JP2522954Y2 - Charger structure of plate making machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charger structure of a plate making machine for producing a master on which an image is formed for printing, and more particularly, to a charging area of a back side charger at both right and left ends in the traveling direction of the master. The present invention relates to a charger structure of a plate making machine that reduces the charged area of a side charger and improves plate deviation after development.

[0002]

2. Description of the Related Art Conventionally, this type of plate making machine is used for producing a master used in a printing press.
A sheet-like zinc oxide master paper (abbreviated as ZnO master paper) or aluminum is operated by switching a mode selection switch provided on the main body of the plate making machine according to various conditions such as a printing form, the number of prints, and a paper feeding method. Paper feed system, lens aperture of exposure optical system, set temperature of panel heater in fixing process, and corresponding to selected master such as organic photoreceptor master plate (abbreviated as OPC master plate) using plate as substrate The pressing force of the pressing roller is automatically set to an appropriate condition. Then, the surface of the master is fed while the master fed out from the cassette or the manual sheet feeding unit passes between the transport rollers while moving on the guide plate, and passes through chargers arranged vertically. The master charged by the charger is formed into a latent image on a document image on an exposure stage, and then taken out to a discharge tray through a development and fixing process.

[0003]

However, in the conventional charger structure of a plate making machine, for example, as shown in FIG.
The illumination lamp is illuminated on the original G in the range S, and the exposure area S _{0 on} the surface of the master X is closer to the image area S _{1 of the} original G.
Although the charging area E ₀ of the charger is set to be wider, when the master X charged and exposed by the charger having such a structure is developed, the charging area E _{0 and} the charging area E ₀ deviate from the charging area E ₀ . There is a problem that a step occurs in the toner density at the boundary portions on both sides of the surface of the master X, and the step becomes clearly visible, and the plate deviation of the image-formed master becomes worse.

An object of the present invention is to solve the above-mentioned problem in the structure of the charger of the conventional plate making machine.
An object of the present invention is to provide a charging device of a plate making machine capable of eliminating a toner density step generated in a non-image portion of a master that is out of an image area.

[0005]

In order to achieve this object, the present invention charges the cut master, sends it to an exposure stage, exposes the original image to the master, and then forms the exposed latent image on the master. A plate making machine for developing and fixing, wherein the charged area of the back side charger at both left and right ends in the traveling direction of the master is smaller than the charged area of the front side charger.

[0006]

In order to charge the printing master before the exposure of the original image on the master for printing by using the charger structure of the plate making machine according to the present invention based on such a configuration, first, the charging is carried out on the plate making machine main body. By operating the mode selection switch
The paper feeding method, the lens aperture of the exposure optical system, the set temperature of the panel heater in the fixing process, and the pressing force of the pressure roller automatically switch to the appropriate conditions according to the selected master such as ZnO master paper or OPC master plate. Is done. Then, a predetermined charge is applied to the surface of the master while the master fed out from the cassette or the manual sheet feeding unit passes between the transport rollers and passes through chargers arranged vertically. At this time, since the charged area of the back side charger at the left and right ends in the traveling direction of the master is smaller than the charged area of the front side charger, the charge amount at the boundary of the image area is reduced. There is no step in the toner density at the same boundary after development, and the plate deviation after development is good.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is an overall longitudinal sectional view of a plate making machine showing an embodiment according to the present invention. A plate feeding machine main body 1 is provided with a supply side conveyance system. An insertion port 1a is formed. The cassette 2 includes, for example, a ZnO master paper X cut to a predetermined size.
With ₁ is a large number of sheets accommodated, manual paper feed portion 2a thick OPC master plate X ₂ is inserted into each piece is provided on the upper surface of the cassette 2 the upper lid. An operation panel for controlling various operation states is provided at a predetermined position of the plate making machine main body 1.
This part, or the cassette feeding type ZnO master paper X ₁ is used, or a mode selection switch for switching on or manual feed system OPC master plate X ₂ is used is provided by the properties of the master X.

Above the leading end of the cassette 2 on the insertion side, a paper feed roller 3 for feeding out ZnO master paper X1 in the cassette 2 _one by one is installed so as to be vertically movable in the direction of arrow A. Reference numeral 3 denotes a manual paper feed unit 2a in which a manual paper feed system is selected by operating a mode selection switch.
If the OPC master plate X ₂ is inserted from the cam 4 of the roller raised position locking means 4 (not shown)
a, it is configured to be locked at the raised position by the arm 4b and the like. Further, when the cassette paper feeding system is selected by operating the mode selection switch, the lock of the roller raising position locking means 4 is released, and the cam 4a rotates to lower the paper feeding roller 3 to the leading end of the cassette 2. to allow the feeding of ZnO master paper X ₁ in the cassette 2.

In front of the cassette 2, a charger 7 is arranged following a pair of upper and lower transport rollers 6, and a master X fed from the cassette 2 or the manual paper feed unit 2a is
The surface of the master X is charged while passing on the charger 7 while passing between the transport rollers 6 while moving on the guide plate 5a. As shown in FIGS. 2 and 3, the charger 7 includes a pair of upper and lower front-side chargers 7a and a back-side charger 7b having a charge line 7g for charging the front side while the master X passes. I have. Then, an insulator 7e to limit the charged surface 7c of the surface-side charger 7a, and step d _o is formed to weaken the charged between the insulator 7f to limit the charged surface 7d of the rear charger 7b, the and the step d _o the strong part d _m of charge, the charge cut parts to the left and right end portions in the traveling direction of the master X d _s
Is provided to reduce the charge amount at the boundary of the image area, so that there is no step in the toner density at the same boundary after development, and the plate deviation after development is improved.

The master X, which has been charged, is placed on the guide plate 5
b and is transferred to the exposure stage 8 while
For exposure on the exposure stage 8 and maintenance management, a lamp house 11 having a document table 10 is installed above the plate making machine body 1 facing the exposure stage 8. The lamp house 11 is hinged on the left side base portion of FIG. 1 to the plate making machine main body 1 with a hinge 12 and a gas stay 1 provided on a side between the lamp house 11 and the plate making machine main body 1.
3 so that it can be opened and closed in the direction of arrow B,
When the lamp house 11 is in the normal state shown by the solid line, it can be switched so that it can coincide with the position above the exposure stage 8. When the lock device (not shown) is released, the lamp house 11 is moved to the hinge 12 and the gas stay 1.
3, the lamp house 11 is held at the open position indicated by the virtual line, and the lamp house 11 can be returned to the normal state indicated by the solid line by strongly pressing the lamp house 11 downward. Can be checked.

On the upper surface of the lamp house 11, a document table 10 moves in the direction of arrow C in FIG.
Then, the document set on the document table 10 is irradiated by the illumination lamp 14 in the lamp house 11 and moves on the exposure plate 20 of the exposure stage 8 via the reflection mirrors 15 and 16, the projection lens 18 and the reflection mirror 19. An image is formed on the surface of the master X. Here, the lens aperture 17 is intended to be automatically switched by operation of the mode selection switch, for example, in the case of ZnO master paper X ₁ by the cassette feeding will reduce the lens aperture, OPC master plate by manual feeding equal to the lens aperture to the large in the case of X _2, which is to be switched by the characteristics of the master. Further, the movement of the document table 10 and the movement of the master X transported by the pair of upper and lower transport rollers 21 and 22 installed on the entrance side and the exit side of the exposure stage 8 are synchronized so as to be at a constant speed. The master X, which has been exposed and formed an image, moves on the guide plate 5c to the next developing step 23 via a pair of upper and lower direction changing rollers 24, 25 and transport rollers 26, 27. Be transported.

The direction changing roller 24 for feeding the master X to the developing step 23 has a predetermined roller width and is divided into a plurality of pieces on a shaft, as shown in FIG. It is rotatably mounted and the lower drive shaft 2
An interval m of several millimeters is maintained between the roller 5a and the rod-shaped roller 25 mounted on the roller 5a. Further, a pair of upper and lower transport rollers 26, 2 provided following the direction changing roller 24.
Reference numeral 7 is attached to a rotatable shaft 26a and a drive shaft 27a, respectively, and is divided into a plurality so that the upper conveying roller 26 is located between the direction changing rollers 24 on the shaft 26a. Then, the tip of the master X, which has moved on the guide plate 5c, abuts on the direction changing roller 24, but rotates in the direction in which the rotatable direction changing roller 24 is pressed by the master X, thereby moving the master X in FIG. (A), (b) and (c) as shown in the state of FIG.
By the driving force of 7a, the sheet is nipped between the conveying rollers 26 and 27 and fed out. Further, while the master X moves on the guide plate 5 e in the developing process 23, the electrostatic latent image is developed by the developer spray sprayed from the spray head 29 of the developing device 28.

The master X developed by the developing device 28 is passed through the next squeezing roller 30 and suction roller 31 to remove residual liquid for development, and is transferred to a fixing process 32.
In the fixing process 32, the master X is controlled by the panel heater 33.
Is heated to a predetermined temperature while moving at a constant speed, and the whole is uniformly dried by an electric fan 34 installed above. Heater switching temperature of the panel heater 33 is different depending on the characteristics of the master X, especially in the case of OPC master plate X ₂ are by manual feeding mode, high heater switching temperature than ZnO master paper X ₁ by the cassette feeding system Therefore, the switching temperature of the panel heater 33 corresponding to the characteristics of the master X is automatically switched by the mode selection switch of the plate making machine main body 1. The master X dried by the panel heater 33 is pressed from above by pressing rollers 35a and 35b arranged in two rows to fix a document image on the front surface.
6 is taken out onto a paper discharge tray 37 installed outside the plate making machine main body 1 by the rotary feed motion 6.

[0015] In the above fixing step 32, the pressure roller 35a of the master X, To complete the fixing by crimping by 35b, the ZnO master paper X ₁ by cassette feeding, pressure roller 35a, 35b contact pressure only by is sufficient, in the case of OPC master plate X ₂ by manual feeding may crimping force can not uniform fixing missing. Therefore, as shown in FIG. 5, a pressing means 38 which can move up and down is provided above the pressing rollers 35a and 35b. The pressurizing means 38 includes a fixing weight 39 which contacts the pressing rollers 35a and 35b and presses the fixing weight 39 from above, a spring 42 for lifting the fixing weight 39, a link arm 40 for vertically moving the fixing weight 39, and the link arm 40. It is constituted by a solenoid 41 and the like which are rotated via a fixed fulcrum 40a. Then, the solenoid 41 only when the OPC master plate X ₂ at manual feeding by the mode selection switch of the plate making machine body 1 is selected is activated, fixing weights 3
9, the pressing rollers 35a and 35b are pressed from above to increase the pressing force.

On the other hand, the OPC master plate X ₂ on which an image has been formed by the plate making machine main body 1 is transferred to a post-processing device (not shown) to wash off the photosensitive layer in the non-image area of the OPC master plate X ₂ to obtain a desired image. Can be obtained. Here, the master X is the case of ZnO master paper X ₁ fed out by the cassette feeding method, plate making state by the plate making machine body 1, can be obtained directly printing image master.

The plate-making machine illustrated embodiment, configured as described above is because, print form, OPC by ZnO master paper X ₁ or the manual paper feeding method according cassette feeding method selected by various conditions such as the number of prints the master plate X _2, exposure and development of the original image are performed respectively through the process described below, it is possible to fabricate the imaged master for good quality printing. First, by operating a mode selection switch provided on the plate making machine main body 1 in accordance with the characteristics of the master X to be used,
The feeding method of the selected ZnO master paper X ₁ or OPC master plate X ₂ , the lens aperture 17 of the exposure optical system, the temperature of the panel heater 33 in the fixing process 32, the pressure of the press-contact rollers 35 a, 35 b, and the like are set to appropriate conditions. Automatically switched.

Then, when the start switch is pressed after the mode selection switch of the plate making machine main body 1 is selected, the selected master X is fed out by the cassette paper feeding system or the manual paper feeding system, and the charger 7 is charged. After that, it is transferred to the exposure stage 8. Master X is exposure stage 8
Reaches the sensor 9 installed in front of the transport roller 21 on the entrance side of the document table, and detects the document table 10 at a set timing after the detection.
Starts synchronous movement, and the original image is illuminated by the illumination lamp 14 in the lamp house 11, and the reflection mirrors 15, 16,
Exposure plate 20 through projection lens 18 and reflection mirror 19
The image is formed on the upper master X.

The master X that has passed through the exposure stage 8
The developer is sent to the developing process 23 via the direction changing roller 24 and the conveying rollers 26 and 27, and is supplied to the spray head 2 of the developing device 28.
The electrostatic latent image is developed by the developer spray sprayed from the nozzle 9. Then, the developed master X is subjected to a fixing process 3
2 is heated and dried by the panel heater 33 and the electric fan 34, and the fixing is completed by the pressing force of the pressing rollers 35a and 35b.
Taken out on top. As described above, by switching the mode selection switch before the start of the plate making machine main body 1, the roller raising position locking means 4 for selecting the operation of the paper feed roller 3,
The characteristics of the master X to be used, such as the lens aperture 17 of the exposure optical system that forms the original image on the master X on the exposure plate 20, the set temperature of the panel heater 33 in the fixing process 32, and the pressing force of the pressing rollers 35 a and 35 b, Since the condition is automatically switched to the corresponding condition, even a master having different characteristics can be manufactured by a single plate making machine.

[0020]

As is apparent from the above description, according to the charger structure of the plate making machine according to the present invention, the charged area of the back side charger at both left and right ends in the traveling direction of the master is larger than the charged area of the front side charger. Is also reduced, the charge amount at the boundary of the image area is reduced, and no step is formed in the toner density at the same boundary after the development, and there is an effect that the plate deviation after the development can be improved.

[Brief description of the drawings]

FIG. 1 is an overall longitudinal sectional view of a plate making machine showing an embodiment according to the present invention.

FIG. 2 is a sectional view showing the structure of the charger according to the present invention;

FIG. 3 is a sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is an enlarged view showing details of a direction changing roller for sending a master to the developing process in FIG. 1;

FIG. 5 is an enlarged view showing details of a pressing unit in a fixing process of FIG. 1;

FIG. 6 is an explanatory diagram showing a relationship between an image area and a charged area by a conventional charger structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate making machine main body 2 Cassette 3 Paper feed roller 4 Locking means 7 Charger 7a Front side charger 7b Back side charger 7e, 7f Insulator 8 Exposure stage

Claims (1)

(57) [Scope of request for utility model registration] 1. A plate making machine for charging a cut master, sending the charged master to an exposure stage, exposing a document image to the master, and developing and fixing the exposed latent image. A charging structure for a plate making machine, wherein the charging area of the back-side charger at both left and right ends is smaller than the charging area of the front-side charger.