JP2001031278A - Electrostatic adsorption type drum printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely attract the tip and the rear end of a printing medium to a peripheral surface of a rotary drum while reducing an electrifying quantity as a whole by constituting so as to electrify a tip part and a rear end part of the printing medium to the rotary drum as well as to partially electrify a part between the tip part and the rear end part. SOLUTION: A rotation angle detecting means 130 is arranged on an end surface of a rotary drum 110, a tip detecting object 132 and a rear end detecting object 133 are arranged, and a light transmissive detector 131 is installed on the stationary side opposed to these detecting objects. A revolution sensor is composed of these rotation angle detecting means 130 (131 to 133) to respectively detect a tip part and a rear end part of a printing medium (paper) P whether or not a rotation angle of the rotary drum 110 is an electrostatically attractable angle. An electrifying driving control means can partially electrify and attract a part between the tip part and the rear end part of the printing medium P by electrifying/driving an electrifying charger 120 when detecting that the timing is adjusted to a relative turning angle capable of electrifying the tip part of the printing medium P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating drum, in which a printing medium can be held by using an electrostatic attraction force applied to the rotating drum by using a charger, and the held printing medium can be rotated by rotating the rotating drum. The present invention relates to an electrostatic attraction type drum printer formed so as to be rotatable and capable of printing by rotating a head on a printing medium being rotated.

[0002]

2. Description of the Related Art A nozzle head for each color, in which an ink cassette is mounted, is reciprocated over the entire length in a row direction, and printing is performed during each forward movement to print one line (or 1 / N line). Compared to a so-called serial type ink jet printer in which a printing medium (plain paper, OHP paper, etc.) is fed one line in the column direction after printing one line (or 1 / N line) and repeating these, the printing speed is greatly increased. The present applicant has proposed an inkjet printer that can achieve continuous printing operation over a large number of sheets and can achieve a significant reduction in size as compared with a so-called laser printer of an electrophotographic system (for example,
JP-A-10-138516).

In FIG. 7, which shows an ink jet printer similar to that of the above proposal, a printing medium (paper) sent from a paper cassette 101 (or a manual feed tray 102) is rotated by a feeding roller 103 at a predetermined timing. The paper is fed to the side 110 and wound and held on the outer peripheral surface (printing surface) of the rotating drum 110. Rotating drum 110
Is about the axis Z and in the direction of rotation (R), for example, 12
Rotated at 0 RPM.

In addition, each color has a large number of ink jet nozzles and is integrated (or integrated with a plurality of nozzle head elements arranged in the row direction) over the entire length in the row direction (printing direction--perpendicular to the paper surface). Nozzle heads 15C, 15
Each color ink (cyan C, magenta M, yellow Y, black K) can be ejected (jetted) from M, 15Y, 15K.

Thus, the nozzle head unit 10 (1
5C, 15M, 15Y, and 15K) are reciprocated by a predetermined distance (for example, the pitch between inkjet nozzles) in the printing (row) direction by the reciprocating moving means, and are printed in the row direction on the rotating rotating drum 110, that is, the print medium. At the same time, printing in the column direction can be performed while utilizing the rotation of the rotating drum 110.

That is, since the row-direction printing and the column-direction printing can proceed simultaneously by utilizing the high-speed rotation of the rotary drum 110, the printing speed is greatly increased (for example, 20 PPM).
Can be achieved. When printing of one page is completed, the nozzle head unit 10 is moved backward to return to the original position, and thereafter, the forward movement of the next page is started.

The printed print medium is supplied to a rotating drum 110
And is discharged to the stack portion 106 on the upper side of the main body case 100 by the discharge roller 104. The nozzle head unit 10 includes the ink cassette 1
12, each color ink is supplied from an ink supply means including an ink supply pump 113 and the like.

In order to carry out continuous printing operation on such a large number of print media, it is important to accurately and stably mount and peel the print media on the rotating drum 110. Therefore, as shown in FIG. 8, a tip chuck mechanism 41 for mechanically nipping the leading end of the printing medium (paper P) supplied to the peripheral surface of the rotating drum 110, and the trailing end of the printing medium are cut into the rotating drum 110. And a trailing end chuck mechanism 42 that is inserted into the locking groove and formed so as to prevent its floating.
The rear end is formed so as to be closely wound around the peripheral surface of the rotating drum 110.

Further, an electrical insulating film is formed on the peripheral surface of the cylindrical rotary drum 110 made of metal (for example, aluminum), and the print medium is uniformly spread on the peripheral surface by using a charger (charging charger 120). It is formed so that it can be electrostatically attracted,
A device has been devised to prevent floating in the middle of the print medium.

[0010]

The printing medium can be held on the peripheral surface of the rotating drum 110 by utilizing the electrostatic attraction force applied by using the charging charger 120, and is rotationally transferred by using the rotation of the rotating drum 110. In an electrostatic attraction type drum printer formed so as to be able to print by driving the nozzle heads 15C, 15M, 15Y, and 15K on the inner printing medium, the more the electrostatic attraction force is increased by strong charging by the charging charger 120, the better. In addition, the printing medium can be surely sucked, and floating in the middle can be prevented.

However, the electrostatic attraction seen from the peripheral surface of the rotating drum 110 is not effective only for the print medium. That is,
Paper dust and nozzle heads 15C, 15 scattered from the print medium
It also acts on ink from M, 15Y, 15K and dust floating in the air, so that the dust and the like easily adhere to the rotating drum 110 and the nozzle heads 15C, 15M, 15Y, 15K.

[0012] Such adhesion of dust and the like not only deteriorates the printing quality but also causes a failure. Therefore, it is necessary to frequently perform maintenance for wiping out the attached dust and the like. This hinders high-speed printing.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrostatic attraction type drum printer capable of reducing the overall amount of charge and the amount of dust adhered while ensuring the effect of preventing the print medium from floating in the middle.

[0014]

According to the first aspect of the present invention, a print medium can be held by using the electrostatic attraction force applied to the rotary drum by using a charging charger, and the print medium held by the rotary drum is rotated. In an electrostatic attraction type drum printer which is formed so as to be rotatable and transferable by using rotation and is capable of printing by driving a head on a printing medium being rotated, the charging charger is rotated at a rotation angle of the rotating drum. And the charging drive / stop can be switched, and the leading end and the trailing end of the print medium with respect to the rotating drum can be electrostatically attracted to the rotating drum and the gap between the leading end and the trailing end can be set. This is an electrostatic attraction type drum printer formed so as to be partially chargeable and attractable to the rotating drum.

According to the invention, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the leading end portion of the printing medium can be charged and attracted to the rotating drum, the charging charger is driven to be charged.

Thereafter, the charging charger is stopped and the charging is driven again, and switching is performed so as to repeat this driving / stopping. That is, the portion between the front end portion and the rear end portion of the print medium can be partially (intermittently) charged and adsorbed.

Further, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the rear end portion of the print medium can be charged on the rotating drum, the charging charger is driven to be charged.

Thus, since the leading and trailing ends of the print medium with respect to the rotating drum are charged and the portion between the leading and trailing ends is partially charged, the leading end of the print medium is reduced while reducing the overall charge amount. The rear end can be reliably attracted to the peripheral surface of the rotating drum, and the dust-free amount can be reduced by enlarging the non-charged area while ensuring the effect of preventing the print medium from rising in the middle.

According to a second aspect of the present invention, the printing medium can be held by using the electrostatic attraction force applied to the rotating drum by using a charging charger, and the held printing medium can be held by utilizing the rotation of the rotating drum. In the electrostatic attraction type drum printer which is formed so as to be rotatable and transferable, and is configured to be capable of printing by driving a head to a printing medium being rotated, the charging charger is charged at a timing corresponding to the rotation angle of the rotating drum. An electrostatic attraction type drum printer which is formed so as to be switchable between driving and stopping, and is formed so that a leading end portion and a trailing end portion of the printing medium with respect to the rotating drum can be electrostatically attracted to the rotating drum.

In this invention, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the rotating drum can charge the leading end portion of the print medium, the charging charger is driven to be charged.

After that, the charging charger is stopped. That is, there is no charging after the leading end. Then, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the rear end portion of the print medium can be charged on the rotating drum, the charging charger is driven to be charged again.

Thus, since the leading and trailing ends of the print medium with respect to the rotary drum are charged and the intermediate part is not charged, the overall charge amount is greatly reduced as compared with the first aspect of the present invention. The rear end can be reliably adsorbed to the peripheral surface of the rotary drum, and the effect of preventing floating in the middle of the print medium can be secured while reducing the amount of dust attached by greatly expanding the non-charged area. In particular, claim 1
This is effective for a print medium in which the size of the rotating drum in the rotation direction is shorter than that in the case of the invention.

According to a third aspect of the present invention, the printing medium can be held by using the electrostatic attraction force applied to the rotating drum by using a charging charger and the held printing medium can be rotated by using the rotation of the rotating drum. In the electrostatic attraction type drum printer which is formed so as to be rotatable and transferable, and is configured to be capable of printing by driving a head to a printing medium being rotated, the charging charger is charged at a timing corresponding to the rotation angle of the rotating drum. A drive / stop can be switched and a charging strength can be switched, and a leading end and a trailing end of the printing medium with respect to the rotating drum can be strongly electrostatically attracted to the rotating drum, and the leading end and the trailing end can be switched. This is an electrostatic attraction type drum printer formed so as to be weakly charged and attracted to the rotating drum.

According to this invention, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the leading end portion of the print medium can be charged on the rotating drum, the charging charger is strongly switched to perform the charging drive.

Thereafter, the charging charger is weakly switched to charge between the leading end and the trailing end, and the relative rotation angle between the rotating drum and the charging charger is adjusted to a timing at which the rotating drum can charge the rear end portion of the print medium. In the event that the charging becomes impossible, the charging charger is switched over again to drive the charging.

Thus, the leading and trailing ends of the print medium with respect to the rotating drum are strongly charged and the space between the leading and trailing ends is weakly charged. The rear end can be reliably attracted to the peripheral surface of the rotating drum, and the dust adhesion amount can be reduced by enlarging the weakly charged area while ensuring the effect of preventing the print medium from rising in the middle. This is effective for a print medium having a larger size than that of the first or second aspect of the invention.

Further, according to a fourth aspect of the present invention, the print medium can be held by using the electrostatic attraction force applied to the rotary drum by using a charging charger, and the held print medium can be rotated using the rotation of the rotary drum. In the electrostatic attraction type drum printer which is formed so as to be rotatable and transferable, and is configured to be capable of printing by driving a head to a printing medium being rotated, the charging charger is charged at a timing corresponding to the rotation angle of the rotating drum. A drive / stop can be switched and a charging strength can be switched, and a leading end and a trailing end of the printing medium with respect to the rotating drum can be strongly electrostatically attracted to the rotating drum, and the leading end and the trailing end can be switched. This is an electrostatic attraction type drum printer formed so as to be partially weakly chargeable and attractable to the rotary drum.

In this invention, when the relative rotation angle between the rotating drum and the charging charger reaches a timing at which the leading end of the print medium can be charged on the rotating drum, the charging charger is strongly switched to perform the charging drive.

Thereafter, the operation of stopping the charging charger and driving it again is repeated. During this period, the charging charger is driven by weakly switching the charging.

Then, when the relative rotation angle between the rotating drum and the charging charger reaches the timing at which the rear end portion of the print medium can be charged on the rotating drum, the charging charger is switched over again to perform charging driving.

Thus, the leading end and the trailing end of the print medium with respect to the rotating drum are strongly charged, and the gap between the leading end and the trailing end is weakly and partially charged. The leading and trailing edges of the print medium can be securely adsorbed to the peripheral surface of the rotating drum while greatly reducing the overall charge amount, and the weak charge while ensuring the floating prevention effect in the middle of the print medium Dust adhesion amount can be reduced by greatly expanding the area.

[0032]

Embodiments of the present invention will be described below with reference to the drawings. (First Embodiment) As shown in FIGS. 1 to 3, the present electrostatic attraction type drum printer has the same basic configuration and functions as those of the previously proposed printer (FIGS. 7 and 8), Charger 120 can be switched between charging and stopping by adjusting the timing of charger 120 to the rotation angle of rotating drum 110.
The front end and the rear end of the print medium (paper P) with respect to 10 can be electrostatically attracted to the rotating drum 110 and the rotating drum 110 can be partially charged and adsorbed between the leading end and the rear end. ing.

In FIG. 2, a rotating angle detecting means 130 is formed on the end face of the rotating drum 110, and a leading end detecting body 132 and a trailing end detecting body 133 formed of a light shielding plate are provided. Is mounted with a light transmission type detector 131.

The rotation angle detecting means 130 (131, 1
32, 133) form a circling sensor, and the rotating drum 1
It is detected that the rotation angle of 10 has reached an angle at which the leading end portion and the trailing end portion of the printing medium (paper P) can be electrostatically attracted to each other in relation to the charging charger 120.

The reference position (reference angle) of the rotary drum 110 has a number of slits and
1 can be detected in the engine controller 7 of FIG. 1 by using an output signal of an encode (not shown) composed of a slit disk fixed to be rotatable in synchronization with a sensor and a sensor.

The charging charger 120 can be driven (ON) or stopped (OFF) by a switching signal from the engine controller 7.

An image processing unit 5 in FIG. 1 performs predetermined processing of print data received in the printer or from the host computer and inputs the data to the engine controller 7. 10 is
In the nozzle head unit, each color nozzle head 15C,
15M, 15Y, and 15K (see FIG. 7) are integrally incorporated. Reference numeral 41 in FIG. 2 denotes a tip chuck mechanism.
Reference numeral 42 denotes a rear end chuck mechanism.

The charging drive control means (engine controller 7) includes the orbiting sensors (131, 13) shown in FIG.
It was detected at the output timing (rising) of the detection signal of 2), that is, the timing matched the relative rotation angle at which the leading end portion of the print medium holding the charging charger 120 and the rotating drum 110 can be charged. In case,
The charger 120 is charged (ON).

Thereafter, the charging charger is stopped (O
FF) and charging drive (ON) again, and switching is performed so as to repeat this drive / stop. This is managed by using the encoded output. That is,
The portion between the leading end and the trailing end of the print medium can be partially (intermittently) charged and adsorbed.

Further, the orbit sensors (131, 133)
At the output timing (rising edge) of the detection signal, that is, when the timing matches the relative rotation angle at which the charging charger 120 can charge the rear end portion of the print medium held by the rotating drum 110, the charging charger 12
0 is again charged (ON).

Thus, the leading end and the trailing end of the print medium with respect to the rotating drum 110 are charged, and the rotating drum 110 is partially charged (intermittently in the rotating direction) between the leading end and the trailing end (ON). ), The leading and trailing ends of the print medium are rotated by the rotating drum 110 while reducing the overall charge amount.
Can be reliably attracted to the peripheral surface of the print medium, and the amount of dust adhering can be reduced by enlarging the non-charged area while ensuring the effect of preventing floating in the middle of the print medium. Therefore, the maintenance interval for wiping dust and the like adhered to the peripheral surface of the rotary drum 110 and the tip end surface of the nozzle head 15 can be greatly extended, and the printing speed can be further improved.

(Second Embodiment) In a second embodiment, the basic configuration and functions are the same as those of the first embodiment (FIGS. 1 and 2).
, But as shown in FIG.
Only the leading and trailing end portions of the print medium with respect to 0 are formed to be chargeable.

That is, it is effective in the case of a print medium in which the size of the rotary drum 110 in the rotation direction is shorter than that of the first embodiment, and the space between the leading end and the trailing end of the print medium is effective. The structure is not charged.

That is, when the relative rotation angle between the rotating drum 110 and the charging charger 120 reaches a timing at which the leading end portion of the print medium can be charged and attracted to the rotating drum 110, the charging charger 120 is charged (ON). I do.

Thereafter, the charger 120 is stopped (OFF). That is, there is no charging after the leading end. Then, the rotating drum 110 and the charging charger 12
When the relative rotation angle to 0 reaches the timing at which the rear end portion of the print medium can be charged and adsorbed to the rotating drum 110, the charging charger 120 is driven to be charged again.

Thus, since the leading and trailing ends of the printing medium with respect to the rotating drum 110 are charged and the intermediate portion is not charged, printing is performed while greatly reducing the overall charging amount as compared with the first embodiment. The leading and trailing ends of the medium can be reliably attracted to the peripheral surface of the rotating drum 110, and the effect of preventing the floating of the print medium in the middle while reducing the amount of dust attached by greatly expanding the non-charged area can be ensured. It is.

(Third Embodiment) In the third embodiment, the basic configuration and functions are the same as those of the first embodiment (FIGS. 1 and 2).
2), but furthermore, as shown in FIG. 5, the charging drive / stop can be switched and the charging intensity can be switched in accordance with the timing of the rotation angle of the rotating drum 110 of the charging charger 120. Rotating drum 11
The leading and trailing end portions of the print medium with respect to 0 can be strongly electrostatically attracted to the rotating drum 110 and the charge between the leading and trailing end portions can be weakly charged and attracted.

That is, when the relative rotation angle between the rotating drum 110 and the charging charger 120 reaches a timing at which the leading end of the print medium can be charged and attracted to the rotating drum 110, the charging charger 120 is strongly switched to perform the charging drive. (ON).

Thereafter, the charging charger 120 is weakly switched to charge between the leading end and the trailing end, and the relative rotation angle between the rotating drum 110 and the charging charger 120 causes the rotating drum 110 to charge and adsorb the rear end portion of the print medium. When it becomes possible to perform the charging operation, the charging charger 120 is again switched to a strong state to perform charging driving.

Thus, since the leading and trailing ends of the print medium with respect to the rotating drum 110 are strongly charged and the space between the leading and trailing ends is weakly charged, the leading end of the print medium is reduced while reducing the overall charge amount.・ Rotating drum 110 at rear end
Can be reliably attracted to the peripheral surface of the print medium, and the amount of dust adhering can be reduced by enlarging the weakly charged area while ensuring the effect of preventing floating in the middle of the print medium.

Therefore, the maintenance interval for wiping dust and the like adhered to the peripheral surface of the rotary drum 110 and the tip end surface of the nozzle head 15 can be greatly extended,
It is possible to further improve the printing speed, and it is effective for a print medium having a larger size than the case of the first or second aspect of the present invention.

(Fourth Embodiment) In the fourth embodiment, the basic configuration and functions are the same as those of the first embodiment (FIGS. 1 and 2).
6 and the third embodiment (FIG. 5), but furthermore, as shown in FIG.
It is formed so as to be capable of electrostatically adsorbing strongly to zero and partially weakly electrifying and adhering between the front end portion and the rear end portion.

That is, when the relative rotation angle between the rotating drum 110 and the charging charger 120 reaches a timing at which the leading end portion of the print medium can be charged and adsorbed on the rotating drum 110, the charging charger 120 is strongly switched to charge. Drive.

Thereafter, the operation of stopping (OFF) and driving (ON) the charging charger 120 again is repeated. During this period, the charging charger 120 is driven by weakly switching the charging.

Rotary Drum 110 and Charger 12
When the relative rotation angle with respect to 0 reaches the timing at which the leading end portion of the print medium can be charged and attracted to the rotating drum 110, the charging charger 120 is strongly switched to perform charging driving.

In this way, the leading and trailing ends of the print medium with respect to the rotating drum 110 can be strongly charged, and the portion between the leading and trailing ends can be weakly charged and the rotating drum 110 can be partially charged. As compared with the third embodiment, the leading and trailing ends of the print medium can be reliably attracted to the peripheral surface of the rotary drum while the overall charge amount is significantly reduced, and the print medium floats in the middle. The dust adhesion amount can be reduced by greatly expanding the weakly charged region while ensuring the prevention effect.

[0057]

According to the first aspect of the present invention, the charging charger can be switched between charging and stopping by adjusting the timing to the rotation angle of the rotating drum, and the leading and trailing end portions of the printing medium can be moved to the rotating drum. Since it is an electrostatic attraction type drum printer formed so that it can be electroadsorbed and the part between the leading end and the trailing end can be charged and adsorbed, the leading and trailing ends of the printing medium can be It is possible to reliably adsorb the dust on the peripheral surface of the rotating drum, and to reduce the amount of dust attached by expanding the non-charged area while ensuring the effect of preventing floating in the middle of the print medium. Accordingly, the maintenance interval for wiping dust and the like adhered to the peripheral surface of the rotary drum and the tip end surface of the nozzle head can be greatly extended, so that the printing speed can be further improved.

According to the second aspect of the present invention, the charging drive can be switched between charging and stopping by adjusting the timing of the charging charger to the rotation angle of the rotating drum, and the leading end and the trailing end of the printing medium can be moved to the rotating drum. Since the electrostatic adsorption type drum printer is formed so that it can be electroadsorbed, the leading and trailing ends of the printing medium can be reliably attracted to the peripheral surface of the rotating drum while greatly reducing the overall charge amount. The effect of preventing floating in the middle of the print medium can be ensured while reducing the amount of dust attached by greatly expanding the charging area. In particular, claim 1
Since the intermediate portion of the print medium is not charged as compared with the case of the invention of the third aspect, it is effective for a print medium having a short size in the rotation direction of the rotating drum.

According to the third aspect of the present invention, the charging charger is formed so as to be switchable between charging drive / stop and charging intensity depending on the timing of the rotation angle of the rotating drum, and to switch the charging medium strength. And the rear end of the drum are electrostatically attracted to the rotating drum, and the front and rear ends are weakly charged and attracted. In addition, the leading and trailing ends of the print medium can be reliably attracted to the peripheral surface of the rotating drum, and the effect of preventing floating in the middle of the print medium is reduced, while reducing the amount of dust attached by expanding the weakly charged area. be able to. Therefore, the maintenance interval for wiping dust and the like adhered to the peripheral surface of the rotating drum and the tip surface of the nozzle head can be significantly extended,
It is possible to further improve the printing speed, and it is effective for a print medium having a larger size than the case of the first or second aspect of the present invention.

Further, according to the invention of claim 4, the charging charger is formed so as to be capable of switching between charging drive / stopping and switching between charging intensity and weakness in accordance with the timing of the rotation angle of the rotary drum, and the leading end of the printing medium. An electrostatic attraction type drum printer which is formed so as to be capable of strongly electrostatically adsorbing a rotating drum and a rear end portion thereof, and being capable of partially weakly electrifying and adhering between a front end portion and a rear end portion. The leading and trailing ends of the print medium can be reliably attracted to the peripheral surface of the rotating drum while greatly reducing the overall charge amount as compared with the case of the present invention, and the effect of preventing floating in the middle of the print medium can be achieved. The dust adhesion amount can be reduced by greatly expanding the weakly charged area while securing the area.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a first embodiment of the present invention.

FIG. 2 is a view for explaining a holding state of a rotary drum and a print medium.

FIG. 3 is a timing chart for explaining a driving / stopping operation of the charging charger.

FIG. 4 is a timing chart for explaining a driving / stopping operation of a charging charger according to a second embodiment of the present invention.

FIG. 5 is a timing chart for explaining a driving / stopping operation of a charging charger according to a third embodiment of the present invention.

FIG. 6 is a timing chart for explaining a driving / stopping operation of a charging charger according to a fourth embodiment of the present invention.

FIG. 7 is a diagram for explaining a previously proposed electrostatic adsorption type drum printer.

FIG. 8 is a view for explaining a holding state of a rotary drum and a print medium.

[Explanation of symbols]

 Reference Signs List 5 Image processing unit 7 Engine controller 10 Nozzle unit 41 Tip chuck mechanism 42 Trailing chuck mechanism 110 Rotary drum 120 Charging charger 130 Rotation angle detecting means 131 Detector 132 Tip detection target 133 Rear detection target

Claims (4)

[Claims] An image forming apparatus comprising: a rotary drum configured to hold a print medium by using an electrostatic attraction force applied by using a charging charger and to rotate and transfer the held print medium by using rotation of the rotary drum; In an electrostatic attraction type drum printer formed so as to be able to print by driving a head on a rotating print medium, it is possible to switch charging drive / stop by adjusting the timing of the charging charger to the rotation angle of the rotating drum. And forming a front end portion and a rear end portion of the print medium with respect to the rotating drum so as to be electrostatically adsorbable to the rotating drum, and to allow a portion between the leading end portion and the rear end portion to be electrically charged and adsorbed to the rotating drum. The formed electrostatic adsorption drum printer. 2. A print medium is formed to be capable of holding a print medium by utilizing an electrostatic attraction force applied to the rotary drum by using a charging charger, and to be capable of rotating and transporting the held print medium by using the rotation of the rotary drum. In an electrostatic attraction type drum printer formed so as to be able to print by driving a head on a rotating print medium, it is possible to switch charging drive / stop by adjusting the timing of the charging charger to the rotation angle of the rotating drum. An electrostatic attraction type drum printer formed and formed so that a front end portion and a rear end portion of the print medium with respect to the rotating drum can be electrostatically attracted to the rotating drum. 3. A printing medium is formed to be capable of holding a printing medium by utilizing electrostatic attraction force applied to the rotating drum by using a charging charger and to be capable of rotating and transporting the held printing medium by utilizing rotation of the rotating drum. An electrostatic attraction type drum printer formed so as to be capable of printing by driving a head on a printing medium being rotated, wherein the charging charger can be switched between charging driving and stopping by adjusting the timing to the rotation angle of the rotating drum; In addition to forming the charging strength to be switchable, the leading end and the trailing end of the printing medium with respect to the rotating drum can be strongly electrostatically attracted to the rotating drum, and the gap between the leading end and the trailing end is located on the rotating drum. An electrostatic adsorption type drum printer that is weakly charged and adsorbable. 4. A printing medium which is capable of holding a printing medium by utilizing an electrostatic attraction force applied to the rotating drum by using a charging charger and capable of rotating and transporting the held printing medium by utilizing the rotation of the rotating drum. An electrostatic attraction type drum printer formed so as to be capable of printing by driving a head on a printing medium being rotated, wherein the charging charger can be switched between charging driving and stopping by adjusting the timing to the rotation angle of the rotating drum; In addition to forming the charging strength to be switchable, the leading end and the trailing end of the printing medium with respect to the rotating drum can be strongly electrostatically attracted to the rotating drum, and the gap between the leading end and the trailing end is located on the rotating drum. An electrostatic adsorption type drum printer that is partially weakly charged and adsorbable.