveying roller 4a start reversing and the recording paper 2 is indicated by an arrow. In the B direction, feed it into the main body. Further, when the detection signal is issued, the solenoid 51 is excited, so that the sheet pressing members 7a and 7b are held at positions where they do not come into close contact with the recording sheet 2. At this time, the sheet pressing member 7a on the downstream side of the conveyance of the recording sheet is held in a C-shape with the upstream side of the conveyance widened, so that even if the leading end portion of the recording sheet 2 is curled, the sheet pressing member 7a is It is guided by the lower surface and guided to the nip between the pair of transport rollers 4a and 4b.

The paper is further placed and stopped before the trailing edge of the paper comes out of the holding area of the sheet pressing member 7b. This timing is also determined by the elapsed time after the rotation of the transport motor 101 is started.

During this time, since the solenoid 51 is attracted, the end portion 53d of the projecting arm 53 on the paper feed roller side is
It is separated from the control ring 54 of the paper feed clutch. There is no problem if the feeding motor 102 is controlled to be turned off. However, when the feeding motor is also used, the feeding roller 3 is driven in the direction opposite to the rotation direction at the time of feeding, but in the loosening direction of the clutch spring. Since it is rotating, the drive is not transmitted and the feed roller 3 does not rotate.

Next, the suction of the solenoid 51 is stopped, the projecting arm 53 rotates counterclockwise, and the sheet pressing member 7
a and 7b are in close contact with the recording sheet. In the future, the transport roller will rotate in the forward direction and start fixed-step feeding. The operation of printing while the carriage reciprocates for each step feed is the same as that described above, and a description thereof will be omitted.

Although the bubble jet recording method is used as the recording means in the above-described embodiment, the recording head has a combination of the above-mentioned discharge port, liquid passage, and electrothermal converter (straight liquid passage or right-angled liquid). U.S. Pat. No. 4,558,333 and U.S. Pat. No. 445960, which disclose a configuration in which a heat acting portion other than the flow passage) is arranged in a bending region.
The configuration using No. 0 specification can also be effectively used. In addition, JP-A-59-59 discloses a configuration in which a common slit is used as a discharge portion of the electrothermal converter for a plurality of electrothermal converters.
No. 123,670 and Japanese Patent Laid-Open No. Sho 59-59, which discloses a structure in which an opening for absorbing a pressure wave of thermal energy corresponds to a discharge portion.
The configuration based on Japanese Patent Laid-Open No. 138461 is also effective. That is, the bubble jet method enables efficient and reliable recording regardless of the form of the recording head.

The recording head is also of a replaceable chip type that is fixed to the apparatus main body, electrically connected to the apparatus main body, and capable of supplying ink from the apparatus main body, or integrally with the recording head itself. It is also effective to use a cartridge type one provided with an ink tank.

Regarding the type and number of recording heads to be mounted, for example, only one is provided corresponding to a single color ink, or a plurality of recording heads are provided corresponding to a plurality of inks having different recording colors and densities. It may be provided. That is, for example, the recording mode of the recording apparatus is not limited to the recording mode of only the mainstream color such as black, but may be constituted by integrally forming the recording heads or a combination of a plurality of the recording heads. It is also extremely effective for a device having at least one of full colors by color mixing.

Further, in the above description, the ink is explained as a liquid, but it is an ink that solidifies at room temperature or lower and softens or liquefies at room temperature, or in the ink jet system, the ink itself is 30 ° C. or higher and 70 ° C. or higher. In the following, it is common to adjust the temperature in a range to control the temperature of the ink so that the viscosity of the ink is in a stable ejection range. Therefore, the ink may be in a liquid state when a use recording signal is applied. In addition, it is possible to prevent the temperature rise due to thermal energy from being positively used as the energy for changing the state of the ink from a solid state to a liquid state, or to use ink that solidifies when left standing for the purpose of preventing ink evaporation. However, in any case, when heat ink is liquefied by application of heat energy according to a recording signal and liquid ink is ejected, or when the ink reaches a recording sheet, it begins to solidify. It is also applicable when using an ink that has the property of being liquefied for the first time by energy. In such a case, the ink is retained as a liquid or solid in the recesses or through holes of the porous sheet as described in JP-A-54-56847 or JP-A-60-71260, It may be configured to face the electrothermal converter. In bubble jet recording, the most effective method for each ink described above is to execute the film boiling method.

Further, although the bubble jet recording method is exemplified as the recording means in the above-mentioned embodiment, another recording method such as a wire dot recording method may be used.

Further, the conveying means for the recording sheet is not limited to the roller type as in the above-mentioned embodiment, and the conveying force may be applied to the recording sheet 2 by a rotating belt or the like.

The recording device may be used as an image output terminal of an upper processing device such as a computer, a copying device combined with a reader or the like, or a facsimile device having a transmission / reception function. ,
It can be applied to various things.

In the present embodiment, the sheet pressing member is
Although an example in which two positions are provided on the upstream side and the downstream side in the sheet conveying direction is shown, the structure may be provided on either the upstream side or the downstream side.

Further, the constitution example using the solenoid and the projecting arm as the driving means for swinging the sheet pressing member has been shown, but other driving means such as the driving by the cams 70 and 71 as shown in FIG. You may use.

Reference numeral 70 denotes an eccentric cam, which is rotated about a shaft 71 by a driving means (not shown) to abut against the end portion 7f of the sheet pressing member 7 and press the sheet pressing member 7a to the position shown by the broken line in the figure.

Reference numeral 72 denotes a link arm which rotates about a shaft 73 and is biased counterclockwise by a spring 74. One end 72a of the link arm is in contact with the eccentric cam 70, and the other end 72b is engaged with the control pawl 54a of the paper feed clutch 54. Due to the rotation of the eccentric cam, the link arm 72 rotates to the position shown by the broken line in the figure, the engagement with the control claw 54a is released, and the sheet feeding roller (not shown) rotates to perform the sheet feeding operation.

[0063]

As described above, according to the present invention, since the feeding means is controlled in association with the movement of the pressing means for pressing the sheet, the structure can be simplified.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a configuration of a recording head.

FIG. 3 is an explanatory diagram of a bubble jet recording principle.

FIG. 4 is an explanatory diagram of a bubble jet recording principle.

FIG. 5 is an explanatory diagram of a bubble jet recording principle.

FIG. 6 is an explanatory diagram of a bubble jet recording principle.

FIG. 7 is an explanatory diagram of a bubble jet recording principle.

FIG. 8 is an explanatory diagram of a bubble jet recording principle.

FIG. 9 is an explanatory diagram of a bubble jet recording principle.

FIG. 10 is an explanatory cross-sectional view of a state where the sheet pressing member is separated from the platen.

FIG. 11 is an explanatory view of a state where the recording sheet is pressed against the platen by a pressing member.

FIG. 12 is a detailed explanatory view of a sheet pressing member.

FIG. 13 is an explanatory view of a cross section during manual paper feeding.

FIG. 14 is a circuit block diagram.

FIG. 15 is a diagram showing another embodiment.

FIG. 16 is a diagram showing a conventional example.

FIG. 17 is a diagram showing a conventional example.

[Explanation of symbols]

1 cassette 2 recording sheet 3 pickup roller 4 sheet conveying means 4a conveying roller 4c discharging roller 4b, 4d pinch roller 4e shaft 4f arm 4g tension spring 5 platen 6 recording means 6a heater board 6b electrothermal converter 6c electrode 6d nozzle 6e top plate 6f Supply port 6g Common liquid chamber 6h Ink discharge port 7 Sheet pressing member 7a Upstream sheet pressing member 7a ₁ Pressing part 7a ₂ Arm part 7a ₃ Inclined part 7b Downstream sheet pressing member 7b ₁ Pressing part 7b ₂ Arm part 7b ₃ Inclined Part 7c, 7e Fitting hole 8 Carriage 8a Slide rail 9 Pressing member 9a Upstream pressing roller 9b Downstream pressing roller 10 Discharging tray 11 Ink 12 Bubbles 51, 52 Solenoid 55, 56 Projecting arm 59 Paper feeding clutch

Claims (7)

[Claims] 1. A feeding unit for feeding a sheet, a guiding unit for guiding the sheet fed out by the feeding unit, a pressing member for pressing the sheet against the guiding unit, and a release of the pressing member. A sheet conveying device comprising: a releasing unit; and a control unit that controls the feeding unit in association with a pressing release operation of the releasing unit. 2. The sheet conveying apparatus according to claim 1, wherein the pressing member presses the sheet by its own weight. 3. The sheet conveying apparatus according to claim 1, wherein the control means has a clutch. 4. The sheet conveying apparatus according to claim 3, wherein the clutch is intermittently operated by the movement of the releasing means. 5. The sheet placing device according to claim 4, wherein the clutch is a spring clutch having a control member that selectively engages with the releasing means in response to the movement of the releasing means. 6. The sheet conveying apparatus according to claim 1, wherein the recording unit has an inkjet head that ejects ink. 7. The sheet conveying apparatus according to claim 6, wherein the ink jet head records an image with ink ejected by thermal energy.