JP3518448B2 - Wet development equipment for plate making machines - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device for developing a latent image on a photosensitive sheet, and more particularly to a wet developing device for a plate making machine for developing an electrostatic latent image on the surface of a master sheet which is a photosensitive sheet.

[0002]

BACKGROUND ART As is well known, in a wet developing apparatus of a plate making machine, after developing an electrostatic latent image of a master sheet with a developing solution, the master sheet is passed through a pair of squeezing rollers that are in rolling contact with each other to form a master sheet. After removing the attached excess developer, the developed image is fixed by the subsequent fixing and drying device.

That is, FIG. 6 shows a conventional squeezing roller used for such a purpose, in which the master sheet X developed by the rotational movement of the upper squeezing roller R1 and the lower squeezing roller R2, which are in rolling contact with each other, is While being fed in the direction of the arrow, the excess developer adhering to the master sheet X is removed by the pressure applied between the upper squeezing roller R1 and the lower squeezing roller R2.

However, when such a squeezing roller is used, the upper squeezing roller R1 is strongly pressed against the surface of the master sheet X, so that part of the toner image on the surface of the master sheet X is laid on the peripheral surface of the upper squeezing roller R1. A so-called “offset phenomenon” occurs in which the transferred toner image A is transferred to the surface of the master sheet again at a constant interval P as the transferred toner image A is rotated, and the image quality of the surface of the master sheet X is deteriorated.

[0005]

In order to prevent such an "offset phenomenon", conventionally, an upper squeezing roller R1 is used.
The pressure applied between the lower squeeze roller R2 and
We are trying to increase the hardness of the rubber that composes the squeezing roller, but these measures have to sacrifice the squeezing effect of the developer from the master sheet X, so that we can prevent the "offset phenomenon" as we would like. I couldn't. The toner image transferred to the peripheral surface of the upper diaphragm roller R1 is also transferred to the peripheral surface of the lower diaphragm roller R2.
There is also a problem that the back surface of the master sheet X is soiled by the retransfer from the peripheral surface of 2.

In view of the problems of the conventional wet type developing apparatus of the plate making machine as described above, the object of the present invention is to keep the developing solution squeezing function of the squeezing roller sufficiently, while keeping the peripheral surface of the upper squeezing roller. This is to obtain a wet developing device of a plate making machine in which the transferred toner image is not transferred to the surface of the master sheet.

[0007]

To achieve this object, the present invention develops an electrostatic latent image on a master sheet while passing through a development pallet and places an upper squeeze roller and a lower squeeze roller positioned on the exit side. In a wet developing device of a plate making machine that squeezes the excess developer adhering to the master sheet by a rolling contact movement with an upper blade that can be engaged with and disengaged from the peripheral surface of the upper squeezing roller, and the peripheral surface of the same blade and the upper squeezing roller. And an injection pipe capable of ejecting the developing solution in a space between the upper blade and the upper crank, the intermediate bent portion of which is fixed to one end of a bell crank supported by a device fixing portion by a pivot shaft and the bell crank. An electromagnetic solenoid is coupled to the operating end of the injection pipe, the injection pipe is fixed to the bell crank, and the peripheral surface of the upper squeezing roller is formed by the developer from the injection pipe and the upper blade in the plate making process of a plate making machine. It proposes a wet development apparatus for plate-making machine for dissolving and removing the transfer image.

In the description of preferred embodiments of the present invention described below, 1) a lower blade is provided which can be engaged with and disengaged from the peripheral surface of the lower squeezing roller, and the lower blade is provided in the plate making process. 2) The lower blade is fixed to a support bracket which is rotatably supported by a device fixing portion about a pivot, and the support bracket is controlled by a linking wire suspended between an electromagnetic solenoid and the support bracket. The structure is explained.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 shows an overall cross section of a plate making machine according to the present invention, in which a first sheet feeding device 2A and a second sheet feeding device which can mount different sizes of master sheet rolls on a lower right portion of a machine body 1 capable of shielding external light. Paper device 2B
Is built in.

The first sheet feeding device 2A and the second sheet feeding device 2B include a detachable mounting drum 2a to which a master sheet roll can be attached, a feeding roller 2b for pulling out the leading end of the master sheet X, and the master sheet X. A cutter 2c and a paper feed roller 2d for cutting to a designated length are respectively provided, and the cut master sheet X is sent to the paper feed path 3 through the first path 3a and the second path 3b. A charging electrode 4 for charging the master sheet X is provided in the middle of the sheet feeding path 3, and the master sheet X passing through the charging electrode 4 is fed at the center of the upper part of the machine body 1 which is driven at a sub-scanning speed. It is supplied to the roll 5.

The surface of the master sheet X positioned on the feed roll 5 is beam-scanned by a laser scanning unit 6 with a document image, and after the original image is formed on the photosensitive surface of the master sheet X by the same scanning, a latent image is formed. The master sheet X is delivered to the wet developing device 7 in the left half of the machine body 1.

The wet developing device 7, which will be described later in detail, has a developing solution nozzle 13 for ejecting a developing solution onto a developing pallet 11 through which the master sheet X passes, and the developing device is inclined downward in the conveying direction of the master sheet X. A developer tank 15 for collecting the developer is located below the pallet 11. In addition, the wet developing device 7 has a developer pump 2 that sends a developer under pressure to a first injection pipe 19 and a second injection pipe 21, which will be described later.
Have three.

The master sheet X on which the original image has been developed is dried by the heating and fixing device 8 adjacent to the exit side of the wet developing device 7 to fix the toner image, and the discharge roller 9 provided on the upper left side of the machine body 1 is fixed. It is collected on the collecting tray 10 outside the machine body 1 by the discharging movement. Although not shown in the drawings, in order to detect the passage timing of the master sheet X, the developing unit entrance sensor S1 for detecting the leading edge of the master sheet X passing through the entrance of the wet developing device 7 is the master sheet passing through. A paper discharge sensor S2 for detecting the rear end of X is arranged at the paper discharge roller 9 position.

FIG. 2 shows the details of the wet developing device 7 described above, and the developing pallet 1 supported by the developing device frame 31.
A developing section entrance roller 33, which is rotationally driven in the direction of the arrow, is supported on the entrance side of 1. The master sheet X is taken into the developing pallet 11 by the feeding movement of these developing section entrance rollers 33. A developer nozzle 13 having a rectifying blade 35 extending in a direction perpendicular to the paper surface of FIG. 2 is located above the entrance of the developer pallet 11, and the developer sent under pressure from the first injection pipe 19 is the same. Developer nozzle 1
3 is ejected in a film form from the tip of the developing pallet 11 onto the surface of the developing pallet 11.
1, a horizontal support shaft 37 extending in the width direction is supported, and the horizontal support shaft 37 has a weight 3 that is naturally lowered by gravity.
9 is supported.

The entire surface of the developing pallet 11 is covered with a low friction net member 41 that guides the master sheet X, and the third jet pipe 43 located immediately below the developing solution nozzle 13 is provided on the inlet side of the developing pallet 11. Is positioned and the developing solution is supplied from the third injection pipe 43 to the lower surface side of the passing master sheet X. A developing electrode plate 45 is positioned above the outlet side of the developing pallet 11, and the developing electrode plate 45 guides the developing solution discharged from the master sheet X and the developing solution nozzle 13 to the outlet side of the developing pallet 11. The developer is dripped and collected from the end into the developer tank 15.

On the outlet side of the wet type developing device 7, a detachable upper blade 49 for cleaning the peripheral surface of the upper squeezing roller 47A.
Is provided. The upper blade 49 has an intermediate bent portion fixed to a driven end of a bell crank 53 supported by a pivot shaft 51. The operation end of the bell crank 53 is excited to move the upper blade 49 to the upper squeezing roller 47A. The first electromagnetic solenoid 55 which can be slidably contacted with the peripheral surface of is contacted. Further, a second injection pipe 21 for ejecting the developing solution into the space between the upper blade 49 and the upper squeezing roller 47A is fixed to an intermediate bent portion of the bell crank 53. The developer is pumped to the second jet pipe 21 from the developer pump 23 described above, but the second jet pipe 21 is fixed to the developing device frame 31 without being fixed to the bell crank 53. Therefore, the developer may be jetted into the space between the upper blade 49 and the upper aperture roller 47A.

Further, the lower blade 57 located below the developing pallet 11 is disengageably positioned so as to face the peripheral surface of the lower squeeze roller 47B which is in rolling contact with the upper squeeze roller 47A. The lower blade 57 is fixed to a supporting bracket 61 supported by the developing device frame 31 by a pivot 59, and is connected to a supporting wire 65 operated by a second electromagnetic solenoid 63. That is, the linking wire 65 having one end fixed to the operation end of the support bracket 61 that is rotated about the pivot 59.
Is guided to the second electromagnetic solenoid 63 at the lower right side of the wet type developing device 7 via the guide roller 67, and the tip of the lower blade 57 can be engaged with the peripheral surface of the lower squeezing roller 47B by the excitation of the second electromagnetic solenoid 63. . The second electromagnetic solenoid 63 that operates the lower blade 57 engages the lower blade 57 with the peripheral surface of the lower squeezing roller 47B in the developing process to keep the peripheral surface clean.

Returning to FIG. 1, the above-mentioned heat fixing device 8 receives the master sheet X developed from the wet developing device 7 and a fixing portion inlet roller 67 and a panel heater 69 for drying and fixing the toner image on the master sheet X. A drying fan 71 is provided above the panel heater 69 to blow dry air onto the surface of the master sheet X passing therethrough.

Next, the operation of each part of the plate making machine from the start of plate making to the end of plate making will be described with reference to the time chart shown in FIG. When the plate making start button is operated, the developing / fixing section motor and the developing section pump are activated, and immediately after this (after time T1), the first electromagnetic solenoid 55 and the second electromagnetic solenoid 63 are simultaneously excited, and the first electromagnetic The upper blade 49 and the lower blade 5 are moved by the solenoid 55 and the second electromagnetic solenoid 63 for a fixed time (time T2 and T3).
7 corresponds to the upper squeeze roller 47A and the lower squeeze roller 47
The peripheral surface of B is engaged, and these peripheral surfaces are cleaned by the upper blade 49 and the lower blade 57.

Thereafter, the first electromagnetic solenoid 55 and the second electromagnetic solenoid 63 are demagnetized, but when the exposure of the original image is finished and the master sheet X is detected by the developing section entrance sensor S1, the first electromagnetic solenoid is again detected. The solenoid 55 and the second electromagnetic solenoid 63 are excited, and the upper blade 49 and the lower blade 57 are engaged with the peripheral surfaces of the corresponding upper diaphragm roller 47A and lower diaphragm roller 47B. Of course, the peripheral surfaces of the upper diaphragm roller 47A and the lower diaphragm roller 47B are always cleaned by the engagement of the upper blade 49 and the lower blade 57 with the peripheral surfaces of the upper diaphragm roller 47A and the lower diaphragm roller 47B. Even if a toner image or the like is temporarily transferred to the peripheral surface of the sheet, these transferred toner images are removed during one rotation of the upper squeeze roller 47A and the lower squeeze roller 47B, and thus are transferred to the surface of the passing master sheet X. It will not be done. In the plate making process, the peripheral surface of the lower squeeze roller 47B is always cleaned by the lower blade 57, so that the upper squeeze roller 47A and the like are sewn to the lower squeeze roller 47B.
It is possible to obtain a master sheet X having no transfer stain on both the front surface and the back surface, since stains and the like transferred to the peripheral surface of the master sheet X are not transferred to the back surface of the master sheet X.

Further, at the time of development by the wet developing device 7, the developer injected from the first injection pipe 19 and the third injection pipe 43 is the master sheet X and the development pallet 1.
2 and 3, the upper blade 49 and the upper squeezing roller 4 are supplied to the surface of the upper surface of the sheet 1.
Since the developing solution also flows out from the second jetting pipe 21 into the space between the peripheral surface of 7A, the transferred image and the like attached to the circumferential surface of the upper aperture roller 47A by the developing solution from the second jetting pipe 21. As a result of the scraping action of the upper blade 49 and the dissolving action of the developer, the upper squeezing roller 47 is dissolved.
The peripheral surface of A is always kept in a normal state.

In the developing process described above, the drying fan 71 of the heat fixing device 8 is activated after a short time,
When the trailing edge of the master sheet X is detected by the sheet discharge sensor S2, the developing section pump is stopped and at the same time, the first electromagnetic solenoid 55 is demagnetized and the upper blade 49 is separated from the peripheral surface of the upper aperture roller 47A. At the same time, the outflow of the developer from the first injection pipe 19, the second injection pipe 21, and the third injection pipe 43 is stopped. After this, the lower squeeze roller 4
The lower blade 57, which has scraped off the excess developer adhering to 7B, is separated from the lower squeezing roller 47B by the demagnetization of the second electromagnetic solenoid 63, the drying fan 71 is also stopped, and the plate making process ends.

[0023]

As is apparent from the above description, according to the inventions of claims 1 and 2, the transferred toner image transferred to the upper squeezing roller is the developing solution from the upper blade and the second jet pipe. The transferred toner image is not transferred to the surface of the master sheet X because it is immediately removed by
Image quality deterioration due to transfer can be completely prevented. Also,
According to the third and fourth aspects of the present invention, not only transfer contamination on the front surface of the master sheet X but also contamination on the back surface of the master sheet X can be prevented, and the finished quality of the master sheet X can be improved.

[Brief description of drawings]

FIG. 1 is an overall sectional view of a plate making machine to which the present invention is applied.

FIG. 2 is a cross-sectional view of a wet developing device of the plate making machine.

FIG. 3 is an enlarged cross-sectional view of a main part of the wet developing device.

FIG. 4 is a perspective view of a main part of the wet developing apparatus.

FIG. 5 is a time chart of the plate making machine from the start of plate making to the end of plate making.

FIG. 6 is an explanatory diagram of toner image transfer by a conventional aperture roller.

[Explanation of symbols]

X master sheet X 7 Wet developing device 11 Development palette 13 Developer nozzle 19 First injection pipe 21 Second injection pipe 47A Upper aperture roller 47B Lower aperture roller 49 Upper blade 53 bell crank 55 First electromagnetic solenoid 57 Lower blade 61 Support bracket 63 Second electromagnetic solenoid 65 Link Wire

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-216290 (JP, A) Actual Development Sho 50-48638 (JP, U) Japanese Patent Publication 7-19099 (JP, B2) Actual Publication 7- 17080 (JP, Y2) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G03G 15/11 G03G 13/26

Claims (3)

(57) [Claims] 1. An electrostatic latent image on a master sheet is developed while passing through a developing pallet, and excess developer adhering to the master sheet is transferred by rolling movement of an upper squeeze roller and a lower squeeze roller positioned on the exit side. In a wet developing device of a squeezing plate making machine, an upper blade that can be engaged with and disengaged from a peripheral surface of the upper diaphragm roller, and an injection pipe that can eject a developing solution into a space between the blade and the peripheral surface of the upper diaphragm roller. The upper blade has an intermediate bent portion fixed to one end of a bell crank supported by a device fixing portion by a pivot and an electromagnetic solenoid is coupled to an operating end of the bell crank, and the injection pipe is A wet process of a plate making machine, which is fixed to a bell crank and dissolves and removes a transferred image of a peripheral surface of an upper squeezing roller by a developing solution from the jet pipe and the upper blade in a plate making process of the plate making machine. Development device. 2. A lower blade detachable from the peripheral surface of the lower squeezing roller is provided, and the lower blade is joined to the peripheral surface of the lower squeezing roller in a plate making process. Wet developing device of plate making machine. 3. The lower blade is fixed to a support bracket rotatably supported on a device fixing portion by a pivot, and the support bracket is controlled by a connecting wire hung between an electromagnetic solenoid. The wet developing device for a plate making machine according to claim 3.