JP2000247476A - Carrying belt and belt carrying device as well as image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To keep a suction force for a recording sheet end similar to suction forces to the other portions by providing a plurality of opposite electrodes with regions formed slantly with respect to the carrying width direction of a belt member. SOLUTION: A suction generation means 36 provided on a carrying theft 31 consists of electrode plate portions 36a serving as opposite electrodes made of conductive metal and earth plate portions 36b both of which form comb-like patters respectively. Each pattern has an independent tooth-like portion where each recessed portion is fitted to each protruding portion so that directions of the electrodes face each other in the direction slantly with respect to the belt carrying direction. At both ends of the belt 31 in the carrying width direction, terminals 36a', 36b' are provided to have a longer distance than the width of each of the electrodes 36a, 36b in the belt moving direction, and each power feeding brush 52 is brought into contact with each of the terminals 36a', 36b' under a specified pressure. A positive or negative voltage is applied to the terminal 36a' of the electrode plate portion 36 and the terminal 36b' of the earth plate portion 36 is earthed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport belt and a belt transport apparatus and an image forming apparatus using the transport belt, and more particularly, to a technique for more stably carrying a sheet material on the transport belt.

[0002]

2. Description of the Related Art A transport belt for carrying and transporting a recording sheet is used, for example, in an ink jet recording apparatus which performs recording by discharging ink from a recording head onto a recording medium.

[0003] Among the ink jet recording apparatuses, a full line type apparatus using a plurality of stages (for each color) of a line type recording head in which a large number of ejection ports are arranged in the paper width direction can further increase the recording speed. is there.

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.
If the recording paper rises in the recording area of the transport belt, the recorded image may be disturbed or cause a jam or the like. Therefore, the recording paper needs to be closely attached to the transport belt so as not to float.

As a means therefor, there has been known a method in which a pair of conductive electrodes (adsorption force generating means) is provided on a conveyor belt carrying recording paper, and an electric charge is applied to generate an electrostatic force to adsorb the recording paper.

In such an ink jet recording apparatus, the recording paper fed by the paper feeder is fed to the upper surface of the transport belt by the above-mentioned electrostatic attraction means (conductive electrodes) provided on the transport belt in the recording area. Adsorbed on
It is held and conveyed while being recorded by the recording head.

FIG. 7 is a view for explaining a schematic configuration of a recording paper conveying apparatus 100 provided with a conveying belt 101.
7A is a top view and FIG. 7B is a side view.

The transport belt 101 is wound around three rollers, namely, a driving roller 102, a transport roller 103, and a pressure roller 104 for urging the transport belt 101 to have a predetermined tension. The drive roller 102 is a drive motor 105
Is transmitted via the belt 106 and rotates at a predetermined speed to move (rotate) the transport belt 101.

Reference numeral 107 denotes a power supply brush for applying a high voltage to the electrode 110 (collectively referred to as a plurality of electrodes).
Is a high voltage generator that applies a positive or negative high voltage to the power supply brush 107 (supplies power).

FIG. 8A is an enlarged view of a portion D1 in FIG. 7A, and shows a pattern (hatched portion) of an electrode disposed below the surface layer of the conveyor belt 101. FIG. FIG.
FIG. 2B is a side view of the power supply brush 107.

In FIG. 8A, a positive electrode 110A and a negative electrode 110B constituting an electrode 110 are connected to a conveyor belt 101.
Are arranged in a direction orthogonal to the transport direction of the camera.

The positive electrode 110A and the negative electrode 110B are set so that the potential difference is about several kilovolts.
Both the case where the negative electrode 110B is connected to the ground potential and the case where a negative voltage is applied are considered. This may be appropriately selected according to mounting conditions such as required functions and performance of the actual device.

The supply of the voltage from the power supply brush 107 to the electrode 110 is performed by the power-supplied portions 110A1 and 110B1 of the electrode 110 formed at the widthwise end of the transport belt 101.
Are opening windows 101a, 1a in the surface layer of the conveyor belt 101.
01b, and the power supply brush 1
Electric power is supplied to a portion of the electrode 110 where the brush 07 contacts the power-supplied portion.

The region where the electric power is supplied and the potential difference is generated is referred to as a suction region 112 (see FIG. 7A).

The recording paper, which enters from the upstream side of the conveyance belt 101 in the conveyance direction and is placed on the belt,
When it reaches the electrode 110, the electrode 110 provided on the conveyor belt 101
The recording paper (dielectric such as paper) is polarized by the electric field generated in the (adsorption force generating means), and as a result, attracting electrostatic force is generated, and the recording paper is attracted and carried on the transport belt 101.

[0016]

However, the suction force of the recording paper by the interdigital electrode pattern is not always uniformly distributed. That is, the spatial distribution of the density of the electric lines of force formed in the portion without the electrode, the end of the electrode, the center of the electrode, and the like changes, and the suction force is not constant.

It has been experimentally found that this adsorbing force is relatively strong in the fine portion of the electrode and relatively weak in the portion without the electrode. Therefore, it is necessary to pay attention to the positional relationship between the recording paper and the electrodes in terms of securing the attraction force of the recording paper to the fine portion, which is likely to be turned.

On the other hand, when the recording paper is conveyed by a belt,
If the suction force at the end of the recording paper is insufficient, the conveyance belt and the end of the recording paper may not adhere to each other due to the shape of the end of the recording paper, such as warpage.

In this case, there is also a phenomenon that some components or mechanisms located near the upper portion of the transport belt, such as an ink jet type print head, come into contact with the edge of the transported recording paper. I am concerned.

When the recording paper being transported comes into contact with an adjacent component or the like, the flatness of the recording paper is partially or completely lost at the contact portion, and the transport state is greatly affected. Effect.

Further, a recording head that has come into contact with recording paper may be severely hit by its printing ability.

On the other hand, it is generally known that the recording paper has a manufacturing direction called "grain" (grain: the longitudinal direction of the fiber of the paper). Gender also depends on this. That is, the rigidity in the gap direction (flexural rigidity) is usually superior to the rigidity in the direction perpendicular to the gap direction. Therefore, when the conventional electrode pattern is used for suction, the adsorbability is better when the gap and the electrode pattern are perpendicular to each other than when they are parallel.

However, the conventional electrode pattern is formed in a direction orthogonal to the recording paper transport direction as shown in FIG. 7, and the front end portion of the recording paper carried on the rotating transport belt. No special attention was paid to the positional relationship with the electrodes. For this reason, there is a problem with respect to the improvement of the recording paper transportability, that is, the suppression of the turning of the recording paper end.

The present invention solves the above-mentioned problems of the prior art, and an object of the present invention is to generate a stable suction force even at the end of a recording sheet.
It is also an object of the present invention to provide a transport belt provided with an attraction force generating means having an electrode pattern which is hardly affected by the direction of the paper gap, and to provide a belt transport apparatus and an image forming apparatus using the transport belt for transporting recording paper. It is in.

[0025]

According to another aspect of the present invention, there is provided a conveyor belt including a belt member having a supporting surface for supporting a sheet material, and a central portion of the belt member in a conveying width direction. A plurality of opposing electrodes arranged in the attraction force generating region, and an attraction force generating means having a power-supplied portion arranged at at least one end in the conveyance width direction of the belt member for supplying power to the opposing electrodes; Wherein the plurality of opposing electrodes are slanted with respect to a conveying width direction of the belt member. Characterized by having a region formed in

It is preferable that the plurality of counter electrodes are formed in a zigzag shape so as to cross a straight line in the transport width direction.

[0027] It is also preferable that a power-supplied portion for supplying power to the plurality of opposing electrodes is arranged at one end of the belt member in the conveying width direction so as to form a plurality of rows in the conveying width direction.

In the belt transport device, the transport belt described above, belt holding means for rotatably holding the transport belt, drive means for rotating the transport belt, and voltage generating means for the power-supplied portion And a power supply member for supplying a potential generated by the power supply.

In the image forming apparatus, it is preferable that the image forming apparatus includes an image forming unit that is disposed to face the transport belt of the belt transport device described above and that forms an image on a sheet material carried and transported by the transport belt. Features.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (Embodiment 1) As a first embodiment of the present invention, an ink ejection system as an image forming apparatus provided with a transport belt to which the present invention is applied along FIGS. A schematic configuration of a recording apparatus 1 having the above recording head and performing image formation will be described.

FIG. 1 is a cross-sectional view showing the overall configuration of the recording apparatus 1, and FIG. 2 is an explanatory view of the cross-sectional configuration of the paper feeding section 3 of the recording apparatus 1. The recording apparatus 1 has an automatic paper feeder. The printing apparatus includes a unit 2, a paper feeding unit 3 (belt conveying device), a paper discharging unit 4, and a recording head 7 (image forming unit). Therefore, these will be described in order as (A) paper feed unit, (B) paper feed unit, (C) recording head unit, and (D) paper discharge unit.

(A) Paper Feeding Unit The paper feeding unit 2 is a pressure plate 2 on which recording paper P as a sheet material is stacked.
1 and a feed rotating body 22 for feeding the recording paper P is attached to the base 20. The pressure plate 21 is the base 2
It is rotatable about a rotation shaft 21 a connected to the rotation shaft 0, and is urged by a pressure plate spring 24 to the feed rotation body 22.

A separation pad 25 made of a material having a large coefficient of friction, such as a leather, for preventing double feeding of the recording paper P is provided at a portion of the pressure plate 21 facing the feeding rotary body 22. Further, the base 20 covers a corner in one direction of the recording paper P as a sheet material, and a separation claw 26 for separating the recording paper P one by one, a contact between the pressure plate 21 and the feeding rotating body 22. A release cam (not shown) for releasing is provided.

In the above configuration, in the standby state, the release cam pushes the pressure plate 21 down to a predetermined position. Thereby, the contact between the pressure plate 21 and the feeding rotating body 22 is released.
Then, in this state, the driving force of the transport roller 32 is:
When the rotation is transmitted to the feed rotator 22 and the release cam by a gear or the like, the release cam separates from the pressure plate 21 and the pressure plate 21 rises, and the feed rotator 22 and the recording paper P come into contact with each other. With the rotation, the recording paper P is picked up and started to be fed, and is separated one by one by the separation claw 26 and sent to the paper feeding unit 3.

The feed rotator 22 rotates until the recording paper P is fed into the paper feed unit 3, and is again in a standby state where the contact between the recording paper P and the feed rotator 22 is released, and The driving force is turned off.

Reference numeral 90 denotes a feed rotating body for manual paper feed. The recording paper P set on the manual feed tray 91 is fed by a feeding rotating body 90 in accordance with a recording command signal from a computer, and is transported to a transport roller 32.

(B) Paper Feeding Unit The paper feeding unit 3 includes a transport belt 31 having a support surface for sucking and transporting the recording paper P and a PE sensor (PE: paper-edge sensor (not shown)). Etc.)).

The transport belt 31 is driven by a driving roller 34 and is wound around a transport roller 32 as a driven roller and a pressure roller 35.

The transport roller 32 and the drive roller 34 are rotatably mounted on the platen 30, and the pressure roller 35 has an arm 50 having one end swingably mounted on the platen 30.
The arm 50 is pressed by a spring 51 to apply tension to the transport belt 31. The platen 30 is located below the conveyor belt 31 and serves to hold the conveyor belt 31.

A pinch roller 33 driven by the conveyor belt 31 is provided at a position facing the conveyor roller 32. The pinch roller 33 is pressed against the conveyor belt 31 by a spring (not shown) to guide the recording paper P to the recording unit.

Further, an upper guide 27 and a lower guide 28 for guiding the recording paper P are provided at the entrance of the paper feeding section 3 to which the recording paper P is conveyed. The upper guide 27 is provided with a PE sensor lever 29 for transmitting the detection of the leading and trailing edges of the recording paper P to a PE sensor (not shown). Further, a recording head 7 as an image forming means for forming an image based on image information is provided downstream of the transport roller 32 in the recording paper transport direction.

In the above configuration, the recording paper P sent to the paper feeding unit 3 is guided by the upper guide 27 and the lower guide 28,
The sheet 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 paper P is detected by the PE sensor lever 29 to determine the printing position of the recording paper P. Further, the recording paper P is transported by the rotation of the transport belt 31 via the transport rollers 32 by a paper feed motor described later.

(C) Recording Head Unit In the recording head 7 of this embodiment, a plurality of nozzles as ejection ports are arranged in the direction (transport width direction) orthogonal to the transport direction of the recording paper P over the entire width of the recording area. In addition, a full line type ink jet recording head is used.

The recording head 7 is mounted on a head holder 7A, and 7K (black), 7C
(Cyan), 7M (magenta), and 7Y (yellow) in this order.

The recording head 7 is provided with an electrothermal energy converter for applying heat to the ink by a heater or the like. The heat causes the ink to boil, and the recording head changes due to a pressure change caused by growth or shrinkage of bubbles due to the film boiling. Ink is ejected from the nozzle No. 7 to form an image on the recording paper P.

The recording head 7 has one end rotatably fixed by a shaft 71 and a head holder 7A formed at the other end.
Is engaged with the rail 72, and the nozzle surface and the recording paper P
(Paper interval) is defined.

(D) Paper Discharge Unit The paper discharge unit 4 is composed of a paper discharge roller 41 and a spur 42, and the recording paper P on which an image is formed by the recording unit is sandwiched between the paper discharge roller 41 and the spur 42. Is conveyed to the discharge tray 43
Is discharged.

Next, the structure and operation of the suction conveyance of the recording paper P in the recording section and the structure of the suction force generating means are shown in FIGS.
This will be described with reference to (a) and (b).

First, the operation of the suction conveyance will be described with reference to FIGS. The transport belt 31 moves while adsorbing and holding the recording paper P.
It is made of a synthetic resin such as polyethylene or polycarbonate having a thickness of about 0.2 mm to 0.2 mm, and has an endless belt shape.

The conveying belt 31 is provided with a suction force generating means 36 described later.
By applying a voltage of V, an attraction force is generated in an attraction force generation area at the center of the transport belt 31 in the transport width direction in the recording section below the recording head 7. The power supply brush 52 is connected to a high-voltage power supply (not shown) that generates a predetermined high voltage.

As described above, 32, 34, and 35 are rollers that support the transport belt 31 and apply an appropriate tension, and the drive roller 34 is connected to the paper feed motor.

A paper pressing roller 40 as pressing means for pressing the recording paper P against the conveyor belt 31 is rotatably mounted on the support member 39, and the support member 39 is mounted around the rotation axis of the pinch roller 33 as a rotation center. Has been
The paper pressing roller 40 is urged toward the conveyor belt 31 by urging means (not shown).

As described above, the leading end of the recording paper P is pressed against the transport belt 31 by the paper pressing roller 40 in the area where the suction force generating means 36 can attract the recording paper P, so that the recording paper P is reliably attracted onto the belt. .

At a position facing the paper pressing roller 40, a driven roller 44 driven by the conveyance belt 31 is interposed.
0 so that the lower surface of the conveyor belt 31 and the upper surface of the platen 30 rub against each other when the belt 31 is pressed downward by the paper pressing roller 40, thereby reducing friction and frictional force. I have.

Reference numeral 38 denotes a cleaning roller pair, and the belt 3
1, which is capable of absorbing ink to remove dirt such as ink adhered to the belt 31 and has a small pore diameter (10 μm to 30 μm is preferable to prevent deterioration in durability. ) Formed by spikes of interconnected cells.

The transport belt 31 includes the cleaning roller pair 3
After the cleaning in step 8, the charge is removed by the gradual reduction brush 37 serving as the charge removing means.

Next, the suction force generating means 36 will be described with reference to FIG.
This will be described with reference to FIGS. 4 (a) and 4 (b) and FIGS. 4 (a), 4 (b) and 4 (c).

FIG. 3A is a view showing the pattern of the electrodes, FIG. 3B is a view of the entire conveyor belt 31, and FIG. 4A is a view from the direction of arrow A1 in FIG. FIG. 4B is a cross-sectional view as viewed from the direction of arrow B1 in FIG. 3, and FIG. 4C is a cross-sectional view illustrating a power supply unit that supplies power to the transport belt.

A suction force generating means 36 is provided inside the conveyor belt 31. In the figure, the suction force generating means 36 includes a plurality of electrode plates 36a and a ground plate 36b as a plurality of counter electrodes made of a conductive metal. As shown in FIG. 3, each tooth is independently formed in a comb-like pattern, and each convex portion is formed in each concave portion so that the directionality of the electrodes faces each other in the direction inclined in the belt conveyance width direction. A plurality of conveyor belts 31 are formed so as to enter.

Terminals 3, which are power-supplied parts with exposed patterns, are provided at both ends in the conveying width direction of the conveying belt 31.
6a 'and 36b' are electrodes 36a, 3
The power supply brushes 52 are provided with a distance longer than the width of each of the power supply brushes 6b.
Contact with a predetermined pressure, and the electrode plate 3
A positive or negative voltage is applied to the terminal 36a 'of the terminal 6a.
The terminal 36b 'of the ground plate 36b is grounded.

In this embodiment, when power is supplied from the high voltage generator to the power supply brush 52, a switching control means (not shown) is provided in the middle so that the power supply to the suction force generating means 36 can be controlled.

As shown in FIGS. 4 (a) and 4 (b), the transport belt 31 has an electrode plate 36a made of a conductive metal and an earth plate 36 in an attraction force generating region at the center of the belt.
The suction force generating means 36 constituted by b is provided so as to be protected by being sandwiched between the base layer 36C and the surface layer 36D.

The base layer 36C and the surface layer 36D are made of a synthetic resin such as polyethylene and polycarbonate.

When a voltage is applied to the electrode plate 36a, an electric force is generated in the direction of the arrow, and the lines of electric force shown in the figure are formed.

The potential difference between the electrode plate 36a and the ground plate 36b generates an attractive force at a position above the conveyor belt 31, and the voltage applied to the electrode plate 36a is applied to the recording surface of the recording paper P. (Surface potential) having the same polarity as the above.

The adsorbing force of the recording paper P is determined by the negative electrode plate 3
The portion without the conductive metal between 6a and the earth plate 36b is the lowest region.

Here, when a large amount of ink is ejected on the recording paper P, the recording paper P swells, and a wavy (cockling) occurs. In this case, the cockling of the recording paper P is changed to the electrode plate 36, which is the area having the lowest attraction force.
The floating of the recording paper P toward the recording head 7 can be suppressed to a minimum by causing the recording paper P to be generated at a portion where there is no conductive metal between the a and the ground plate 36b.

Next, the operation of suction conveyance of the recording paper P will be described with reference to FIGS. The recording paper P is fed to the transport belt 31 by a feed rotator 22 or the like that functions as sheet material feeding means on the upstream side of the transport belt 31.

In the transport belt 31, the recording paper P is nipped on the transport belt 31 by the transport roller 32 and the pinch roller 33, pressed against the transport belt 31 by the paper pressing roller 40, and conveyed by the suction force generating means 36. 31
The paper feed motor and the roller 3 are attracted to the recording section by being attracted to
4 is sent in the direction of arrow A2.

In FIG. 4C, the power supply brush 52 is supported by a support member 53 and is connected to a high-voltage power supply (not shown). A protection member 54 for protecting the power supply member including the power supply brush 52 and the support member 53 is attached to the platen 30 so as to surround the entire circumference of the power supply member.
The belt 31 is provided on the side of the belt 31 around the entire side end of the protection member 54.
A sealing member 55 made of a low-hardness elastomer provided in contact with the predetermined pressure is provided.

As described above, the protection member 54 and the sealing member 55
Thus, the power supply member is configured and installed so as to have a predetermined space around and to be isolated from the outside.

In the suction conveyance operation of the present embodiment, the conveyance belt 31 holding the recording paper P is used for recording the leading and trailing ends of the recording paper P in the suction area (image forming area) at the center in the conveyance width direction. Also, since there is no member traveling to the recording head 7 side, recording can be performed with the ejection nozzle at the end of the recording head 7 closer to the recording paper P, and a highly accurate recorded image can be obtained.

When a large amount of ink is ejected on the recording paper P, the recording paper P swells, and a wavy (cockling) occurs. Also in this case, the recording paper P is attracted to the conveyor belt 31 by the attraction force of the attraction force generating means 36, so that the recording paper P does not float to the head 7 side, so that the head 7 does not come into contact with the recording paper P and is stable. Can be recorded.

Further, even if the end of the recording paper P is wavy or curled due to changes in the environment such as temperature and humidity, the recording paper P is pressed against the transport belt 31 by the paper pressing roller 40. Since the sheet can be conveyed to the suction force generating section in a state in which waving and curling have been removed, stable suction can be performed in the recording section.

At this time, the leading end of the recording paper P adsorbed and carried on the conveyor belt 31 does not end up at an intermediate position between the electrodes, and the adsorbability of the leading end of the recording paper P is improved. It can be improved.

Further, it is possible to prevent the electrodes from being parallel to the direction of the gap of the recording paper P. Therefore, it is possible to improve the conveyance stability when the recording paper P is conveyed by the conveyance belt 31, and to improve the conveyance efficiency by reducing the conveyance failure, thereby reducing the recording paper discard rate.

Further, since it contributes to increase the design margin of the device configuration, it is possible to expect an economic effect of improving the assemblability and reducing the production cost.

Next, an encoder 80 capable of adjusting the feeding position of the recording paper P fed to the conveyor belt 31 will be described with reference to FIG.

In FIG. 3, marks 80A as encoders are provided on the surface of the conveyor belt 31 at a predetermined pitch. This pitch is, for example, 1/180, 1/360
And so on.

The mark 80A is detected by a sensor (not shown) provided above the conveyor belt 31, and a signal from the sensor is counted and integrated by a detecting means (not shown).

A count value for stopping the recording sheet P at a predetermined position is set in advance, and when the count value reaches the predetermined value, the driving of the transport belt 31 is stopped.

In the above description, the mark 80A may be white when the conveyor belt 31 is black, and black when the conveyor belt 31 is white. The material of the mark 80A is not particularly limited as long as it can surely adhere to the surface of the conveyor belt 31.

The mark 80A is not a mark attached to the surface of the conveyor belt 31, but may be a hole.

Further, in the present embodiment, the attraction force generating means 36, the power supply member, and the like are provided on the upper surface of the transport belt 31. A suction force may be generated on the upper surface of the feeding belt 31.

Similarly, each mark or sensor may be provided on the lower surface (back surface) of the conveyor belt 31 and read on the lower surface (back surface).

(Embodiment 2) Next, the configuration of a second embodiment according to the present invention will be described with reference to FIG. The second embodiment is substantially the same as the first embodiment, and the differences will be particularly described below.

FIG. 5A is a diagram showing the pattern shape of the electrodes 36a and 36b (a plurality of pairs exist) of the conveyor belt 31B of the second embodiment, and FIG.
FIG.

In FIG. 5, the patterns of the electrodes 36a and 36b are formed obliquely to the conveying width direction as in the first embodiment. The terminals 36 a ′ and 36 b ′ are disposed at one end in the conveying width direction of the conveying belt 31 </ b> B so as to be arranged in parallel in the conveying width direction. The power supply brush 52 is arranged in parallel with each terminal 36a ', 36b'.

The other configuration and operation are the same as those of the first embodiment, and the description is omitted.

(Embodiment 3) Next, the configuration of a third embodiment according to the present invention will be described with reference to FIG. First and second
In the embodiment, the pattern shape of the counter electrode is formed obliquely over almost the entire area (suction area) in the conveying width direction of the conveying belt, but may be provided with a partially oblique area.

FIG. 6A is a schematic view of a transport belt 31C provided with a counter electrode 36c (which may have a zigzag shape) patterned in a waveform, and an electrode having such a shape is also provided on the belt. The leading end of the recording paper P to be carried comes into contact with both the weak and strong parts of the suction force alternately, and the entire leading end of the recording paper P in the conveyance width direction is different from the prior art. Can be prevented from being carried on a weak portion of the recording paper P, and the conveyance of the recording paper P can be improved by preventing the end portion from being turned up.

FIG. 6 (b) is a schematic diagram showing a transfer belt 31D provided with a counter electrode 36d (which may be in a zigzag shape) which is patterned into a waveform and inclined with respect to the transfer width direction. It is. With such an electrode pattern, the same operation and effect as those of the transport belt 31C of FIG. 6A can be expected.

[0093]

According to the present invention described above, the opposing electrode formed in the attraction force generating area of the conveyor belt is formed obliquely to the conveyance width direction, so that the recording paper edge is formed. Is not located in a portion where the attraction force is weak, and the attraction force of the recording paper portion is secured almost in the same manner as other portions. In addition, since the direction of the gap of the paper is different from the direction of the counter electrode, the influence of the decrease in the attraction force due to the gap can be suppressed.

Accordingly, it is possible to stably convey the sheet material, and it is possible to suppress the occurrence of jamming or damage of the recording paper and to improve the operation stability of the apparatus.

By arranging the power-supplied portions at one end in the conveying width direction of the belt member in a plurality of rows, the power-supplied portions can be put together and a simpler configuration can be realized. .

[Brief description of the drawings]

FIG. 1 is an explanatory cross-sectional configuration diagram illustrating an overall configuration of an image forming apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory cross-sectional configuration diagram of a paper feeding unit according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram of a configuration of a transport belt according to the first embodiment of the present invention.

4A is a cross-sectional view as viewed from the direction of arrow A1 in FIG. 3, FIG. 4B is a cross-sectional view as viewed from the direction of arrow B1 in FIG. 3, and FIG. It is the elements on larger scale of a feed part.

FIG. 5 is a configuration explanatory view of a transport belt according to a second embodiment of the present invention.

FIG. 6 is a configuration explanatory view of a transport belt according to a third embodiment of the present invention.

FIG. 7 is a configuration explanatory view of a conventional transport belt.

FIG. 8 is a diagram illustrating a configuration of a conventional transport belt.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Recording device 2 Paper feed part 3 Paper feed part 4 Paper discharge part 7 Recording head 20 Base 21 Pressure plate 21a Rotating shaft 22, 90 Feed rotation body 24 Pressure plate spring 25 Separation pad 26 Separation claw 27 Upper guide 28 Lower guide 29 PE sensor Lever 30 Platen 31 Conveyor belt 32 Conveyor roller 33 Pinch roller 34 Drive roller 35 Pressure roller 36 Attraction force generating means 37 Static elimination brush 38 Cleaning roller pair 39 Support member 40 Paper press roller 41 Discharge roller 42 Spur 43 Discharge tray 44 Follower Roller 50 Arm 51 Spring 52 Power supply brush 53 Support member 54 Protective member 55 Sealing member 71 Axis 72 Rail 91 Bypass tray P Recording paper

Claims (5)

[Claims] 1. A belt member having a supporting surface for supporting a sheet material, a plurality of opposed electrodes disposed in an attraction force generating region at a central portion in a conveying width direction of the belt member, and power supply to the opposed electrodes And a power-receiving portion disposed at at least one end of the belt member in the conveying width direction of the belt member. A transport belt capable of being transported by suction, wherein the plurality of opposed electrodes have a region formed obliquely to a transport width direction of the belt member. 2. The transport belt according to claim 1, wherein the plurality of opposing electrodes are formed in a zigzag shape so as to cross a straight line in the transport width direction. 3. A power-supplied portion for supplying power to the plurality of counter electrodes is arranged at one end of the belt member in the conveying width direction so as to form a plurality of rows in the conveying width direction. Item 3. The transport belt according to item 1 or 2. 4. The transport belt according to claim 1, a belt holding unit that rotatably holds the transport belt, a driving unit that rotates the transport belt, and the power supply unit. And a power supply member for supplying a potential generated by the voltage generating means to the belt conveying device. 5. A belt conveying device according to claim 4, further comprising an image forming means arranged to face the conveying belt and forming an image on a sheet material carried and conveyed by the conveying belt. Image forming device.