JPH0624845Y2 - Fixing device for wet electrophotographic plate making machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a fixing device for a wet photolithography machine.

[Conventional technology]

In an electrophotographic copying machine or an electrophotographic plate making machine, various devices have been devised for fixing plain paper or photosensitive paper after development.
Among them, the heat roller method most widely used in electronic copying machines and the like passes the copy paper 20 between a pair of fixing rollers composed of a metal roller 22 having a heat source 21 and a rubber roller 23, as shown in FIG. I am trying to let you.
The metal roller 22 and the rubber roller 23 are arranged so as to be pressed so as to form the nip width D, and the toner image is fixed on the copy paper 20 by the heat from the heat source 21 between the rollers 22 and 23. Therefore, since this nip width D is a part of the cylinder, the heating time cannot be set so long.

By the way, in a fixing device for a photosensitive paper (photoconductive photosensitive paper) of an electronic plate making machine which is a plate material utilizing hydrophilicity and lipophilicity of water and oil (ink), when the photosensitive paper is printed, Therefore, it is necessary to withstand the printing durability of thousands and tens of thousands of sheets under the mixed adhesion state of water and ink while receiving a cylinder pressure of several kg at high speed, so the toner on the photosensitive paper must be firmly fixed. I have to. In addition to this, photosensitive paper is usually 0.
10 to 0.30 mm thick (1.5 to 3 times that of plain paper),
Since the base paper has a resin coating on the back surface for waterproofing and the base paper itself is dense, it has a large heat capacity, and therefore it is necessary to further cooperate with heating. In addition, the base paper itself of the photosensitive paper is the base when printing durability of 2000 to 3000 sheets or less is sufficient, so the air layer inside the paper expands when the heating panel temperature at fixing is 150 ° C or more. However, since this air cannot escape to the outside due to the coating on the back surface of the base paper, a so-called puncture phenomenon occurs, and therefore the temperature control of the heating panel must be set to a temperature lower than that.

Considering these conditions, in the above-described heat roller system, the nip width D is small, so that the heating time is short and sufficient fixing cannot be provided. Further, slowing down the rotation speed of the heat roller in order to secure the heating time means slowing down the plate making speed, and raising the heating temperature of the heat roller is dangerous because it causes the above-mentioned puncture phenomenon.

In order to solve such a problem, as shown in FIG. 5, in the electronic copying machine, the copy paper 20 is placed on the heating panel 2.
5 and the copy paper 20 from above the copy paper 20
There is proposed a fixing device provided with a copy paper pressing roller 26 that rotates at the same speed as the above-mentioned conveyance speed (see Japanese Patent Laid-Open No. 4883883). The copy paper pressing roller 26 has a structure in which a linear substance is radially implanted in the roller surface in the normal direction of the roller.

[Problems to be solved by the invention]

In the fixing device of the type shown in FIG. 5, since the positional relationship between the heating panel 25 and the paper pressing roller 26 is constant, the advancing copy paper 20 is mechanically positioned by the rotating roller 26 to the heating panel. Pressed on 25,
This pressing force cannot be managed unless the positional relationship between the heating panel 25 and the paper pressing roller 26 is adjusted strictly. Even if the pressing force of the copy paper 20 against the heating panel 25 is strictly adjusted, the pressing force is exerted through the elasticity of the polyester fiber on the surface of the paper pressing roller 26, and therefore the elasticity of the roller itself or The elasticity of this fiber changes with time, and it is difficult to keep these changes constant.

Further, in the wet electrophotographic plate making machine, as described above, the thickness of the photosensitive paper is usually 0.10 to 0.30 mm depending on the application of the small plate, the medium plate and the large plate.
Range (the cylinder pressure of the printing press increases as the printing plate becomes larger, and the paper thickness tends to become thicker because printing durability is required), so the pressing force will differ due to this difference in thickness. .

Therefore, if this system is adopted in the fixing unit of an electrophotographic plate making machine, a jam of the photosensitive paper or uneven fixing is likely to occur. That is, the pressing force is not accurately controlled, and when the pressing force is large, the developed image on the photosensitive paper is peeled or disturbed. By the way, it was confirmed by experiments that when a wet developer is used, an unfixed image can peel off when a force of 35 g or more per 100 mm acts from above (the image reattaches to the upper photosensitive paper pressing roller). ing. That is, width 400 mm
It means that no more than 100g of force can be applied from above with the photosensitive paper.

On the other hand, if the pressing force is less than 15 g per 100 mm, if the advancing photosensitive paper has a warp in the width direction, the function of pressing the photosensitive paper against the heating panel from above and correcting the warp is weakened. The photosensitive paper floats on the heating panel, causing uneven fixing. Generally, electrophotographic platemaking machines allow flatness of the photosensitive paper of 5 mm or less, and in the experiment, a photosensitive paper having a thickness of 0.2 mm and a warp of 5 mm was passed between the heating panel and the paper pressing roller. In this case, when the pressing force is 10 g per 100 mm, the fixing temperature of 60 ° C. was obtained in the part where the photosensitive paper was in close contact with the heating panel, whereas the fixing temperature was 50 ° C. in the part where the floating occurred. There was a difference in printing.

Also, from the perspective of jamming the photosensitive paper, the heating panel 2
At the position of the paper pressing roller 26 on the sheet 5, the pressing force increases the frictional force between the back surface of the photosensitive paper and the upper surface of the heating panel, so that the progress of the photosensitive paper is hindered and a jam easily occurs. However, in this method, since there is no gap between the paper pressing roller and the heating panel, the photosensitive paper is easily bent in the traveling direction, and it is difficult to avoid the occurrence of jam.

In view of the above points, the present invention, in a wet electrophotographic plate making machine, efficiently performs sufficient heating without damaging the developed image regardless of the paper thickness of the photosensitive paper, and causes jamming. The present invention intends to provide a fixing device with less charge.

[Means for solving problems]

According to the present invention, the above-mentioned problems are caused in a fixing device of a wet electrophotographic plate making machine by suspending a heating panel with a spring around one end thereof as a rotation center and pressing a pressure roller on the heating panel at a predetermined pressure. It is solved by pressing and. That is, the structure of the present invention comprises a heating panel,
In a fixing device of a wet electrophotographic plate making machine for heating and fixing a wet-developed image, which comprises a pressure rotating roller which is on the surface of the heating panel and rotates at the same speed as the conveying speed of the photosensitive paper, The heating panel has a rotation fulcrum on its photosensitive paper carry-in side, and the photosensitive paper carry-out side is suspended under a predetermined tension by a spring, and the heating panel comes into contact with the pressure rotation roller at a predetermined pressure, Further, a fixing roller that is pressed against the heating panel by its own weight is provided downstream of the pressure rotation roller.

[Action]

In the present invention having the above structure, the heating panel can freely rotate about its one end as a fulcrum, and a constant tension is always applied by the spring.
Even if the thickness of the photosensitive paper changes, the pressing force of the heating panel against the photosensitive paper is kept constant. If the photosensitive paper is warped, the heating panel can be moved downward with a weak force, so that the progress of the photosensitive paper is not hindered and the possibility of jamming is eliminated.
Even if the undried viscous developer adheres to the back surface of the photosensitive paper and the friction between the heating panel and the heating panel increases, the pressing force of the heating panel is weak, and the photosensitive paper catches in this area and causes a jam. Prevent that.

Further, the fixing roller downstream of the pressure rotation roller presses the photosensitive paper on the heating panel only by its own weight, the nip width can be widened, and the fixing is efficiently performed.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. Referring to FIG. 1, the liquid-developed photosensitive paper 1 is sent out between a pair of upper and lower squeezing rollers 2 and 3, and passes over an upper surface of a heating panel 5 located next. At this time, the toner image surface of the photosensitive paper 1 is dried to some extent by the air blow 6 from the drying fan to remove the excess solvent adhering to the photosensitive paper 1.

The heating panel 5 has a rotary shaft 15 at one end on the photosensitive paper carry-in side.
Is supported with respect to the aircraft so that it can rotate about
The ends of the photosensitive paper carry-out side have tension springs 8 on both sides.
Is attached at one end thereof and is suspended by the tension spring 8. The tension of the tension spring 8 causes peeling of an image if the pressing force against the photosensitive paper is too large, and if the pressure is too small, uneven fixing due to the floating of the photosensitive paper and the heating panel occurs. Is. Therefore, the spring mounting plate 10 to which the other end of the spring 8 is mounted is
It is adjusted in advance so that a predetermined tension can be obtained by adjusting its mounting position with respect to the machine body.

A pressure rotation roller 7 that rotates at the same speed as the conveyed photosensitive paper 1 is disposed on the upper surface of the heating panel 5, and the photosensitive paper 1 is brought into close contact with the upper surface of the heating panel 5 by the rotating roller 7 to perform main heating. In response to this, the main fixing is done.
As shown in FIG. 2, a heat-resistant rayon synthetic fiber cloth is spirally wound around the surface of the pressure rotation roller 7 so as to absorb the developing solution. The parallel direction of the synthetic fibers is taken into consideration so as not to damage the photosensitive paper by arranging them in the forward direction of the rotation direction, as shown in detail in FIG. In addition, a heat-resistant adhesive is used for wrapping and is wound in a spiral shape so as to have strength of the adhesive. Heating panel 5
Is pulled upward by the tension spring 8 as described above, a desired constant weak pressure is always applied between the pressure spring 7 and the pressure rotary roller 7 rotating on the fixed rotary shaft.
Therefore, the photosensitive paper 1 always has a predetermined weak pressing force 9 (Fig. 1).
It is brought into close contact with the upper surface of the heating panel 5. In this embodiment, the force of 20 g per 100 mm of the photosensitive paper is set to work, and the width of the heating panel 5 is 450 mm, so that the total force of 90 g ± 5 g is set to work. As the spring tension of the tension spring 8, it is necessary to add the own weight of the assembly such as the heating panel 5.

A fixing roller 11 is arranged on the downstream side of the pressure rotation roller 7. This fixing roller 11 is constructed by winding a heat-resistant rayon-based synthetic fiber cloth on the surface of a thin-walled aluminum cored bar cylinder, like the pressure roller 7, to make it lightweight. In order to mount the fixing roller 11 above the heating panel 5, the support shaft fixing plates 12 are provided on both sides of the end of the heating panel 5, and the fixing plate 12 is provided with the groove 12a whose upper side is opened.
The supporting shaft 13 is inserted into and supported by the groove 12a so that the fixing roller 11 is placed on the upper surface of the heating panel 5 and the heating panel 5 is pressed by its own weight. That is, since the inner diameter 14 of the fixing roller 11 is set sufficiently larger than the outer diameter of the roller supporting shaft 13 and the weight of the roller supporting shaft 13 is supported by the fixed plate 12, the upper surface of the heating panel 5 is Only the pressing force due to the weight of the fixing roller 11 is applied.

The reason why the fixing roller 11 is used is as follows. That is, since the photosensitive paper 1 is sufficiently brought into close contact with the upper surface of the heating panel 5 and heated by the pressing force 9 by the spring 8 until reaching the fixing roller 11, the image on the photosensitive paper 1 is not peeled. It is strong. Therefore, at the position of the fixing roller 11, the image is not peeled off even if the fixing roller 11 having a certain weight is pressed by its own weight.
In addition, peeling of the image does not occur even if the fixing roller 11 is rotated by the conveying force of the photosensitive paper 1 without being forcibly rotated.

Further, as shown in FIG. 2, the heating panel 5 is heated in order to prevent an increase in the frictional force between the back surface of the photosensitive paper 1 and the upper surface of the heating panel 5 caused by the pressing force of the pressure rotation roller 7 and the fixing roller 11. Of the upper surface of the panel 5, the pressure rotation roller 7
The portion 5a from the fixing roller 11 to the fixing roller 11 is subjected to a treatment such that the friction coefficient is reduced, for example, a fluororesin coating. By reducing the frictional force, the photosensitive paper 1 can be conveyed without delaying the conveying speed, and damage to the image can be prevented. Further, in a portion up to the pressure rotation roller 7 on the upper surface of the heating panel 5, that is, in a portion where a vertical force is not exerted between the advancing photosensitive paper 1 and the upper surface of the heating panel 5 and a frictional force is small, Rather, for the purpose of scraping off the excess developer adhering to the back surface of the photosensitive paper by the upper surface of the heating panel 5, a non-processed portion having a large friction coefficient, that is, a rough surface state and conduction in this embodiment. The efficient aluminum alloy portion 5b is left.

Since the heating panel 5 is suspended by the spring 8 as described above, the heating panel 5 can be rotated from the solid line position to the chain line position as shown in FIG. Can be easily cleaned from above. More importantly, the heating panel 5
Since it can freely rotate around the rotation fulcrum 15 and a constant force is always applied by the spring 8, the thickness of the photosensitive paper 1 used is between 0.1 mm and 0.3 mm as described above. Even if it changes, the same pressing force 9 is obtained. Further, even when the leading end of the photosensitive paper 1 cannot be smoothly introduced between the pressure rotation roller 7 and the heating panel 5 due to warping of the photosensitive paper, the heating panel 5 can be moved downward with a weak force,
Does not cause a jam. Further, at this position, since the adhering after-development of the back surface of the photosensitive paper is not sufficiently dried and has a large viscosity, jam of the fixing portion is most likely to occur at this position. However, in this embodiment, even if the coefficient of friction between the back surface of the photosensitive paper and the upper surface of the heating panel is increased, the vertical force 9 is set to be weak, so that it is unlikely to cause a jam.

In this way, the photosensitive paper 1 which is brought into close contact with the heating panel 5 without being damaged by the image further advances and reaches the fixing roller 11.

Since the photosensitive paper 1 has already been conveyed in close contact with the upper surface of the heating panel 5 by the pressure rotation roller 7, it is unlikely that the photosensitive paper will warp, and the fixing roller 11 and the upper surface of the heating panel 5 can be smoothly moved. Jam of the photosensitive paper 1 is unlikely to occur because it enters during the interval. In addition, the developer adhering to the back surface of the photosensitive paper
Since the photosensitive paper 1 is conveyed in close contact with the upper surface of the heating panel 5 up to the fixing roller 11, most of it has already been scraped off by the upper surface of the heating panel 5, and there is little risk of jamming.

Since the photosensitive paper 1 is brought into close contact with the upper surface of the heating panel 5 between the pressure rotation roller 7 and the fixing roller 11 as described above,
The nip width A (see FIG. 2) is sufficiently longer than the conventional nip width D shown in FIG. 4, so that the fixing can be performed efficiently.

Since the fixing efficiency is good as described above, in this embodiment, sufficient fixing can be performed even under the condition that the control temperature of the heating panel 5 is 120 ° C. or lower. Therefore, the puncture of the photosensitive paper 1 as described above can be prevented, and since the control temperature is low, the adverse effect of heat is less likely to occur and the power consumption can be improved.

The photosensitive paper 1 on which the fixing is completed is ejected by the paper ejection roller 16.

[Effect of device]

As described above, according to the present invention, the pressing force between the heating panel and the pressure rotating roller arranged on the upper surface of the heating panel can be set to a desired pressure and can be maintained at an accurate pressing force. Regardless of the plate thickness, the image surface is not damaged at all, the occurrence of jam can be prevented, and good image fixing can be performed.

Further, a sufficient nip width can be secured between the pressure rotation roller and the fixing roller, and efficient fixing is achieved.

Furthermore, since the fixing roller presses the photosensitive paper only by its own weight,
The photosensitive paper is not pressed against the heating panel with an unnecessarily high pressure, is not affected by the thickness of the photosensitive paper, jams are less likely to occur, and stable fixing can be performed.

[Brief description of drawings]

FIG. 1 is an overall front view of an embodiment of the present invention, FIG. 2 is a perspective view showing a main part of the same embodiment, FIG. 3 is an enlarged side view of a portion H of FIG. 2, and FIG. FIG. 5 is a vertical sectional front view showing an example of the fixing device, and FIG. 5 is a vertical sectional front view showing another example of the conventional fixing device. 1 ... Photosensitive paper, 5 ... Heating panel, 7 ... Pressure rotation roller, 8 ... Spring, 10 ... Spring mounting plate, 11 ... Fixing roller, 15 ... Rotating shaft.

 ─────────────────────────────────────────────────── ─── Continuation of front page (56) Reference JP-A-55-33162 (JP, A) JP-A-55-40495 (JP, A) JP-A-50-2946 (JP, A) JP-A-56- 22457 (JP, A) JP-A-49-88529 (JP, A) Actually developed Shou 60-33362 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A wet method for heating and fixing a wet-developed image, comprising: a heating panel; and a pressure roller that is on the surface of the heating panel and rotates at the same speed as the conveying speed of the photosensitive paper. In a fixing device of an electrophotographic plate making machine, the heating panel has a rotation fulcrum on its photosensitive paper carry-in side, and the photosensitive paper carry-out side is suspended by a spring under a predetermined tension. A fixing roller that is in contact with the roller at a predetermined pressure and that is pressed against the heating panel by its own weight is provided downstream of the pressure rotation roller,
The upper surface on which the pressure rotating roller and the fixing roller are arranged is subjected to a treatment to reduce the friction coefficient, and the upper surface from the photosensitive paper carry-in section to the pressure rotating roller is treated to increase the friction coefficient. A fixing device for a wet electrophotographic plate making machine characterized by being applied.