JP2002145474A - Conveying device and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveying device to suppress vibration of a conveyance belt during conveyance and be high in reliability to stably convey paper sheets and to provide a recording device. SOLUTION: By providing a belt attraction means 37 to attract a conveyance belt 31 by an electric force, the conveyance belt 31 is attracted to the belt attraction means 37, whereby vibration of the belt during conveyance can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport device using a transport belt and a recording device for recording an image on a transported object transported by the transport device. Is applied to a transporting device that transports the transported object by electrostatically attracting the transported object to the transporting belt, and a recording apparatus including the transporting device.

[0002]

2. Description of the Related Art Conventionally, as this type of recording apparatus, there is a recording apparatus such as a printer of an ink jet system.

[0003] In general, an ink jet recording apparatus is an apparatus that performs recording on a recording medium by discharging ink from a recording head. The recording head can be easily downsized, high-definition images can be recorded at high speed, running costs are low, and the non-impact method reduces noise and uses multi-color inks for color images. Is easy to record.

[0004] Above all, a full line type apparatus using a line type recording head in which a number of nozzles are arranged in the paper width direction can further increase the recording speed.

However, in a full-line type apparatus, the distance from the recording head at the most upstream position to the recording head at the most downstream position becomes considerably long.
The recording sheet is lifted in the recording area, which causes disturbance of the recorded image, jams, and the like.

Therefore, as a means for urging the recording sheet downward so that the recording sheet does not float, a method of applying a voltage to an electrode provided on a transport belt to generate an electric force and adsorbing the recording sheet is generally known. .

In such an ink jet recording apparatus,
The recording sheet fed by the sheet feeding device is conveyed while being adsorbed and held on the upper surface of the transport belt by an attraction force generating means provided on the transport belt, and an image is recorded by a recording head in a recording area.

FIG. 9 is a schematic diagram of the entire recording apparatus according to the prior art. A recording device having an automatic paper feeder
It comprises (I) a paper feed unit, (II) a conveyor belt unit, (III) a recording head unit, and (IV) a paper discharge unit. Each unit will be described below with reference to FIG.

(I) Paper Feeding Unit In the drawing, a paper feeding unit 102 includes a pressure plate 1 on which a recording sheet P is stacked.
21 and a feeding rotating body 122 for feeding the recording sheet P,
It is configured to be attached to the base 120. The pressure plate 121 is rotatable about a rotation axis a coupled to the base 120, and is urged by a pressure plate spring 124 to the feeding rotating body 122.

A separation pad 125 made of a material having a large coefficient of friction, such as artificial leather, for preventing double feeding of the recording sheet P is provided at a portion of the pressure plate 121 opposed to the feeding rotating body 122.

Further, a separation claw 126 for covering a corner of the stacked recording sheets P in one direction and separating the recording sheets P one by one, and a contact between the pressure plate 121 and the feeding rotary body 122 are provided on the base 120. Is provided.

In the above configuration, in the standby state, the release cam pushes the pressure plate 121 down to a predetermined position, and the contact between the pressure plate 121 and the feeding rotating body 122 is released.

In this state, when the driving force of the transport roller 132 is transmitted to the feed rotating body 122 and the release cam by a gear or the like, the release cam separates from the pressure plate 121 and the pressure plate 121 rises, and the feed rotation is performed. The body 122 contacts the recording sheet P.

The recording sheet P is picked up by the rotation of the feeding rotary member 122 and starts to be fed.
The sheets are separated one by one by 26 and sent to the conveyor belt unit 103.

The feed rotator 122 rotates until the recording sheet P is sent to the conveyor belt section 103, and then rotates again.
In this state, the contact between the feed roller 122 and the feed rotator 122 is released, and the driving force from the transport roller 132 is cut off.

Reference numeral 190 denotes a feeding rotating body for manual paper feeding. The recording sheet P set on the manual feed tray 191 is fed to the feeding rotator 190 in accordance with a recording command signal from a computer.
And transports the paper to the transport belt unit 103.

(II) Transport Belt Portion The transport belt portion 103 has a transport belt 131 that attracts and transports the recording sheet P, and a PE sensor (not shown). The transport belt 131 is driven by a drive roller 134 and is wound around a transport roller 132 as a driven roller and a pressure roller 135.

The transport roller 132 and the drive roller 13
4 is rotatably attached to the platen 130, and the pressure roller 135 is rotatably attached to the other end of the arm 150, one end of which is swingably attached to the platen 130, and the arm 150 is pressed by the spring 151. The tension is applied to the transport belt 131.

The platen 130 is provided with a conveyor belt 131.
, And serves to regulate the downward displacement of the conveyor belt 131.

A pinch roller 133 driven by the conveyor belt 131 is provided at a position facing the conveyor roller 132. The pinch roller 133 guides the recording sheet P to the recording head unit 107 by being pressed against the conveying belt 131 by a spring (not shown).

An upper guide 127 and a lower guide 128 for guiding the recording sheet P are provided at the entrance of the conveying belt 103 to which the recording sheet P is conveyed. Further, the upper guide 127 is provided with a PE sensor lever 123 for transmitting detection of the leading and trailing edges of the recording sheet P to a PE sensor (not shown).

Further, a recording head unit 107 for forming an image based on image information is provided downstream of the conveying roller 132 in the recording sheet conveying direction.

In the above configuration, the recording sheet P conveyed to the conveyor belt section 103 is guided by the upper guide 127 and the lower guide 128, and is sent to a pair of rollers including a conveying roller 132 and a pinch roller 133. At this time, the leading end of the conveyed recording sheet P is
3, the recording position of the recording sheet P is obtained.

The recording sheet P is conveyed by the rotation of a conveyor belt 131 via a conveyor roller 132 by a paper feed motor described later.

(III) Recording Head Unit The recording head unit 107 includes four line-type ink jet recording heads in which a plurality of nozzles are arranged in a direction intersecting with the conveying direction of the recording sheet P. 107K (black), 107C (cyan), 107M (magenta), 107Y (yellow) from upstream in the transport direction
Are provided on the head holder 170 at predetermined intervals in the order of.

Recording heads 107K, 107C, 107
M and 107Y can apply heat to the ink by a heater or the like. Then, the ink causes film boiling due to the heat, and the recording heads 107K, 107K are driven by pressure changes caused by growth or shrinkage of bubbles due to the film boiling.
Ink is ejected from the nozzles 07C, 107M, and 107Y to form an image on the recording sheet P.

The head holder 170 has one end on the shaft 1.
The protrusion 171 provided at the other end and the rail 173 are engaged with each other so as to be rotatable by 72, and the distance (paper interval) between the nozzle surface and the recording sheet P is defined.

(IV) Discharge Unit The discharge unit 104 includes a discharge roller 141 and a spur 142, and the recording sheet P, on which an image is formed by the recording head unit 107, is transmitted to the discharge roller 141 and the spur 142. The sheet is nipped, conveyed, and discharged to the discharge tray 143.

The paper discharge roller 141 is driven by transmitting the rotational force of the drive roller 134 by a transmission means (not shown).

It should be noted that the outer periphery of the spur 142 has a pointed uneven surface, and prevents the ink of the recorded image from being transferred to the spur 142 when rolling on the recording surface after recording.

Next, the structure and operation of the suction transfer of the transfer device according to the prior art will be described with reference to FIGS.

FIG. 10 is a schematic configuration diagram of a transfer device according to the prior art.

In the figure, reference numeral 131 denotes a transport belt which moves while adsorbing and holding the recording sheet P.
It is made of a synthetic resin such as polyethylene or polycarbonate having a thickness of 2 mm, and has an endless belt shape.

Reference numeral 152 denotes a power supply brush connected to a high-voltage power supply (not shown) that generates a predetermined high voltage, and is provided to be joined to the transport belt 131.

The conveying belt 131 is provided with an attraction force generating means 136 which will be described later, and the power supply brush 152 applies a voltage of about 0.5 kV to 10 kV to the attraction force generating means 136 so that the attraction force is applied to the conveying belt 131. Force is generated.

The transport roller 132, the drive roller 134, and the pressure roller 135 are rollers that support the transport belt 131 and apply an appropriate tension. The drive roller 134 is connected to a paper feed motor 160.

A paper pressing roller 140 as pressing means for pressing the recording sheet P against the transport belt is rotatably mounted on the paper pressing roller support member 139.
The paper pressing roller support member 139 is attached with the rotation axis of the pinch roller 133 as the center of rotation, and the paper pressing roller 140 is moved by a biasing means (not shown) to the transport belt 13.
It is biased to one side.

Reference numeral 138 denotes a cleaning roller pair which is provided so as to be pressed between the transport belt 131 and can absorb ink to remove stains such as ink adhered to the transport belt 131 and prevent deterioration in durability. Small pore size (preferably 10 μm to 30 μm)
It is formed of spontaneous sponges.

Reference numeral 137 denotes a discharging brush which is a discharging means for the conveyor belt 131.

In the above-described configuration, the recording sheet P conveyed from the paper feeding unit is fed by the conveying roller 132 and the pinch roller 13.
3 are held on the conveyor belt 131 and pressed against the conveyor belt 131 by the paper pressing roller 140.

Then, the electric force generated by the attraction force generating means 136 to which a voltage is applied from the power supply brush 152 is used.
The recording sheet P is attracted to the flat portion of the conveyor belt 131.

Recording sheet P adsorbed on conveyor belt 131
Is led to the recording head unit 107, and the recording head 107
While being recorded by K, 107C, 107M, and 107Y, the sheet is conveyed in the direction of arrow A by the paper feed motor 160 and the drive roller 134.

The transport belt 131 is the cleaning roller 1
After cleaning at 38, the charge is removed by the charge removing brush 137.

Next, the attraction force generating means 136 will be described with reference to FIGS.

FIG. 11 is a schematic configuration diagram of the transport belt as viewed from the direction of arrow f in FIG. 10, and shows an electrode pattern and the like of suction force generating means provided on the transport belt. FIG. 12 is a cross-sectional view of the conveyor belt viewed from the direction of arrow a in FIG.
FIG. 13 is a cross-sectional view of the transport belt viewed from the direction of arrow b in FIG.

In the drawing, an attraction force generating means 136 is provided inside the conveyor belt 131. Attraction force generating means 1
Numeral 36 denotes an electrode plate 136a made of a conductive metal and an earth plate 136b. As shown in the drawing, each of the teeth has a comb-like shape and is conveyed so that it faces in a direction intersecting with the belt conveying direction. 131 are provided.

Power-supplied portions 136a 'each having an exposed pattern are provided at both ends in the moving direction of the conveyor belt 131.
136b 'is the direction in which the electrodes 136a, 136
The conductive power supply brushes 152 are provided with a distance longer than the width of b and are in contact with each other at a predetermined pressure.

The power supply brush 152 applies a positive or negative voltage from a high-voltage power supply (not shown) to the power-supplied portion 136a 'of the electrode plate 136a. Also, the earth plate 136b
Of the power-supplied portion 136b 'is grounded.

As shown in FIGS. 12 and 13, the conveying belt 131 has a suction force generating means 136 composed of an electrode plate 136a made of a conductive metal and an earth plate 136b in a suction force generation area, and a base layer 136c. And the surface layer 136d is provided in a protected manner in a sandwiched manner. The base layer 136c and the surface layer 136d are made of a synthetic resin such as polyethylene and polycarbonate.

When a voltage is applied to the electrode plate 136a, an electric force is generated in the direction of the arrow, and electric lines of force are formed as shown in the figure. Then, the electrode plate 136a and the earth plate 136b
A suction force is generated at a position above the transport belt 131 due to the potential difference between the recording sheet P and the recording sheet P. A charge (surface potential) having the same polarity as the voltage applied to the electrode plate 136a is generated on the recording surface of the attracted recording sheet P.

The electrode plate 136a and the earth plate 136b
In a portion where there is no conductive metal, the suction force received by the recording sheet P becomes the weakest.

When a large amount of ink is ejected onto the recording sheet P, the recording sheet P swells, and cockling occurs. Also in this case, the recording sheet P is attracted to the conveyor belt 131 by the attraction force of the attraction force generating means 136, so that the recording sheet P does not float to the recording head 107 side, and the recording heads 107K, 107C,
Stable recording can be performed without contact between the recording sheet P and the recording sheet P.

Further, the cock ring is connected to the conveyor belt 131.
By causing the recording sheet P to be dispersed and generated in the area having the weakest attraction force (the part without the conductive metal between the electrode plate 136a and the earth plate 136b), the floating of the recording sheet P toward the recording head unit 107 is minimized. Can be suppressed.

Further, even when the end of the recording sheet P is wavy or curled due to changes in environment such as temperature and humidity, the recording sheet P is pressed against the transport belt 131 by the paper pressing roller 140. Since the sheet can be conveyed to the suction force generating area in a state where waving and curling have been removed, stable suction can be performed in the recording head unit 107.

FIG. 14 is a perspective view schematically showing the structure of a platen according to the prior art.

The platen 130 is a platen base 130
a is provided with ribs 130b arranged at arbitrary intervals in parallel with the belt conveying direction. Each rib 130b
Is located below the plane connecting the drive roller 134 and the upper surface of the transport roller 132 by 0 to 0.5 mm, and regulates the transport belt 131 so as not to be lower than the upper surface of the rib 130b when the belt rotates.

Also, the electric force generated by applying a voltage to the conveyor belt 131 causes the conveyor belt 131 to be attracted to the entire surface of the platen 130, thereby increasing the rotational load and making it impossible to rotate or impossible to carry accurately. Is preventing that.

[0058]

However, in the case of the above-described prior art, the following problems have occurred.

In order to obtain high-definition image quality, the inkjet recording apparatus is required to convey the recording sheet with high precision while keeping the distance between the recording sheet and the recording head close and constant. In particular, in a 1-pass high-speed recording apparatus using a line head, this becomes a factor directly affecting the image quality.

In the recording apparatus according to the prior art as described above, the conveying belt immediately below the recording head is suspended by the conveying roller 132 and the driving roller 134. However, there has been a problem such as deterioration of the device.

The transport belt 131 is connected to the electrode plate 136.
a and an earthing plate 136b, a comb-teeth generating means 136, a base layer 136c, and a surface layer 136d.
The layers are joined to each other by means such as an adhesive or heat welding.

When the transport belt 131 is left for a long time in a state of being wound around the transport roller 132, the drive roller 134, and the pressure roller 135, a difference in curvature inherent in the material causes a difference in curvature between the rollers in contact with the respective rollers. Habits remain.

When the carrying operation is started, the carrying rollers 132
And the conveyor belt 131 suspended by the drive roller 134,
It is pulled in the transport direction by the tension applied by the pressure roller 135.

However, as shown in FIG. 15, the habit shape remains in the habited portion, and the recording head 1
0.5mm to 1.0m at the position opposite to 07
There has been a problem that m waves occur and the image quality deteriorates.

The recording section of the recording sheet P is transferred to the transport belt 13
Although a method of controlling so as not to be located in the first residual habit shape portion is also conceivable, in the ink jet recording apparatus, the interval between the recording head portion 107 and the recording sheet P is 1.0 mm to
Since it is as narrow as 1.5 mm, depending on the shape of the habit, the nozzle surface may be rubbed, causing a phenomenon such as destruction of the nozzle portion, color mixing, or sticking due to a reaction between inks, which may make recording impossible.

As shown in FIG. 16, a method may be considered in which a spur is provided at a position facing each nozzle to stretch the conveyor belt. It is not suitable for a full-line type high-speed ink jet recording apparatus because a problem such as high voltage leakage due to deterioration of the surface layer occurs.

An object of the present invention is to provide a highly reliable transport device and a recording device capable of suppressing the vibration of the transport belt during transport and stably transporting the transported object.

[0068]

According to one aspect of the present invention, there is provided a transporting apparatus for transporting an object by adsorbing an object to be transported by a belt provided with an electrode. It is characterized by comprising: an application unit that generates an electric force by applying a voltage; and a belt suction unit that suctions the belt using the electric force.

One aspect of the recording apparatus according to the present invention is as follows.
In a recording apparatus that adsorbs and conveys an object to be conveyed by a belt provided with electrodes and performs recording on the object to be conveyed by a recording unit, an application unit that applies a voltage to the electrode to generate an electric force; And a belt suction means for sucking the belt using electric force.

According to the above configuration, it is possible to provide a highly reliable transport device and a recording device capable of suppressing the vibration of the belt during transport and stably transporting the transported object.

[0071]

Embodiments of the present invention will be described below with reference to the drawings.

<First Embodiment> A preferred embodiment of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention thereto unless otherwise specified. Absent.

With reference to FIGS. 1 to 5, a transfer device according to an embodiment of the present invention will be described.

FIG. 1 is a schematic perspective view of a main part of a transfer apparatus according to an embodiment of the present invention, and FIG. 2 is a schematic structural view of a main part of the transfer apparatus according to the embodiment of the present invention. FIG. 3 is a schematic sectional view of the belt suction means according to the embodiment of the present invention.

The transport belt 31 provided with the suction force generating means 36 (the same configuration as that of the prior art) by the comb electrode is driven by the drive roller 34 and wound around the transport roller 32 and the pressure roller 35 which are driven rollers. ing.

The transfer roller 32 and the drive roller 34 are rotatably mounted on the transfer device frame 30, and the pressure roller 35 is rotatably mounted on the other end of the arm 50, which has one end swingably mounted on the transfer device frame 30. Arm 5
0 is pressed by the spring 51 so that the transport belt 31
Is applied with tension (19.6N).

A pinch roller 33 driven by the conveyor belt 31 is provided at a position facing the conveyor roller 32. The pinch roller 33 introduces the recording sheet P by being pressed against the transport belt 31 by a spring (not shown). The pinch roller 33 is electrically connected to a main body frame (not shown), so that the surface layer 36 d of the transport belt 31 is formed.
To remove the charge stored in the

At the entrance of the conveyor belt 31 to which the recording sheet P is conveyed, an upper guide 2 for guiding the recording sheet P is provided.
7 and a lower guide 28 are provided. Further, the upper guide 27 is provided with a PE sensor lever 23 for transmitting the detection of the leading edge and the trailing edge of the recording sheet P to a PE sensor (not shown).

Further, a recording head 7 for forming an image based on image information is provided downstream of the transport roller 32 in the recording sheet transport direction.

In the above configuration, the recording sheet P conveyed to the conveyor belt 31 is supplied to the upper guide 27 and the lower guide 2.
8 and is sent to a roller pair of a transport roller 32 and a pinch roller 33. At this time, the leading end of the conveyed recording sheet P is detected by the PE sensor lever 23 to determine the recording position of the recording sheet P.

Then, the recording sheet P is conveyed by the rotation of the conveying belt 31 via the conveying roller 32 by a paper feed motor described later.

Next, the most characteristic belt suction means of the present invention will be described.

The belt suction means 37 comprises a convex portion 37a, a sliding surface 37b, and a low friction layer 37c, and a plurality of belt suction devices are provided on the transport device frame 30 so as to intersect the belt transport direction.

Each of the belt suction means 37 is provided at a position opposed to the corresponding recording head 7 with the transport belt 31 interposed therebetween, and the sliding surface 37b and the nozzle surface (face surface) of the recording head 7 are different from each other. Be parallel.

The protruding portion 37a is made of a conductive material in order to obtain a sufficient suction force.

The sliding surface 37b is a surface that is attracted to and slides on the conveyor belt 31 and has a predetermined width in the conveying direction. Note that the respective sliding surfaces 37b of the belt suction means 37 are disposed so as to be located on the same plane.

The low friction layer 37c is made of a low friction material such as a Teflon (registered trademark) film or a high molecular weight polyethylene film (thickness: 100 μm, coefficient of friction:
0.2), the friction between the conveyor belt 31 and the sliding surface 37b is reduced, the rotational load during rotation is stabilized, and the conveyance accuracy is ensured.

In the embodiment of the present invention, the principle of suppressing the flutter of the transport belt during the transport and the ripple of the transport belt due to the influence of the residual habit shape will be described.

When the recording sheet P is transported, a high voltage (0.5 kV to 10 kV) is applied to the transport belt 31 provided with the comb electrodes to generate an electric force, and the recording sheet P is attracted to the upper surface of the transport belt 31. The lower surface is the convex portion 3 of the belt suction means 37.
7a sucks or adsorbs the vertical displacement, thereby realizing stable conveyance.

By modeling the transport belt 31 and the convex portion 37a, it can be regarded as a capacitor connected in series as shown in FIG. 4A, so that the suction force between the electrode plate 36a and the convex portion 37a is obtained. The following relational expression holds for F.

F = (εS / 2d ² ) × (V−V ₁ −V ₂ ) ² ... V is a high voltage applied to the conveyor belt 31, V ₁ is a partial pressure applied to the base layer 36 c, V ₂ is the partial pressure applied to the low friction layer 37c, ε is the dielectric constant of the space formed by the base layer 36c and the low friction layer 37c, S is the area of the upper surface of the projection 37a, and d is the distance between the electrode plate 36a and the projection 37a. Is the distance.

As can be seen from the above equation, the suction force F
Is inversely proportional to the distance between the electrode plate 36a and the convex portion 37a, that is, the square of the thickness of the base layer 36c and the low friction layer 37c,
It is proportional to the width (area) of the upper surface of the convex portion 37a, and increases / decreases in proportion to the square of the voltage (voltage applied to the space) obtained by subtracting the partial pressure of the base layer 36c and the low friction layer 37c from the applied voltage.

FIG. 4B shows the area S of the upper surface of the projection 37a.
Is a graph showing the increase and decrease of the attraction force F when the applied voltage V and the distance d are changed, where it is understood that the smaller the distance d, the stronger the attraction force.

The upward repulsive force acting on the transport belt 31 in the transport state (the direction opposite to the belt suction means 37) (the restoring force of the residual habit shape and the resultant force such as fluttering during transport) is smaller than the suction force F. At this time, the conveyor belt 31 is always attracted to the belt suction means 37.

Further, the suction force can be increased by increasing the partial pressure acting on the space formed by the base layer 36c and the low friction layer 37c. That is, the electric capacity of the base layer 36c and the low friction layer 37c may be increased, and the partial pressure applied to them may be reduced.

As described above, the base layer 36c and the low friction layer 3
By reducing the thickness of 7c and using a material having a high dielectric constant, it becomes possible to increase the attractive force.

In this embodiment, the belt suction means 3 provided opposite to each of the plurality of recording heads 7 is provided.
7, the conveying roller 32 and the driving roller 34
Are configured to be flush with the plane connecting the upper surfaces of.

The width of the convex portion 37a of the belt suction means 37 in the transport direction is set to 15 mm (the width in the direction intersecting the transport direction is the same as the nozzle width), and the base layer 36c has a thickness of 120 mm.
The μm polyimide and the low friction layer 37c were made of 100 μm thick Teflon.

In the above configuration, the applied voltage is 1.5 kV
By doing so, in the transport belt 31 according to the present embodiment, it is possible to obtain a sufficient suction force in order to suppress fluttering during transport and waving due to the influence of the residual habit shape.

However, if the suction force is too strong, the transport belt 31 sticks to the belt suction means 37,
Since the rotation load may increase and the rotation may stop, it is necessary to optimize the suction force acting in the vertical direction and the dynamic friction force between the base layer 36c and the low friction layer 37c.

If the friction of the base layer 36c is too low, the friction with the drive roller 34 is reduced and slippage occurs, and high-precision conveyance becomes impossible. is there. As for the low friction layer 37c, it is desirable that the material has a high dielectric constant, a small coefficient of friction, and excellent wear resistance.

FIG. 5 is a graph showing a change in the distance between the recording head and the transport belt when the transport belt having the residual habit shape is driven at a high speed. FIG. FIG. 5B shows the measurement results of the transport device according to the present embodiment.

In the transfer apparatus according to the prior art shown in FIG. 5A, the influence of the residual habit shape caused by the transfer roller, the drive roller and the pressure roller appears. Immediately after that, the transfer belt is displaced to near the rib upper surface. You can see that it is. This is the waving of the transport belt due to the influence of the residual habit shape.
In addition, a small swell during the large displacement is fluttering during conveyance.

The displacement of the waving and flapping during the transfer is 1
mm, and it is difficult to convey the recording sheet while keeping a certain distance from the recording head. In addition, it is impossible to reduce the distance between the recording head and the transport belt in consideration of the influence of cockling due to the recording operation.

On the other hand, in the conveying apparatus according to the present embodiment shown in FIG.
7 and slide, the displacement between the recording head 7 and the conveyor belt 31 can be suppressed to 0.1 mm or less.

As described above, according to the conveying apparatus according to the present embodiment, the distance between the recording head and the recording sheet is not affected by the influence of the residual habit shape of the conveying belt and the flapping during the conveyance from the start of the operation. Can be recorded on the recording sheet while keeping the constant.

Since the transport belt 31 provided with the comb electrodes has the electrode plate 36a inside the belt, the recording sheet is adsorbed on the recording head 7 side (upper surface), and the belt is attracted on the opposite side (lower surface). Even if the suction is performed with the means 37, the suction force of the means 37 is hardly affected.

<Second Embodiment> A second embodiment will be described with reference to FIGS. In the second embodiment, the positional relationship between the belt suction means and the electrode, that is, the positional relationship between the recording head and the electrode is defined.

FIG. 6 is a distribution curve of the surface potential of the surface layer in the transport direction generated when positive and negative high voltages are respectively applied to the left and right electrode portions. A maximum potential is generated at the center of the electrode to which the positive voltage is applied, and a minimum potential is generated at the center of the electrode to which the negative voltage is applied. In the measurement result, the distribution has a substantially sinusoidal waveform. A similar distribution was measured on the base layer side, and as a result,
The suction force described in the first embodiment is generated, and the transport belt can be transported stably.

When the surface potential E at the head position (corresponding to the position of the convex portion) in the first row in the uppermost stream in the transport direction is expressed by the following equation, the following relational expression is established.

E = E _over × cos (PS × π / (H _point + H _space ) × t) In the above formula, PS is the belt conveyance speed, E _over is the maximum surface potential, H _point is the electrode width, H _space is the distance between the electrodes.

However, as can be seen from the above formula and FIG. 6, since the attraction force changes due to the potential difference, when the electrode plate and the earth plate provided on the conveyor belt are regularly arranged in a comb-tooth shape, the electrode plate and the earth plate are arranged at arbitrary intervals. distribution of the potential of the convex portion of the deployed platen is different, the second column of the surface potential is located at a distance L ₂ E can be expressed by the following equation.

E = E _over × cos (PS × π / (H _point + H _space ) × (t−L ₂ / PS)) E = E _over × cos (PS × π / (H _point + H _space ) × t−π × L ₂ / (H _poin t + H _space ) ・ ・ ・ Therefore, in order to reduce the operating load fluctuation caused by the attraction force due to the potential difference, the variation amount of the total sum of the absolute values of the potential at each head position must be In this embodiment, a plurality of recording heads (here, five color recording heads are exemplified) are arranged at intervals of the driving roller circumferential length in consideration of conveyance accuracy. The projections 30a of the platen 30 which are arranged at equal intervals and face each of these recording heads
Are also arranged at equal intervals at the drive roller circumferential length interval.
In this case, considering the relationship between the positive and negative of the surface potential and the attraction force, the electrode pattern (H _point + H
_Space ) makes it possible to minimize (minimize) the fluctuation of the operating load generated between the transport belt 31 and the convex portion 30a of the platen 30 during the operation of the transport belt. In the following formula, L is the head conveyance interval, N is an integer, and _nh is the number of heads.

Π × L / (H _point + H _space ) = π × (N + 1 / n _h ) FIG. 7 and FIG. 8 show load variation curves due to electrostatic force when the pattern of the comb electrode is changed. Is shown. FIG. 7 shows the recording position (the position of the convex portion of the platen facing each recording head) at a position satisfying the above formula, and the pattern of the comb-teeth electrodes is matched. It can be seen that the operating load fluctuation generated between the belt 31 and the convex portion 30a of the platen 30 is very small. On the other hand, FIG. 8 shows that the pattern of the comb-teeth electrode is set to a value that does not satisfy the above formula, even at the same recording position. It can be seen from FIG. 8 that the load fluctuation is irregular and greatly different.

As described above, by optimizing the recording position (the position of the convex portion of the platen facing each recording head) and the pattern of the comb-teeth electrodes, the convex position of the transport belt and the platen can be reduced during the operation of the transport belt. It is possible to minimize the fluctuation of the operating load generated between the units, and to realize stable conveyance accuracy.

<Third Embodiment> In the above embodiment, a plurality of belt suction means 37 are provided to intersect with the belt transport direction, and each of them faces the corresponding recording head 7 with the transport belt 31 interposed therebetween. It is located at the position,
The configuration is not limited to the above configuration as long as a suction force sufficient to suppress the vibration of the belt during conveyance can be generated.

For example, the belt suction means 37 may be arranged parallel to the belt conveying direction. Alternatively, the recording sheet P
Alternatively, the width of the transport belt 31 is made sufficiently wider than the width of the recording head 7, and the belt suction means 37 is provided so as to suck the side end of the transport belt 31. Belt suction means 37 on the side
Can also be provided.

In the above embodiment, the convex portion 37a of the belt suction means 37 is made of a conductive metal, but may be made of a conductive material in which a resin is coated with a conductive paint or the like instead of the conductive metal. .

Although the low friction layer 37c is made of a film such as Teflon, a low friction material may be coated instead of the film. It is expected that adjustment in the thickness direction will be required during coating.

<Other Embodiments> In the above-described embodiments, an ink-jet recording apparatus for color recording using a plurality of recording heads for recording with inks of different colors has been described as an example. The recording method is not limited to this. For example, an ink jet recording apparatus using one recording head, or an ink jet recording apparatus for gradation recording using a plurality of recording heads that record with the same color and different density inks may be used. The present invention can be applied similarly regardless of the number of heads, and can achieve the same effect.

Further, as the recording means (recording head), a cartridge type in which a recording head and an ink tank are integrated, a recording head and an ink tank which are separated and connected to each other by an ink supply tube, and the like can be used. Regardless of the configuration of the recording means and the ink tank, the same can be applied and the same effect can be achieved.

When the present invention is applied to an ink jet recording apparatus, for example, the present invention can be applied to an apparatus using a recording means using an electromechanical transducer such as a piezo element.
In particular, the present invention brings about an excellent effect in an ink jet recording apparatus using a recording means of a method of discharging ink using thermal energy. According to such a method, it is possible to achieve higher density and higher definition of recording.

Further, the present invention can be effectively applied to a so-called serial type recording apparatus which performs recording while moving the recording head in a direction orthogonal to the recording medium conveyance direction. Alternatively, even if the recording head is a full-line type recording apparatus having a length corresponding to the maximum width of a recording medium on which recording can be performed, such a recording head may have a length determined by a combination of a plurality of recording heads. It may be either a configuration that satisfies the condition or a configuration as one recording head that is integrally formed. In addition, even in the case of the serial type described above, a recording head fixed to the apparatus main body, or an exchange that can be electrically connected to the apparatus main body or supplied from the apparatus main body by being attached to the apparatus main body. The present invention is also effective when a print head of a free chip type or a print head of a cartridge type in which an ink tank is provided integrally with the print head itself is used.

In addition to the above, the above-described ink jet recording apparatus may be used as an image output terminal of an information processing apparatus such as a computer, or may be an ink jet recording apparatus capable of mounting a scanner other than a recording head on a carriage. It may be a copying machine combined with an input / output device, a reader, or the like, or a facsimile machine having a transmission / reception function.

In the above-described embodiment, the ink jet recording method is exemplified as the recording method. However, the recording method is not limited to this.
Furthermore, an impact recording method such as a wire dot recording method or a recording method such as another electrophotographic method can be applied.

[0126]

As described above, according to the present invention,
Since the conveyance belt suction means for sucking the conveyance belt by the electric force is provided, it is possible to suppress the flutter of the conveyance belt at the time of conveyance and the waving of the conveyance belt due to the influence of the residual habit shape, and to stably convey the sheet.

Further, if the belt suction means is made of a conductive material, a stronger suction force can be generated.

Further, by providing the conveyance belt and the belt suction means so as to be attracted and slid, the vibration of the conveyance belt can be further suppressed.

At this time, if a sliding portion made of a low-friction material is provided at a position where the belt suction means slides with the conveyor belt, the load when the conveyor belt slides is reduced, which is efficient.

Further, if the sliding portion is made of a dielectric material, an even stronger suction force can be generated.

In a recording apparatus provided with recording means for recording an image on a sheet conveyed by the above conveying apparatus, the sheet can be stably conveyed by the belt suction means. The distance can be kept constant, and high-speed and high-definition image recording becomes possible.

[Brief description of the drawings]

FIG. 1 is a schematic configuration perspective view of a main part of a transport device according to an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a main part of the transport device according to the embodiment of the present invention.

FIG. 3 is a schematic sectional view of a belt suction unit according to the embodiment of the present invention.

FIG. 4A is an explanatory diagram when a transport belt and a convex portion are modeled. (2) is a graph showing the increase and decrease of the suction force F when the applied voltage V and the distance d between the electrode plate and the convex portion are changed.

FIG. 5 is a graph showing a change in the distance between the recording head and the conveyance belt when a conveyance belt having a residual habit shape is driven at a high speed, and FIG. 5A is a graph showing measurement results of a conveyance device according to the related art. is there. (2) is a graph of a measurement result in the transport device according to the present embodiment.

FIG. 6 is a measurement graph of the surface potential of the conveyor belt with comb-tooth electrodes according to the second embodiment.

FIG. 7 is a graph of an operating load variation when an optimal arrangement according to the second embodiment is performed.

FIG. 8 is a graph of an operating load variation when the optimal arrangement according to the second embodiment is not performed.

FIG. 9 is a schematic configuration diagram of the entire recording apparatus according to the related art.

FIG. 10 is a schematic configuration diagram of a transfer device according to a conventional technique.

11 is a schematic configuration diagram of the transport belt as viewed from the direction of arrow f in FIG.

12 is a cross-sectional view of the transport belt as viewed from the direction of arrow a in FIG.

13 is a cross-sectional view of the transport belt as viewed from the direction of arrow b in FIG.

FIG. 14 is a schematic configuration perspective view of a platen according to the related art.

FIG. 15 is an explanatory diagram of a residual habit shape of the transport belt.

FIG. 16 is an explanatory diagram of a method of providing a spur and stretching a transport belt.

[Explanation of symbols]

 7 Recording Head 23 PE Sensor Lever 27 Upper Guide 28 Lower Guide 30 Conveyor Frame 31 Conveyor Belt 32 Conveyor Roller 33 Pinch Roller 34 Drive Roller 35 Pressure Roller 36 Attraction Force Generating Means 36a Electrode Plate 36b Ground Plate 36c Base Layer 36d Surface Layer 37 Belt Suction means 37a Convex portion 37b Sliding surface 37c Low friction layer 50 Arm 51 Spring 101 Recording device 102 Paper feed unit 103 Transport belt unit 104 Paper discharge unit 107 Recording head unit 107K Black recording head 107C Cyan recording head 107M Magenta recording Head 107Y Yellow recording head 120 Base 121 Pressure plate 122 Feed rotator 123 PE sensor lever 124 Pressure plate spring 125 Separation pad 126 Separation claw 127 Upper guide 128 Lower guide 130 Platen 130a Platen base 130b Rib 131 Transport belt 132 Transport roller 133 Pinch roller 134 Drive roller 135 Pressure roller 136 Attraction force generating means 136a Electrode plate 136b Ground plate 136a ', 136b' Power receiving part 136c Base layer 136d Surface layer 137 Cleaning brush 138 Cleaning 139 Paper press roller support member 140 Paper press roller 141 Paper discharge roller 142 Spur 143 Paper discharge tray 150 Arm 151 Spring 152 Power supply brush 153 Power supply brush support member 170 Head holder 171 Projection 172 Axis 173 Rail 190 Feed rotator 191 Manual feed Tray P Recording sheet

Claims (18)

[Claims] 1. A transporting apparatus for transporting an object by adsorbing an object to be transported by a belt provided with electrodes, comprising: an applying unit configured to apply a voltage to the electrodes to generate an electric force; A transport device, comprising: belt suction means for sucking a belt. 2. The transport according to claim 1, wherein the electrodes are provided in a comb-shape crossing the transport direction of the belt, and a positive or negative voltage is applied by the application unit. apparatus. 3. The conveying device according to claim 1, wherein the belt suction means is provided on a side opposite to a surface of the belt on which the object to be conveyed is attracted. 4. The transfer device according to claim 1, wherein the belt suction means has conductivity. 5. The transfer device according to claim 1, wherein the belt is slid while attracting the belt suction means. 6. The transport device according to claim 5, wherein a sliding portion made of a low-friction member is provided at a position of the belt suction unit that slides with the belt. 7. The transfer device according to claim 6, wherein the sliding portion is made of a dielectric. 8. A recording apparatus in which an object to be conveyed is attracted and conveyed by a belt provided with electrodes, and recording is performed on the object by recording means, wherein a voltage is applied to the electrode to generate an electric force. A recording apparatus, comprising: an application unit; and a belt suction unit that suctions the belt using the electric force. 9. The recording apparatus according to claim 8, wherein the belt suction unit is provided at a position facing the recording unit. 10. A recording apparatus for adsorbing and conveying an object to be conveyed by a belt provided with electrodes and performing recording on the object to be conveyed by a plurality of recording means arranged along the conveying direction of the belt, An application unit that applies an electric voltage to the electrode to generate an electric force, and a belt suction unit that is disposed at a position facing the recording unit and suctions the belt using the electric force. When the interval of the recording means with respect to the transport direction is L, the width of the electrode is H _point , the distance between the electrodes is H _space , the number of the recording means is n _h , and N is an integer, π × L / (H _point
+ H _space ) = π × (N + 1 / n _h ). 11. The electrode according to claim 9, wherein the electrode is provided in a comb shape crossing the conveying direction of the belt, and a positive or negative voltage is applied by the application unit. Recording device. 12. The recording apparatus according to claim 9, wherein the belt suction means is provided on a side opposite to a surface of the belt on which the object to be conveyed is sucked. apparatus. 13. The recording apparatus according to claim 9, wherein said belt suction means has conductivity. 14. The recording apparatus according to claim 9, wherein the belt is slid while attracting the belt suction means. 15. The recording apparatus according to claim 14, wherein a sliding portion made of a low-friction member is provided at a position where the belt suction unit slides with the belt. 16. The recording apparatus according to claim 15, wherein said sliding portion is made of a dielectric. 17. The recording apparatus according to claim 8, wherein the recording unit is a recording head that discharges ink to perform recording on a conveyed object. 18. The recording head according to claim 17, wherein the recording head supplies a current to the electrothermal transducer in response to a signal, and discharges ink using thermal energy generated by the electrothermal transducer. Recording device.