JP2000198566A - Sheet sucking and feeding device and recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the contamination and abrasion of a feeding means by providing a feeding part moving means for moving the feeding means to be contacted with or separated from a part to be fed, and a control means for movement of feeding part for moving the feeding means by the feeding part moving means on the basis of the information on the operation mode of the device. SOLUTION: The feeding brushes 4, 5 as the feeding means movably mounted on the upper parts of the members to be fed 2a, 3a are contacted with the members to be fed 2a, 3a to supply the electric power thereto. When the feeding solenoids 9a, 9b are switched ON, a connection part 13 and the supporting members 6, 7 are lowered, as a result, the feeding brushes 4, 5 are contacted with the members to be fed 2a, 3a and the electric power is supplied thereto. When the feeding solenoids 9a, 9b are switched OFF, the connection part 13 and the supporting members 6, 7 are upwardly, the feeding brushes 4, 5 are separated from the members to be fed 2a, 3a, and the power supply is cut. The feeding solenoids 9a, 9b are controlled by a control part as a movement of feeding part control means on the basis of the information on the operation mode of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet sucking and conveying apparatus for electrostatically sucking and conveying a sheet, and a recording apparatus having the same.

[0002]

2. Description of the Related Art Conventionally, there has been an ink jet recording apparatus using a full-line type recording head to enable high-speed and high-quality recording. The electrodes are provided in a comb-like shape, an electric charge is applied to the comb-like electrodes to generate an electrostatic force, and the recording sheet is attracted and conveyed.

FIG. 9A is a cross-sectional view of a main portion showing a configuration of a power-receiving portion of a comb-like electrode embedded in a transport belt of a conventional sheet suction transport device. Inside the conveyor belt 51, a comb-shaped electrode 52 made of a conductive metal is built in. Under the comb-shaped electrode 52, a base layer 51a of the conveyor belt 51 is formed, and above the comb-shaped electrode 52. Is formed with a surface layer 51b.

A power-supplied member 54 that can contact a power supply brush 53 for supplying power to the comb-shaped electrode 52 is electrically connected to the comb-shaped electrode 52. Is a flat surface flush with the upper surface of the surface layer 51b of the transport belt 51.

[0005]

However, in the above-described conventional example, the upper surface 54a of the power-supplied member 54 is
Since the power supply brush 53 is in contact with the surface of the conveyor belt 51 because the power supply brush 53 is also flush with the upper surface of the surface layer 51b, there is a problem that the power supply brush 53 is stained and the power supply brush 53 is quickly worn. Was.

Further, since the power supply brush 53 has been in contact with the power-supplied member 54 for a long time, the power-supply brush 53 changes over time as shown in FIG.
As shown in (1), there is a possibility that the leading end of the power supply brush 53 is worn and a contact failure occurs between the power supply brush 53 and the power-supplied member 54, thereby causing a problem in power supply.

Further, when cleaning the transport belt 51 by a cleaning means in order to remove the dirt or the like of the transport belt 51, it is easier to clean the belt by retracting the power supply brush 53 from the power-supplied member 54. There was also a request.

[0008] The present invention is to solve the above problems,
It is an object of the present invention to provide a sheet suction / conveyance apparatus capable of reducing contamination and abrasion of a power supply unit and facilitating cleaning of a conveyance belt, and a recording apparatus including the same.

[0009]

A typical configuration according to the present invention for achieving the above object is to contact a power-supplied portion which is electrically connected to an electrode provided on a conveyance belt for conveying a sheet. A sheet feeding and conveying device that has a feeding unit capable of feeding a sheet and feeds the sheet electrostatically and conveys the sheet to the surface of the conveyance belt, wherein the feeding unit moves the feeding unit to approach and separate from the power receiving unit A sheet suction / conveying apparatus comprising: a moving unit; and a power supply unit movement control unit that moves the power supply unit by the power supply unit moving unit based on operation mode information of the apparatus.

According to the above configuration, the power supply unit movement control means moves the power supply unit by the power supply unit movement unit based on the operation mode information of the apparatus so that the power supply unit moves toward and away from the power supply unit. Since the power supply means does not come into contact with the surface of the conveyor belt when the power supply means is separated from the belt, dirt and wear of the power supply means can be reduced.

That is, by separating the power supply means from the power-supplied portion based on the operation mode information of the apparatus, the power supply means does not contact the power-supplied portion for a long time. Of the power supply means and the power-supplied portion, thereby preventing poor contact between the power-supplying means and the power-supplied portion, thereby enabling good power supply.

Also, the power supply means is used when the dirt on the conveyor belt is detected by the dirt detecting means for detecting the dirt on the conveyor belt, or when the conveyor belt is cleaned by the cleaning means to eliminate the dirt on the conveyor belt. Can be easily retracted from the power-supplied portion, and the dirt detection and cleaning can be easily performed.

A surface layer in which the conveyor belt contacts the sheet; a pair of alternately arranged comb-like electrode layers laminated inside the surface layer and applied with different potentials; A base layer for supporting an electrode layer, wherein the pair of comb-shaped electrode layers are covered over the entire circumference by the surface layer and the base layer, and the pair of comb-shaped electrodes are electrically connected to each other. The power-supplied portions connected to the power-supply portion are arranged at both end portions in a direction perpendicular to the rotation direction of the transport belt in the rotational direction of the transport belt, and provided so as to be exposed from the surface layer of the transport belt. It is preferable that the power supply means movably provided at the upper part of the unit be configured so as to be able to contact and supply power to the power supplied unit.

The power supply unit moving means may move the power supply means in the vertical direction or rotate the power supply means about a rotation axis so that the power supply means comes into contact with or separates from the power supplied part. It is preferable to configure.

It is preferable that the operation mode is a mode in which a sheet is not conveyed.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention applied to an ink jet recording apparatus as an example of a sheet suction / conveyance apparatus and a recording apparatus having the same. FIG. 1 is an explanatory plan view showing the configuration of a sheet suction and conveyance device according to the present invention, and FIG. 2 is a cross-sectional view of a main part showing the configuration of a power supply unit and a power-supplied unit of the first embodiment of the sheet suction and conveyance device according to the present invention. FIG. 3 is an explanatory cross-sectional view showing a configuration of a recording apparatus provided with the sheet suction / conveyance device according to the present invention. FIG. FIG. 5 is a diagram showing a state of an electrostatic attraction force generated between a pair of alternately arranged comb-teeth-shaped electrodes to which different potentials are applied. FIG. 6 is a flowchart of a control system according to the first embodiment. FIG. 7 is a cross-sectional view illustrating a main part of a sheet feeding and conveying device according to a second embodiment of the present invention. It is a flowchart of a control system.

First, a first embodiment of a sheet suction / conveyance apparatus according to the present invention and a recording apparatus having the same will be described with reference to FIGS. In FIG. 1, reference numeral 1 denotes an endless transport belt for electrostatically attracting and transporting a recording sheet P made of a dielectric material such as paper or a synthetic resin. It is made of body material.

Inside the conveyor belt 1, a pair of alternately arranged comb-like electrode layers 2, 3 made of a conductive material to which different potentials are applied, and these comb-like electrode layers 2, 3 are provided. Power-supplied members 2a and 3a that are electrically connected and disposed at both ends of the conveyor belt 1 are built in.

The comb-teeth-shaped electrode layers 2 and 3 are arranged so as to face each other in parallel to a direction perpendicular to the rotation direction of the conveyor belt 1, and each of the comb teeth on both sides in a direction orthogonal to the rotation direction of the conveyor belt 1. Respectively electrically connected to the electrode layers 2 and 3;
In the direction of rotation of the conveyor belt 1, the comb-like electrode layers 2, 3
Power-supplied members 2a and 3a having a dimension longer than the width of are provided.

As shown in FIG. 2, the base of the conveyor belt 1 supporting the pair of comb-like electrode layers 2 and 3 is provided below the comb-like electrode layers 2 and 3 embedded in the conveyor belt 1. Layer 1a
Is formed, and a surface layer 1b in contact with the recording sheet P is formed on the comb-like electrode layers 2 and 3.

The comb tooth-shaped electrode layers 2 and 3 laminated inside the surface layer 1b are covered over the entire circumference by the surface layer 1b and the base layer 1a. Power-supplied members 2a and 3a that are electrically connected are arranged in both ends of a direction perpendicular to the rotation direction of the conveyor belt 1 in the rotation direction of the conveyor belt 1, and are exposed from the surface layer 1b of the conveyor belt 1. The power supply brushes 4 and 5 movably provided above the power-supplied members 2a and 3a are provided so as to contact the power-supplied members 2a and 3a to supply power. .

Above the power-supplied members 2a and 3a, conductive power-supply brushes 4 and 5 that can contact the power-supplied members 2a and 3a at predetermined pressures are supported by support members 6 and 7, respectively. The supporting members 6 and 7 are connected to the power supply solenoids 9a and 9b, which serve as power supply unit moving means, by a joint 13.

The power supply solenoids 9a and 9b are
N / OFF causes the joint 13 between the power supply solenoids 9a, 9b and the support members 6, 7 to move up and down by about 2 mm. That is, when the power supply solenoids 9a and 9b are turned ON,
As a result, the power supply brushes 4 and 5 are brought into contact with the power-supplied members 2a and 3a to be energized.

When the power supply solenoids 9a, 9b are turned off, the joint 13 and the support members 6, 7 rise, and as a result,
The power supply brushes 4, 5 are separated from the power-supplied members 2a, 3a, and the power supply is interrupted.

The power supply solenoids 9a and 9b are controlled by a control unit 10 serving as power supply unit movement control means based on operation mode information of the apparatus.

The comb-teeth-shaped electrode layers 2 and 3 are configured by a high-voltage generator (not shown) to supply a high voltage having a potential difference of about several kilovolts between the positive electrode and the negative electrode. However, in the present embodiment, the comb-like electrode layer 2 is connected to the positive electrode, and the negative electrode of the comb-like electrode layer 3 is connected to the ground potential.

When the power supply solenoids 9a and 9b are driven to bring the power supply brushes 4 and 5 into contact with the power supply members 2a and 3a, the power supply brushes 4 and 5 and the power supply member 2a , 3a, a positive voltage is applied to the comb-like electrode layer 2, and the comb-like electrode layer 3 is connected to the ground potential.

The comb-toothed electrode layers 2 and 3 are provided so as to be protected by being sandwiched between a base layer 1a made of a dielectric material and a surface layer 1b, and the base layer 1a has a volume resistivity of 1.
0 ¹⁵ to 10 ¹⁷ Ωcm, the surface layer 1b has a volume resistivity of 10 ¹⁰ to 1
0 ¹⁴ Both polyethylene [Omega] cm, and a synthetic resin such as polycarbonate.

The power-supplied members 2a and 3a are made of a conductive synthetic resin containing carbon having a volume resistivity of 10 ^-4 to 10 ⁵ Ωcm. The surface layer 1b and the power-supplied member 2
a, 3a surfaces are subjected to surface treatment such as fluororesin processing,
Since the water repellency is in a good state, ink droplets ejected from the recording heads 8Y, 8M, 8C, and 8K, which are recording means, are less likely to remain on the power-supplied members 2a and 3a, thereby achieving good power supply. . The power supply brushes 4 and 5 are preferably made of a conductive material having a volume resistivity of 10 ^-4 to 10 ^-5 Ωcm.

When a voltage is applied to the comb-like electrode layer 2, an electric force is generated between the comb-like electrode layers 2 and 3 to form electric force lines as shown by arrows in FIG. . Then, an electrostatic attraction force is generated above the transport belt 1 by the potential difference between the comb-toothed electrode layers 2 and 3, and the recording sheet P is attracted to the transport belt 1 and transported.

In this embodiment, the volume resistivity [Ωcm] of the base layer 1a is set to be larger than that of the surface layer 1b, so that the lines of electric force generated between the comb-teeth-shaped electrode layers 2 and 3 are conveyed. Since the upper surface of the belt 1 is larger, the suction force of the recording sheet P can be increased.

The power supply brushes 4, 5 drive the power supply solenoids 9a, 9b except when power supply is necessary during the recording operation, and are retracted to a position spaced apart from the power-supplied members 2a, 3a by about 2 mm. The belt 1 is set so as not to contact the surface. As a result, the power supply brushes 4 and 5 do not come into contact with the conveyor belt 1, so that dirt and wear of the power supply brushes 4 and 5 can be reduced, and the life of the power supply brushes 4 and 5 can be extended.

Next, the configuration of an ink jet recording apparatus provided with the above-described sheet suction and conveyance device will be described with reference to FIG. In FIG. 3, a sheet feeding unit 22 is rotatable about a rotation shaft 21a on which a pressure plate 21 on which a recording sheet P is stacked is connected to a base 23, and feeds a recording sheet P by a pressure plate spring 24. It is urged to.

The pressure plate 21 is provided with a separation pad 25 having a large coefficient of friction for preventing double feeding of the recording sheet P, and a separation claw 26 is arranged facing an end of the pressure plate 21. Further, the contact between the pressure plate 21 and the feed rotary member 22 is released by a release cam (not shown).

In the standby state, the release cam pushes down the pressure plate 21, whereby the contact between the pressure plate 21 and the feed rotary body 22 is released. Then, in this state, when the driving force of the transport roller 27 is transmitted to the feed rotator 22 and the release cam by a gear or the like (not shown), the release cam separates from the pressure plate 21 and the pressure plate 21 rises, and the feed rotator The recording sheet P is brought into contact with the recording sheet P, and the recording sheet P is picked up by the rotation of the feeding rotating body 22 to start feeding. The feed rotator 22 rotates until the recording sheet P is sent to the sheet transport unit.
Reference numeral 28 denotes a feeding rotating body for manual feeding, which feeds the recording sheet P placed on the manual feeding tray 29 to the sheet conveying unit at the time of manual feeding.

The sheet transport section has the above-described transport belt 1 for electrostatically attracting and transporting the recording sheet P, and a PE (paper edge) sensor (not shown). The transport belt 1 is driven by a drive roller 30, and a transport roller 27 which is a driven roller.
And a pressure roller 31.

A pinch roller 33 that rotates following the conveyance belt 1 is in contact with a position facing the conveyance roller 27, and a recording head (yellow) serving as a recording unit is provided downstream of the conveyance roller 27 in the conveyance direction of the recording sheet P. ) 8Y, (Magenta) 8M,
(Cyan) 8C and (Black) 8K are arranged.

The resolution of the recording heads 8Y, 8M, 8C and 8K is as follows.
This is a line type ink jet recording head in which a plurality of nozzles are arranged in a direction orthogonal to the conveying direction of the recording sheet P at 600 DPI.

The recording heads 8Y, 8M, 8C, 8K can apply heat to the ink by a heater or the like, and the heat causes the ink to boil, and the growth or shrinkage of bubbles due to the film boiling. The ink is ejected from the nozzle by the pressure change caused by the pressure, and an image is formed on the recording sheet P.

The sheet discharge section is constituted by a discharge roller 34 and a spur 35, and the recording sheet P on which an image has been formed is conveyed while being nipped between the discharge roller 34 and the spur 35 and discharged to a discharge tray 36.

In FIG. 3, reference numeral 32 denotes a pair of cleaning rollers serving as cleaning means for cleaning the transport belt 1. The cleaning roller pair 32 is normally separated, and during cleaning, the cleaning roller pair 32 abuts on the transport belt 1 by the cleaning solenoid 32a shown in FIG.

Next, the configuration of the control system will be described with reference to FIG. Reference numeral 10 denotes a control unit serving as a power supply unit movement control unit,
CPU (Central Information Processing Unit) 10a that operates according to the control program, ROM (Read Only Memory) 10b that stores the program, working memory, and conveyor belt 1
And a gate array 10d. The RAM 10c is a memory for storing dirt detection data.

The gate array 10d, together with the CPU 10a, supplies signals to the recording heads 8Y, 8M, 8C, 8K, control signals to the motor 12 for transporting the recording sheet P, and power to the comb-like electrode layers 2 and 3 of the transport belt 1. An LSI for controlling a control signal to a high-voltage generator (not shown) and a signal from a belt contamination detection sensor 11
(Semiconductor integrated circuit).

The control unit 10 includes a cleaning solenoid for moving the cleaning roller pair 32 toward and away from the conveyor belt 1.
32a, a motor 1 serving as a drive source for rotating the conveyor belt 1
2. The recording heads 8Y, 8M, 8C, 8K for yellow, magenta, cyan, and black, the conveyor belt 1, the sensor 11 for detecting belt dirt, and the support members 6, 7 for the power supply brushes 4, 5 are raised and lowered to supply the power supply brushes. Power supply solenoids 9a and 9b for connecting and disconnecting the power supply members 4 and 5 to and from the power receiving members 2a and 3a are connected.

The recording heads 8Y, 8M, 8C, and 8K have fine liquid discharge ports (orifices), liquid paths, an energy operation section provided in a part of the liquid paths, and a liquid that acts on the liquid in the operation section. An energy generating means for generating droplet forming energy is provided.

As an energy generating means for generating such energy, a recording method using an electromechanical transducer such as a piezo element or the like, an electromagnetic wave such as a laser is irradiated to generate heat, and droplets are discharged by the action of the generated heat. There are a recording method using an energy generating means, and a recording method using an energy generating means for discharging a liquid by heating a liquid by an electrothermal converter such as a heating element having a heating resistor.

Among them, a recording head used in an ink jet recording method for discharging a liquid by thermal energy has a high density of liquid discharge ports (orifices) for discharging a recording liquid droplet to form a discharge liquid droplet. Since they can be arranged, high-resolution recording can be performed.

Among them, a recording head using an electrothermal transducer as an energy generating means can be easily made compact, and has recently achieved a remarkable advance in technology in the semiconductor field and a remarkable improvement in reliability. This is advantageous because the advantages can be fully utilized, high-density mounting is easy, and the manufacturing cost is low.

In the above-described embodiment, the ink jet recording system is used as the recording means. However, a current is applied to the electrothermal transducer according to a recording signal, and a film generated in the ink by the thermal energy applied by the electrothermal transducer. It is further preferable that the recording is performed by discharging the ink from the discharge port by the growth and shrinkage of the bubble generated in the ink by utilizing the boiling.

Regarding the typical configuration and principle, it is preferable to use the basic principle disclosed in, for example, US Pat. Nos. 4,723,129 and 4,740,796.

Further, as the form of the above-described ink jet recording apparatus, in addition to the one used as an image output terminal of an information processing apparatus such as a computer, a form of a copying apparatus combined with a reader or the like, and a form of a facsimile apparatus having a transmission / reception function May be used. Further, the recording heads 8Y, 8M, 8C, and 8K do not need to be limited to the line recording method, and may use a so-called serial recording method.

Next, a control flow of the recording apparatus will be described with reference to FIG. In FIG. 6, first, step S
At 1, the operation mode of the apparatus is checked. If the operation mode is a mode in which the recording sheet P is not conveyed and the operation of cleaning the conveyance belt 1 is performed,
Proceed to step S2.

In step S2, the control unit 10 turns on the power supply solenoids 9a and 9b, moves the power supply brushes 4 and 5 upward, and retracts them from the conveyor belt 1. Then, in step S3, the control unit 10 controls the cleaning solenoid 32.
The cleaning roller pair 32 is brought into contact with the conveyor belt 1 by operating the a, and the conveyor belt 1 is rotated to clean the conveyor belt 1.

When the cleaning operation is completed, the control unit 10
Actuates the cleaning solenoid 32a to detach the cleaning roller pair 32 from the conveyor belt 1;
Then, the control unit 10 turns off the power supply solenoids 9a and 9b, moves the power supply brushes 4 and 5 downward to contact the conveyor belt 1, and the operation is completed.

On the other hand, in step S1, if the operation mode of the apparatus is a recording operation for conveying the recording sheet P,
In step S5, the feeding operation of the recording sheet P and step S5
At 6, the recording sheet P is conveyed while performing the recording operation by the recording heads 8Y, 8M, 8C, 8K, and at step S7, the recording sheet P on which the image is recorded is discharged.

During the period from the feeding operation to the discharging operation of the recording sheet P in steps S5 to S7, the power supply brushes 4 and 5 come into contact with the power-supplied members 2a and 3a of the conveyor belt 1 to form the comb-toothed electrode layers 2 and 3. Powered.

According to the above configuration, the control unit 10 serving as the power supply unit movement control means uses the power supply solenoids 9a and 9b serving as the power supply unit movement means based on the operation mode information of the apparatus, so that the power supply brushes 4 and 5 serving as the power supply means. To move the power-supplied member 2
When the power supply brushes 4 and 5 are separated from the power-supplied members 2a and 3a in order to contact and separate from the power supply brushes 4a and 3a, the power supply brushes 4 and 5 do not come into contact with the surface of the conveyor belt 1, so that the power supply brushes 4 and 5 become dirty. And wear can be reduced.

That is, the power supply brushes 4, 5 are separated from the power-supplied members 2a, 3a based on the operation mode information of the apparatus, so that the power-supply brushes 4, 5 are extended over a long period of time.
a, 3a, so that the power supply brushes 4, 5 and the power-supplied members 2a, 3a or the surface layer 1b of the conveyor belt 1 can be prevented from being worn and the life can be extended,
It is possible to prevent poor contact between the power supply brushes 4 and 5 and the power-supplied members 2a and 3a, thereby enabling a good power supply.

Further, also in the case where the conveying belt 1 is cleaned by a cleaning roller pair 32 serving as a cleaning means in order to remove dirt and the like of the conveying belt 1, the power supply brushes 4 and 5 are used to connect the power-supplied members 2a, 3a and 3a. The cleaning can be easily performed by retracting from the conveyor belt 1.

Next, a second embodiment of the sheet suction and conveyance device according to the present invention will be described with reference to FIG. The same components as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

In this embodiment, as shown in FIG. 7, the support members 6, 7 of the power supply brushes 4, 5 are rotated about a rotation shaft 41 arranged in parallel with the rotation direction of the conveyor belt 1, to thereby supply the power supply brushes. 4, 5 are configured to be brought into contact with and separated from the power-supplied members 2a, 3a.

The supporting members 6 and 7 are provided with a power supply solenoid 9.
a and 9b are connected by a joint 42. When the power supply solenoids 9a and 9b are turned on, the joint 42 is
7, the support members 6, 7 rotate clockwise in FIG. 7 around the rotation shaft 41, and the power supply brushes 4, 5 come into contact with the power-supplied members 2a, 3a to energize. I do.

The power supply solenoids 9a and 9b are OF
7, the joint 42 moves to the left in FIG. 7, and as a result, the support members 6 and 7 rotate counterclockwise in FIG. Power supply members 2a, 3
a, and cut off the current supply. At this time, the rotation angle θ of the power supply brushes 4 and 5 is set to an angle away from the conveyor belt 1 by about 2 mm.

In the present embodiment, the space for movement is smaller and the structure is simpler than in the first embodiment in which the power supply brushes 4 and 5 are moved in the vertical direction. The degree improves. Other configurations are the same as those of the first embodiment, and the same effects can be obtained.

In the above embodiment, the rotation direction of the power supply brushes 4, 5 is set in the counterclockwise direction in FIG. 7 around the rotation shaft 41 so that the power supply brushes 4, 5 face the outside of the conveyor belt 1. Was configured to evacuate, but as another configuration,
The rotation direction of the power supply brushes 4, 5 may be set to the clockwise direction in FIG. 7 about the rotation shaft 41 so that the power supply brushes 4, 5 are retracted toward the inside of the conveyor belt 1. .

Next, a third embodiment of the sheet suction / conveyance apparatus according to the present invention will be described with reference to FIG. In addition, components configured in the same manner as the above-described embodiments are denoted by the same reference numerals, and description thereof is omitted.

FIG. 8 shows a control flow of the third embodiment.
In FIG. 8, first, in step S11, the operation mode of the apparatus is checked. If the operation mode is the mode in which the recording sheet P is not conveyed and the operation is to detect the contamination of the conveyance belt 1, the process proceeds to step S12.

In step S12, the control unit 10 turns on the power supply solenoids 9a and 9b, moves the power supply brushes 4 and 5 upward, and retracts them from the conveyor belt 1. Then, in step S13, a dirt detection operation is performed by the belt dirt detection sensor 11, and the dirt detection information is transmitted to the control unit 10.

The belt contamination detecting sensor 11 is an optical sensor of a serial type, and reciprocally scans the surface of the conveyor belt 1 to detect the contamination state on the surface. Conveyor belt 1
Is conveyed by the width read by the belt contamination detecting sensor 11. Then, the reading of the belt contamination detecting sensor 11 is repeated, and the conveyor belt 1 is caused to make one revolution to scan the entire surface of the conveyor belt 1.

The data read by the belt contamination detecting sensor 11 is temporarily stored in a memory, and the data is checked sequentially. If the value of the data is larger than the predetermined threshold value, it is determined that there is dirt.

When the dirt detecting operation is completed, step S14 is performed.
Then, the control unit 10 turns off the power supply solenoids 9a and 9b, moves the power supply brushes 4 and 5 downward to contact the conveyor belt 1, and the operation is completed.

On the other hand, in step S11, if the operation mode of the apparatus is a recording operation for conveying the recording sheet P,
In step S15, the feeding operation of the recording sheet P and step S15
At 16, the recording sheet P is conveyed while performing the recording operation by the recording heads 8Y, 8M, 8C, 8K, and at step S17, the recording sheet P on which the image is recorded is discharged.

During the feeding operation and the discharging operation of the recording sheet P in steps S15 to S17, the power supply brushes 4, 5 contact the power-supplied members 2a, 3a of the transport belt 1 to form the comb-shaped electrode layers 2, 3. Powered. In the present embodiment, the power supply brushes 4, 5 are retracted from the power-supplied members 2 a, 3 a even when the contamination of the conveyor belt 1 is detected by the belt-contamination detection sensor 11 serving as a contamination detection unit for detecting the contamination of the conveyor belt 1. As a result, the dirt can be easily detected. Other configurations are configured in the same manner as the above embodiments, and similar effects can be obtained.

In each of the above embodiments, the power supply brushes 4, 5
Has shown an example in which the distance from the conveyor belt 1 is set to 2 mm, but another distance may be set as appropriate as needed.

The mode for retracting the power supply brushes 4 and 5 from the conveyor belt 1 is the cleaning mode for the conveyor belt 1 in the first embodiment, and the dirt detection mode for the conveyor belt 1 in the third embodiment. The mode is not limited to these modes, and the power supply brushes 4 and 5 may be appropriately moved to the power-supplied members 2a and 3a or the transport in various modes in which the transport belt 1 is operated without supplying power to the comb-like electrode layers 2 and 3. It may be configured to be retracted from the belt 1.

The resolution of the recording heads 8Y, 8M, 8C and 8K is not limited to 600 DPI, but may be other resolutions.

[0077]

Since the present invention has the above-described configuration and operation, the power supply unit movement control means moves the power supply means by the power supply unit movement means based on the operation mode information of the apparatus, and moves the power supply unit to the power supplied unit. Since the power supply means is not in contact with the surface of the conveyor belt in a state where the power supply means is separated from the power-supplied portion, the dirt and abrasion of the power supply means can be reduced.

That is, by separating the power supply means from the power-supplied portion based on the operation mode information of the apparatus, the power supply means does not contact the power-supplied portion for a long time. Of the power supply means and the power-supplied portion, thereby preventing poor contact between the power-supplying means and the power-supplied portion, thereby enabling good power supply.

The power supply means is also used when the dirt detecting means for detecting the dirt on the transport belt detects dirt on the transport belt or when the transport belt is cleaned by the cleaning means to remove dirt on the transport belt. Can be easily retracted from the power-supplied portion, and the dirt detection and cleaning can be easily performed.

The power supply unit moving means moves the power supply means in the vertical direction or rotates the power supply means about a rotation axis so that the power supply means comes into contact with or separates from the power supplied part. It is preferable if it is constituted, especially when the power supply means is rotated around the rotation axis and moved, a space for the movement is small and the structure is simple, which is preferable, and the degree of freedom in design is improved.

[Brief description of the drawings]

FIG. 1 is an explanatory plan view showing a configuration of a sheet suction and conveyance device according to the present invention.

FIG. 2 is an explanatory cross-sectional view of a main part showing a configuration of a power supply unit and a power-supplied unit of the first embodiment of the sheet suction conveyance device according to the present invention.

FIG. 3 is an explanatory cross-sectional view illustrating a configuration of a recording apparatus including a sheet suction and conveyance device according to the present invention.

FIG. 4 is a block diagram illustrating a configuration of a control unit of a recording apparatus including the sheet suction conveyance device according to the present invention.

FIG. 5 is a diagram showing a state of an electrostatic attraction force generated between a pair of alternately arranged comb-shaped electrodes to which different potentials are applied.

FIG. 6 is a flowchart of a control system according to the first embodiment.

FIG. 7 is a cross-sectional view illustrating a main part of a sheet feeding and conveying device according to a second embodiment of the present invention, illustrating a configuration of a power supply unit and a power supply unit;

FIG. 8 is a flowchart of a control system of a sheet suction conveyance device according to a third embodiment of the present invention.

FIG. 9 is a diagram illustrating a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Conveyor belt, 1a ... Base layer, 1b ... Surface layer, 2, 3
... Comb-shaped electrode layers, 2a, 3a. Power-supplied members, 4, 5. Control unit, 10
a: CPU, 10b: ROM, 10c: RAM, 10d: gate array, 11: belt dirt detection sensor, 12: motor,
Reference numeral 13 denotes a joint, 21 denotes a pressure plate, 21a denotes a rotating shaft, 22 denotes a feeding rotary member, 23 denotes a base, 24 denotes a pressure plate spring, 25 denotes a separation pad, and 26 denotes a separation pad.
Separating claw, 27: conveying roller, 28: feeding rotating body, 29: manual feed tray, 30: driving roller, 31: pressure roller, 32: cleaning roller pair, 32a: cleaning solenoid, 33
... pinch roller, 34 ... discharge roller, 35 ... spur, 36 ... discharge tray, 41 ... rotating shaft, 42 ... joint, P ... recording sheet

Claims (7)

[Claims] 1. A power supply means for supplying power by contacting a power-supplied portion electrically connected to an electrode provided on a transport belt for transporting a sheet, and electrostatically adsorbing the sheet on the surface of the transport belt. A feeding unit moving unit that moves the feeding unit to move toward and away from the power-receiving unit; and a feeding unit that is driven by the feeding unit moving unit based on operation mode information of the device. And a power supply unit movement control means for moving the sheet feeding device. 2. The conveyor belt according to claim 1, wherein the conveyor belt has a surface layer in contact with the sheet, a pair of alternately arranged comb-like electrode layers laminated inside the surface layer and to which different potentials are applied, and the pair of comb-like electrode layers. A base layer supporting an electrode layer, wherein the pair of comb-shaped electrode layers are covered over the entire circumference by the surface layer and the base layer, and the pair of comb-shaped electrodes are electrically connected to each other. The power-supplied portions connected to the power-supply portion are arranged at both end portions in a direction perpendicular to the rotation direction of the transport belt in the rotational direction of the transport belt, and provided so as to be exposed from the surface layer of the transport belt. 2. The sheet attracting / conveying apparatus according to claim 1, wherein the power feeding means movably provided at an upper portion of the sheet feeding unit is configured to be capable of contacting and supplying power to the power receiving unit. 3. The power supply unit moving means moves the power supply means in a vertical direction or rotates the power supply means about a rotation axis to move the power supply means toward and away from the power supplied part. The sheet suction / conveyance device according to claim 1 or 2, wherein: 4. The sheet suction and transport device according to claim 1, wherein the operation mode is a mode in which a sheet is not transported. 5. A recording apparatus comprising: the sheet suction / conveyance apparatus according to claim 1; and recording means for recording an image according to image information. 6. The recording apparatus according to claim 5, wherein said recording means is configured by an ink jet recording system for performing recording by discharging ink according to a signal. 7. The recording apparatus according to claim 6, wherein said recording means discharges the ink from the discharge port by utilizing film boiling generated in the ink by thermal energy applied by the electrothermal transducer. apparatus.