JPH10193725A - Unit for holding and rotary transferring medium in ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To rotary transfer a medium while holding surely and stably on a rotary member. SOLUTION: The inventive unit comprises means 21 for imparting charge attraction force to at least one of a rotary member (drum 10) and an objective medium (print medium M), means 40 for removing residual charges from the rotary member 10, 12 side after releasing the objective medium, and means 50 for removing residual matters adhering to the outer circumferential surface 11 of the rotary member 10. At least after removing residual charges, a next objective medium M can be charged and adhering matters can be removed at a good timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a medium holding / rotating / transporting apparatus for an ink jet printer for holding a medium to be held such as paper on a rotating member while utilizing a charge attracting force and transferring the medium using the rotation of the rotating member. .

[0002]

2. Description of the Related Art For example, a nozzle head for each color is reciprocated over the entire length in a row direction, and printing is performed during each forward movement to print one line, and after printing one line, a printing medium (plain paper, OHP) is printed.
Paper, etc.) M can be printed one line in the column direction and repeated, so that a so-called serial type ink jet printer can greatly increase the printing speed and can perform continuous printing operation over many sheets. The present applicant has proposed an ink jet printer capable of achieving a significant reduction in size as compared with (for example, Japanese Patent Application No. 8-296959).
No.).

In FIG. 7, a drum (rotating member) 10 is rotatable at a constant peripheral speed and can hold a print medium M on an outer peripheral surface 11 thereof. That is, the print medium (medium to be held) M is held on the outer peripheral surface 11 of the drum 10 by using the holding force of the medium holding means, and is rotationally transferred by using the rotation of the drum 10.

A nozzle head (print head) 200 for each color is arranged in the rotation (Y) direction of the drum 10. Therefore, an integrated nozzle head 200 for each color or an integrated nozzle head 200 for each color in which a plurality of nozzle head elements are arranged in the row direction over the entire length in the row direction (perpendicular to the paper surface), for example, by the pitch between inkjet nozzles. Ink is sprayed from the inkjet nozzles 207 for each color onto the rotating print medium M while being reciprocated, thereby printing in the row direction, and printing in the column direction using the rotation of the drum 10 during the forward movement of the pitch between the inkjet nozzles. Can be. That is, since the line-direction printing and the column-direction printing can proceed simultaneously, the printing speed can be greatly increased.

Further, since the nozzle heads 200 for each color and the ink tanks (ink cassettes) 213 for the respective colors are arranged at separate positions, the nozzle heads 200 for the respective colors are provided.
In addition to the fact that the printing speed can be reduced and the reciprocating speed in the row direction can be greatly increased, the printing speed can be further increased, and the capacity of the ink tank (ink cassette) 213 for each color can be greatly increased. This allows continuous printing operation.

In order to realize these, a medium feeding means 60 and a medium feeding means 90 are provided on one side (right side in FIG. 7) of the drum 10, and a medium is provided on the other side (left side in FIG. 7). Peeling means 140, medium discharging / conveying means 160, and direction switching means 1
90 are provided.

The medium feeding means 60 includes a cassette feeding means 7.
The print medium M can be selectively fed one sheet at a time from either one of the manual feeding means 61 and the manual feeding means 61. Medium supply means 90
Supplies the fed print medium M to the drum 10 at a predetermined timing. The medium peeling means 140 peels the print medium M from the drum 10 after printing, and the medium discharge / transport means 160 discharges and transports the peeled print medium M leftward in FIG. The direction switching unit 190 selectively switches between the discharge tray 192 and the upper discharge tray 193.

Thus, the feeding, supply, holding, rotational transfer, printing, peeling, and discharging and conveying of the printing medium M can be continuously performed, so that multicolor printing of, for example, 20 sheets or more of A4 size in one minute can be performed. it can. That is, if the printing medium (medium to be held) M is rotated and transferred using the medium holding rotary transfer device (10 or the like), high-speed printing can be performed.

Here, to obtain the rotation holding force,
It is conceivable to construct by using any one or an arbitrary combination of the charge attraction (adsorption) force, the negative pressure adsorption force, and the mechanical clamping force. In particular, for miniaturization, it is necessary to employ a charging means using the charge adsorption force. Influential.

[0010]

The charging means is formed of a charger that charges (charges) the medium to be held (M) in a non-contact manner or a charging roller that charges (charges) in contact with the medium (M). In any case, considering that the level of the negative electrode (ground) of the drum 10 is constant, for example, the stronger the charging means applies to the holding target medium (M), the more the rotational holding force (charge adsorption) on the drum 10 becomes. Power) can be increased.

However, if too much electric charge is applied to the entire area of the holding target medium (M), not only the rotation holding force becomes unstable, but also the floating of the holding target medium, spark discharge, and the like easily occur. In particular, there is a possibility that ink jetting (flying) may be disturbed, and printing quality may deteriorate. On the other hand, if the applied charge is weakened as a whole, the rotation holding force is naturally weakened, so that the holding target medium skews or peels off from the drum 10 (11). Therefore, it is difficult to further increase the printing speed by increasing the rotation speed of the drum 10.

Thus, the charging ability is carefully selected and determined, but still the charging ability becomes unstable or deteriorates from time to time. In addition, missing dots may occur.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a medium holding / rotating / transporting apparatus of an ink jet printer which can hold and hold a medium to be held on a rotating member reliably and stably.

[0014]

According to a test study, even if the charging ability (voltage value, charge amount, etc.) directly or indirectly applied to the holding target medium by using the charging means is fixed.
Depending on the material of the rotating member and the type of the medium to be held, as well as the purpose of use and, for example, the printing operation mode, the charging ability is lowered and the stability of the holding rotation transfer is changed.

In this connection, further analysis reveals that even when the medium to be held is removed from the rotating member, electric charges may remain on the rotating member, and the residual electric charges may interfere with the charging (charge application) by the charging means. Case was found. Also, the type and use of the storage target medium (for example, printing)
Depending on the purpose, especially when the continuous operation time is long, foreign matter such as paper dust and fine dust adheres to the outer peripheral surface of the rotating member, and the adhered substance not only deteriorates the stability but also the surface in contact with the outer peripheral surface of the holding target medium. It is the cause of dirt. Furthermore,
The paper dust or the like has an adverse effect on ink ejection, and may cause a missing dot.

Thus, according to the present invention, the charge remaining on the rotating member after the holding medium is released from the rotating member (peeling) is removed, and the next holding medium is formed so as to be held. In order to achieve the above object, paper dust and the like adhering to the rotating member can be removed at appropriate times (for example, every day).

According to a first aspect of the present invention, there is provided a charging means for charging at least one of a rotating member and a holding medium to obtain a charge attracting force, and removing a charge remaining on the rotating member after holding of the holding medium is released. And a deposit removing means for removing deposits remaining on the outer peripheral surface of the rotating member. After removing at least residual charges, charging for the next holding target medium can be performed. It is characterized in that it is formed so as to be able to remove attached matter in a timely manner.

In this invention, after the holding target medium is released from the rotating member (released), the charge removing means removes the charge remaining on the rotating member side. Therefore, since the initial state of the rotating member with respect to each of the following holding target media can be kept constant, the charging ability can be maintained and stabilized. That is, the holding target medium can be reliably and stably held and rotationally transferred to the rotating member. Further, for example, the attached matter removing means removes the attached matter remaining on the outer peripheral surface of the rotating member every day, so that the charging ability can be further stabilized and the occurrence of missing dots can be avoided.

A second aspect of the present invention is a medium holding rotary transfer device of an ink jet printer, wherein the charging means is formed of a conductive rubber charging roller.

In this invention, since the charging means is formed of a direct charging type charging roller made of conductive rubber,
In addition to having the same operation and effect as the case of the invention of claim 1,
Furthermore, the charging efficiency can be increased because the rotating member or the medium to be held can be contacted and directly charged, and the medium to be held can be mechanically pressed against the outer circumferential surface of the rotating member, so that the adhesion to the outer circumferential surface can be further promoted. it can.

Further, according to a third aspect of the present invention, the electric resistance value of the charging roller is 1 × 10 ⁶ Ω-cm or less and the outer peripheral surface of the rotating member is 1 × 10 ¹² to 1 × 10 ²⁰ Ω-cm.
Wherein the electric insulating layer is formed, the charge removing means is formed of a charge removing brush, and the deposit removing means is formed of a cleaning blade.

According to this invention, a high-resistance electric insulating layer having a larger electric resistance value than the electric resistance of the charging roller is formed on the outer peripheral surface of the rotating member, the electric charge removing means is formed by a discharging brush, and the deposit removing means is formed by a cleaning blade. So
In addition to providing the same operational effects as those of the first and second aspects of the present invention, the charging efficiency is further enhanced, and the residual charge and the attached matter are more reliably removed without damaging the outer peripheral surface of the rotating member. it can.

Further, the invention according to a fourth aspect of the present invention is directed to a medium holding and rotating apparatus for an ink jet printer, wherein the charging roller, the discharging brush and the cleaning blade are respectively formed so as to be able to come into contact with and separate from an outer peripheral surface of the rotating member or an electrically insulating layer. It is a transfer device.

According to this aspect of the invention, for example, the charging roller can be separated from the outer peripheral surface of the rotating member or the holding target medium before the holding target medium is supplied or after the holding target medium is held. It does not cause a load and does not affect the print quality on the holding target medium, for example. Further, the cleaning blade or the neutralizing brush can be brought into contact with the outer peripheral surface only while the holding target medium is not held and rotated and transferred. Therefore, the same operation and effect as those of the first to third aspects of the invention can be obtained, and furthermore, the rotating member (outer peripheral surface), the charging roller, the cleaning blade,
The service life of the neutralization brush can be extended and the medium does not interfere with the medium held by the rotating member.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the present medium holding rotary transfer device includes a charging unit 21 for charging at least one of a rotating member (drum 10) and a holding target medium (print medium M) to obtain a charge attracting force; Charge removing means 40 for removing the charge remaining on the rotating member [10 (12)] after the holding of the medium is released, and an outer peripheral surface 1 of the rotating member (10).
1 (12) is provided with an extraneous matter removing means 50 for removing extraneous matter, and after at least residual charge is removed, charging for the next holding target medium (M) can be performed and the extraneous matter can be timely performed. It is formed so that removal can be performed.

The basic configuration of the ink jet printer is the same as that of the previously proposed ink jet printer (FIG. 7), and a case where the printing medium (holding target medium) M is held and rotated in the Y direction will be described. The description of the same parts as those in FIG. 7 will be simplified or omitted.

In FIG. 1, the rotating member is formed of a drum 10 having a hollow portion 14, and is rotatable at 120 rpm capable of achieving multi-color printing at 20 PPM. The shaft 15 serving as the rotation center is connected to a ground (open space) by an earth wire 19 so as to be able to discharge.

On the outer peripheral surface 11 of the drum 10, an electric insulating layer 12 having an electric resistance value (volume resistivity) of 1 × 10 ¹² to 1 × 10 ²⁰ Ω-cm is formed. This is to secure a surface potential (for example, 500 V or more) after charging. In this embodiment, the thickness 2 is closely adhered to the drum outer peripheral surface 11.
It is formed from a 5 μm Mylar sheet. In addition, a recess 13 is provided in a part of the outer peripheral surface 11 so that the tip of the medium peeling means (peeling claw) 140 can temporarily enter therein.

Around the drum 10, a medium supply unit 90, a charging unit 21 and a replenishment charging unit 25 forming a medium holding unit 20, a charge eliminating unit 30, a medium peeling unit 140, a nozzle (printing) head 200 , The attached matter removing means 50 and the charge removing means 40 rotate in this order (Y).
It is arranged from the upstream side in the direction to the downstream side.

The medium supply means 90 includes a pair of supply rollers 9.
In addition to the medium supply function to the drum 10
It has a function of adjusting the attitude of the print medium M and a function of standby for supply.

That is, the leading end of the print medium M fed from below in FIG.
3 and is elastically deformed in the guide 94 on the upstream side. Therefore, the leading end of the print medium M is placed on the drum (shaft 1).
5) It can be supplied without skew because it is aligned in the axial direction.
The elastic restoring force of the print medium M in the guide 94 can promote the posture adjusting force. Whether or not the posture adjustment process has been started can be confirmed by the medium sensor 97.

When the posture adjustment is completed, both rollers 9
Reference numerals 1 and 92 move the print medium M to the drum 10 side along the downstream guide 96 until the leading end of the print medium M is detected by the medium sensor 98. Therefore, since the leading end side of the print medium M is bitten by the rollers 91 and 92, the trailing end side is provided below the guide 94 by the cassette feeding means (71) or the manual feeding means (61).
Can be free. In other words, at this point, the feeding process for the next printing medium M is completed, and a supply standby state to the drum 10 can be established. This is effective for speeding up printing.

The printing medium M can be supplied to the drum 10 (11) at a predetermined timing. After the leading end of the supplied print medium M is held on the outer peripheral surface 11, the one roller 91 is moved rightward as shown by a two-dot chain line in FIG. Therefore, the rear end side of the print medium M becomes free, and does not become a load of the rotation transfer by the drum 10.

The charging means 21 may be either a direct (contact) charging method using a charging roller or the like or an indirect (non-contact) charging method using a corona discharger or the like in relation to the charge removing means 40 and the attached matter removing means 50. However, in this embodiment, the former is adopted.

That is, the charging means 21 can be selectively switched between the solid line state (contact) and the two-dot chain line state (separation) shown in FIG. 1 by the reciprocating means 29 shown in FIGS. A charging roller 23 capable of directly charging the print medium M (or the electrical insulating layer 12);
And a power supply 22 for applying, for example, DC + 1.5 kV.

The charging roller 23 is made of a conductive rubber having an electric resistance value (volume resistivity) of 1 × 10 ⁶ Ω-cm or less.
The conductive rubber is selected from urethane rubber, silicone rubber, and the like. In this embodiment, the conductive rubber is urethane rubber.

The replenishment charging means 25 forming the medium holding means 20 together with the charging means 21 is formed of a corona discharger capable of discharging a positive charge by applying, for example, 4 kV, and while the drum 10 is rotating (especially the nozzle head). In order to maintain the constant charge attraction force by compensating for the charge attraction force attenuated during the printing using (200), the charge is replenished to the holding target medium (M).

As shown in FIG. 2, the advancing / retracting means 29 includes a link lever 29L which can rotate around a pin member 29P,
A spring 29SP for pulling one side (upper side) 29LF of the link lever 29L to the left in the drawing, and an eccentric cam 29C for pressing the other side (lower side) 29LB downward in the figure against the pulling force of the spring 29SP. Consists of The charging roller 23 is rotatably mounted on a link lever 29L via a support shaft 29S.

Therefore, the other side 29
When the LB is not pushed down, the spring 29
The charging roller 23 can be brought into contact with the drum outer peripheral surface 11 (12) or the print medium M by the urging force (tensile force) of the SP. In addition, they come into contact with a certain pressing force. If the other end 29LB is pushed down by the eccentric cam 29C, the charging roller 23 can be separated from the drum outer peripheral surface 11 (12).

The charging roller 23 is formed so as to be in contact with the printing surface side of the holding target medium (M) and to perform charging for obtaining a charge attracting force.
(12)]. That is, at least one of the rotating member [10 (12)] and the holding target medium (M) may be charged.

The charge eliminating means 30 is formed of a corona discharger to which an AC potential can be applied. Prior to the mechanical peeling by the medium peeling means 140, the charge eliminating means 30 is provided between the outer peripheral surface 11 (12) and the print medium M. The charge adsorption force can be eliminated. The replenishment charging means 25 is based on reverse charging.

The adhering substance removing means 50 comprises a cleaning blade 52 made of urethane rubber, and is fixed to the front end of the case 51. That is, by adhering the tip (edge) of the cleaning blade 52 at an acute angle, it is possible to scrape off deposits such as paper dust and fine dust remaining on the rotating drum outer peripheral surface 11 (12). Case 5
A dust box 55 having a collection space 56 can be attached to and detached from (within 1). This is for convenience of disposal of the collected paper powder and the like. Further, a static elimination brush 42 forming the charge removing means 40 is attached to the case 51 via a holding member 41.

The neutralizing brush 42 and the cleaning blade 52 are respectively connected to the outer peripheral surface 11 of the drum 10.
(Or the electrically insulating layer 12). In this embodiment, the processing is executed by the common elevating means 59 shown in FIG. That is, the lifting / lowering means 59 is
Are formed so as to be able to ascend and descend to a lower position shown in FIG. 4B, a first upper position shown in FIG. 4A, and a second upper position shown in FIG.

That is, the removal of the residual charges on the drum outer peripheral surface 11 (12) by the charge removing means 40 (42) is preferably performed after the printing of each print medium M is completed. Since the adhering matter needs to be removed only once every 1 to 2 days, it was formed in a two-stage ascent system. The elevating means 59 may be appropriately constructed from a cam driving method similar to the moving means 29, such as a solenoid driving method, an air cylinder driving method, a motor driving method, or the like.

The drive control unit 250 shown in FIG.
Although the entire printer including the ROM and the RAM can be drive-controlled, those not directly related to the apparatus are not shown.

In the case of this embodiment, the drive control unit 250
When the apparatus power is turned on (ON), the main motor 10M is rotated at a low speed (ST10 in FIG. 5), and the elevating means 59 is moved from the state shown in FIG. It is raised (ST11) to the position above the second stage shown.
Therefore, the cleaning blade 52 is used for the electric insulating layer 1.
2 can be removed (scraped) from the attached matter. The removed deposits are collected in the dust box 55 (56). Since the drum 10 is rotated at a low speed, a stable removing operation can be performed, and the service life of both the drums 11 (12) and 52 can be extended.

Further, the charge removing brush 42 comes into contact with the electric insulating layer 12 to remove the residual charge on the drum 10 side. This initialization is ended by an automatic or manual command (YES in ST12).

When the initialization is completed, the drive control section 250 drives the lifting / lowering means 59 to move the attached matter removing means 50 (52) and the charge removing means 40 (42) to the original lower position shown in FIG. Lower (ST13) and the main motor 10
M is switched to high-speed rotation (ST14).

Thereafter, the drum rotation position detector 10S
As a result, it is detected that the rotational position (angle) of the drum 10 has reached a preset rotational position (Y in ST15).
ES), the print medium M which has been in the supply standby state by driving the medium supply means 90 is supplied to the drum 10 shown in FIG. 1 at a moving speed equivalent to the drum peripheral speed (ST1).
7).

Prior to this (or simultaneously), the advancing / retreating means 29 is driven to advance the charging roller 23 from the two-dot chain line state of FIG. 1 to the solid line state (ST16). The charging roller 23 comes into contact with the drum outer peripheral surface 11 (electric insulating layer 12) with a constant pressing force. The drive control unit 250 controls the printing medium M
The power source 22 is turned on immediately before or simultaneously with the contact with the charging roller 23 to apply voltage to the charging roller 23.

Therefore, the leading end of the supplied printing medium M is rotated by the rotation of the drum 10 so that the charging roller 2 rotates.
The printing medium M can be charged from the point in time when the printing medium M enters the gap between the printing medium 3 and the electrical insulating layer 12. That is, a charge is applied to the leading end of the print medium M, and the charge can be immediately held on the outer peripheral surface 11 (12) of the rotating member (10) by the charge attracting force.

When the holding of the leading end is established, in this embodiment, when it is confirmed from the output signal of the drum rotation position detector 10S, the drive control unit 250 moves the one roller 91 of the medium supply means 90 to the two points in FIG. Move to dashed line state. Therefore, the rear end side of the print medium M is free from the rollers 91 and 92, so that the rotation transfer load of the drum 10 is not generated.

Thus, the printing medium M is charged on the outer peripheral surface 11 of the drum by the charge attracting force given by the charging means 21.
(Electrically insulating layer 12), and is rotationally transported in the Y direction as the drum 10 rotates. The charging roller 23 is driven and rotated and presses the printing medium M toward the drum outer peripheral surface 11 (12) while pressing the printing medium M from the front end side to the rear end side. Adhesion can be further improved.

During one rotation of the drum 10, when the drum rotation position detector 10S detects (confirms) that the rear end of the printing medium M has passed the charging roller 21 (ST)
18 (YES), the charging roller 21 is retracted by the advance / retreat means 29 to the two-dot chain line state in FIG. Therefore, the print medium M is held on the drum outer peripheral surface 11 (12) only by the charge attracting force and is rotationally transferred in the Y direction.

The ink is jetted from the nozzle head (inkjet nozzle) 200 during the rotation of the drum 4 (2 to 5) thereafter, and printing is performed on the print medium M which is being rotationally transferred. During this period, the charging means 25 for replenishment operates, and the charge attraction force is kept constant. In addition, the drive control unit 250 activates the medium supply unit 90 to set the next print medium M in a supply standby state.

When the multi-color printing on the print medium M of, for example, A4 size is completed by four rotations of the drum (YES in ST20 of FIG. 6), the drive control unit 250 activates the charge eliminating means 30 to switch the print medium M with print. The electric charge attracting force between the electric insulating layer 12 is eliminated (ST21), and the leading end side of the print medium M with print is mechanically peeled by operating the medium peeling means 140 (ST22). The peeled print medium M is
The medium is delivered to the medium discharge / conveying means (160) by a medium peeling means (peeling claw) 140 which also serves as a delivering means.

The drive control section 250 drives the lifting / lowering means 59 to raise the charge removing means 40 to the first stage upper position shown in FIG.
T23). Therefore, the charge removing brush 42 removes the charge remaining on the electric insulating layer 12.

Hereinafter, printing is performed while the print medium M is successively rotated while being held. End of printing operation (YES in ST24)
Then, the drive control unit 250 rotates the main motor 10M again at a low speed (ST25) and activates the elevating means 59 to raise the case 51 to the second upper position shown in FIG. 1 (S25).
T26).

Accordingly, the cleaning blade 52 removes deposits remaining on the drum outer peripheral surface 11 (12), and the charge removing brush 42 removes residual charges on the electric insulating layer 12. It is executed for a preset time Ts (ST27). Thereafter, the case 51 is lowered to the lower position shown in FIG. 4B (ST28).

According to this embodiment, the charging means 21 for charging at least one of the rotating member (drum 10) and the holding medium (print medium M) to obtain a charge attracting force, and the holding medium Charge removing means 40 for removing the charge remaining on the rotating member [10 (12)] after the holding of the rotating member [10 (12)], and the attached matter removing means 50 for removing the attached matter remaining on the outer peripheral surface 11 (12) of the rotating member (10). After the residual charge has been removed, charging for the next holding target medium (M) can be performed, and the attached matter can be removed in a timely manner. Can be stabilized. Therefore, the holding target medium (M) can be reliably and stably held and rotationally transferred to the rotating member (10).

Further, since the charging means 21 is made of conductive urethane rubber and is formed of the charging roller 23 of the direct charging type, the charging efficiency can be increased and the charging target medium ( M) can be mechanically pressed against the outer peripheral surface 11 (12) of the rotating member (10), so that the adhesion to the outer peripheral surface 11 (12) can be further promoted.

The electric resistance of the charging roller 23 is 1 ×
An electric insulating layer 12 of 1 × 10 ¹² to 1 × 10 ²⁰ Ω-cm is formed on the outer peripheral surface 11 of the rotating member (10) or less at 10 ⁶ Ω-cm or less. And the adhering matter removing means 50 is formed of a cleaning blade 52 made of urethane rubber, so that the charging efficiency can be further improved and the outer peripheral surface 11 (12) of the rotating member (10) is damaged. Deposits and residual charges can be removed without attaching.

Since the charging roller 23, the discharging brush 42, and the cleaning blade 52 are formed so as to be able to contact and separate from the outer peripheral surface 11 of the rotating member (10), that is, the electrical insulating layer 12, the rotating member 10 [the outer peripheral surface] 11
(12)], charging roller 23, cleaning blade 5
(2) The life of the neutralization brush 42 can be extended and the medium (M) held on the rotating member does not interfere.

Further, since the charging roller 23 is formed to be rotatable following the rotation of the drum 10, the rotating member (1
0), not only does not give an unnecessary external force causing wrinkles or the like to the holding target medium (M) without causing the rotation load of (0), but also it can be squeezed from the front end side to the rear end side.
1 (12) can be further enhanced.

Further, since the charging roller 23 can be pressed against the drum outer peripheral surface 11 (12) by the urging force (tensile force) of the spring 29SP when the advance / retreat means 29 is in the forward state, the printing medium M is Outer peripheral surface 11 (1
Adhesion to 2) can be further enhanced.

Further, the elevating means 59 is connected to the case 51 (4
0, 50) can be raised by two steps, so that the charge can be removed each time printing of each printing medium M is completed, and paper dust or the like adhered to the drum outer peripheral surface 11 (12) at the end of the printing operation (timely). Can be removed.

Further, since the medium supply means 90 has a posture adjustment function and a supply standby function in addition to the medium supply function, the print medium M can be supplied and held to the drum 10 without skew. At the same time, the feeding process for the next printing medium M can be completed during the printing operation of the preceding printing medium M, so that the speed of the holding rotation transfer and the printing can be further increased.

Further, replenishing charging means 25 is provided,
Since the charge adsorption force attenuated during the holding rotation transfer and during printing is formed so as to be replenished, the holding rotation transfer can be more reliably performed.

Further, a charge eliminating means 30 is provided,
After the holding rotation transfer (printing operation), the charging means 20 (21, 21)
Since it is formed so that the charge adsorbing force according to 5) can be eliminated, mechanical peeling (holding release) by the medium peeling means 140 is performed.
Can be smoothed.

Further, since the dust box 55 is provided in the case 51 so as to be removable (scraped), it is easy to treat the removed (scraped) paper dust, fine dust and the like.

[0071]

According to the first aspect of the present invention, there is provided a charging unit, a charge removing unit, and an adhering matter removing unit, and after at least residual charge has been removed, charging for the next holding target medium is performed. Since the medium to be held is formed so as to be able to perform and remove the attached matter in a timely manner, the medium to be held can be held and rotated and transferred to the rotating member reliably and stably. Further, for example, it is possible to remove the deposits remaining on the outer peripheral surface of the rotating member every day, so that the charging ability can be further stabilized and the occurrence of missing dots can be avoided.

According to the second aspect of the present invention, since the charging means is formed of a conductive rubber charging roller, the same effect as that of the first aspect of the invention can be obtained. The charging efficiency can be increased because the holding target medium can be contact-charged, and the holding target medium can be mechanically pressed against the outer peripheral surface of the rotating member, so that the adhesion to the outer peripheral surface can be further promoted.

Further, according to the third aspect of the present invention, the electric resistance of the charging roller is set to 1 × 10 ⁶ Ω-cm or less and the outer peripheral surface of the rotating member is set to 1 × 10 ¹² to 1 × 10 ²⁰ Ω-cm. Since the electric insulating layer is formed, the charge removing means is formed by the charge removing brush and the deposit removing means is formed by the cleaning blade, the same effect as in the inventions of claim 1 and claim 2 can be obtained. In addition to this, the charging efficiency can be further enhanced, and the deposits and residual charges can be more reliably removed without damaging the outer peripheral surface of the rotating member.

Furthermore, in the invention according to claim 4, the charging roller, the charge removing brush and the cleaning blade are formed so as to be able to come into contact with and separate from the outer peripheral surface of the rotating member or the electric insulating layer, respectively. In addition to achieving the same effects as those of the inventions up to 3, the life of the rotating member (outer peripheral surface), the charging roller, the cleaning blade, and the discharging brush can be extended, and interference with the medium held by the rotating member can be achieved. Absent.

[Brief description of the drawings]

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

FIG. 2 is also a view for explaining an advance / retreat means.

FIG. 3 is a block diagram for explaining a drive control unit.

FIG. 4 is a diagram for explaining the operation.

FIG. 5 is also a flowchart (1) for explaining the operation.

FIG. 6 is also a flowchart (2) for explaining the operation.

FIG. 7 is a diagram for explaining a previously proposed inkjet printer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Drum (rotating member) 11 Outer peripheral surface 12 Electrical insulating layer 15 Shaft part 20 Medium holding means 21 Charging means 22 Power supply 23 Charging roller 25 Replenishment charging means 29 Advance / retreat means 30 Charge elimination means 40 Charge removal means 41 Holding member 42 Static elimination brush 50 Adhered matter removing means 51 Case 52 Cleaning blade 55 Dust box 59 Elevating means 90 Medium supply means 200 Nozzle head 207 Inkjet nozzle M Print medium (medium to be held)

Claims (4)

[Claims] A charging means for charging at least one of the rotating member and the holding medium to obtain a charge attracting force; and a charge removing means for removing charges remaining on the rotating member after releasing the holding of the holding medium. An adhering substance removing means for removing adhering substances remaining on the outer peripheral surface of the rotating member, performing charging for the next holding object medium after at least removing residual charges, and removing adhering substances in a timely manner A medium holding and rotating transfer device for an ink jet printer, wherein the device is formed so as to be executable. 2. The apparatus according to claim 1, wherein said charging means is formed of a conductive rubber charging roller. 3. An electric resistance value of the charging roller is 1 × 10.
⁶ Ω-cm or less and 1 ×
The electric insulating layer of 10 < ¹² > to 1 * 10 < ²⁰ > [Omega] -cm is formed, the charge removing means is formed of a discharging brush, and the deposit removing means is formed of a cleaning blade. 3. A medium holding rotary transfer device of the ink jet printer according to 2. 4. The method according to claim 1, wherein the charging roller, the charge removing brush and the cleaning blade are respectively formed so as to be able to come into contact with and separate from an outer peripheral surface of the rotating member or an electric insulating layer. The described media holding rotary transfer device of an ink jet printer.