JPH0827530B2 - Polymerization / conveyance device of heat developing machine - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a thermal developing apparatus having a heating means for applying stable and uniform heat to a photosensitive element and an image receiving element in a thermal developing machine.

[Conventional technology]

With respect to diffusion transfer type heat development in which a diffusible dye is released by heat development and the dye is transferred to an image receiving element to separate the silver image and the dye to obtain a color image,
There have been many technical disclosures regarding a photosensitive element, an image receiving element, a thermal development method and an apparatus therefor, and as a typical example, a dye fixing layer surface and a photosensitive layer are provided between a pair of rollers capable of uniformly heating and pressing. It is carried out by passing the image-receiving element and the photothermographic element in an overlapping manner so that the layer surfaces are aligned.

Then, the two overlapping elements are uniformly heated and subjected to heat development, the dye released from the photothermographic element by heat development is transferred to the dye fixing layer, and then the above two sheets are peeled off to receive an image. Images can be rendered on the element.

In this method, in the heat development transfer portion, it is necessary to maintain the superposed state because the transfer needs to be performed sufficiently. Therefore, normally, in the heat development transfer section, the photosensitive element and the image receiving element are conveyed in a superposed state between the pair of conveyor belts.

[Problems to be solved by the invention]

However, in the structure of this type of heat development transfer unit, although the belts are strongly adhered between the entrance side belt wheels and the exit side belts, each belt is caused only by its tension between the entrance side and the exit side. Since both elements are only sandwiched, there is a limit to increasing the adhesion force, and since there is a tendency to be unrestrained, the belt may wavy or shift as it travels, causing transfer unevenness. is there.

On the other hand, in heat development transfer, if the transport speed is slow, even if it is once heated, it will be cooled, and temperature unevenness will occur in the transport direction. Therefore, uniform heating is required.
Atmosphere heating or a long flat heating plate extending from the inlet side to the outlet side must be prepared. In the atmosphere heating, the response of the temperature control is poor, and in the flat heating plate, a part where the belt and the heating plate do not adhere to each other due to unstable running of the belt, resulting in uneven temperature, and therefore this surface The transfer unevenness may also occur.

Further, from the above meaning, it is desired that both belts strongly and uniformly adhere from the inlet to the outlet. However, if the adhesive force is uniform in the entire transport area, a defective adhesion may occur at the start of superposition, resulting in defective adhesion. The strain force accumulated between the mating surfaces of the parts cannot escape to anywhere, and reaches the exit, leaving a transfer unevenness.

Therefore, the main object of the present invention is to reliably and stably bring the photosensitive element and the image receiving element into close contact with each other from the entrance to the exit substantially evenly. Therefore, it is an object of the present invention to provide a stacking / conveying device which can solve the above-mentioned problems and thus does not cause uneven transfer.

[Means for solving the problem]

The above-mentioned object is to dispose a conveyor belt in which a belt is wound around a roller so as to face one heating rotary drum so that the belt is along its surface, and to provide a photosensitive element and an image receiving element between the heating rotary drum and the belt. The conveyor belt is configured to be conveyed in an overlapping state, and two conveyor belts are provided apart from each other in the rotation direction of the heating rotary drum, and the belt between these two conveyor belts is not pressed against the heating rotary drum. At
The problem can be solved by forming the portion for changing the pressing force for the photosensitive element and the image receiving element.

[Action]

In the present invention, the drum and the belt convey the respective elements in a superposed state. Therefore, the tension of the belt acts uniformly on the entire surface facing the belt, and uniform pressing is possible, and even adhesion of both elements is obtained, and the adhesion is easy in proportion to the tension of the belt. Can be increased, especially when the element thickness is thin. Further, since each element follows the curvature of the drum surface, it has excellent running stability and does not separate from the drum. For these reasons, the occurrence of transfer unevenness is prevented.

Further, by using a heating drum as the drum, uniform heat can be applied to both elements for a long time with good responsiveness, and transfer unevenness can be prevented also in this aspect.

Further, even if the adhesion unevenness occurs at the start of the superposition, the distortion of the adhesion failure portion is released by the pressing force changing portion, so that it is evened out with other portions. further,
Since two conveyor belts are separately wound in the rotating direction of the heating rotary drum, a uniform pressing force acts on the whole including the portion where the distortion is released by the subsequent conveyor belt. As compared with the case where two conveyor belts are provided, the adhesion as a whole is guaranteed, and the occurrence of adhesion and transfer unevenness is prevented.

〔Concrete example〕

 The present invention will be described in more detail below.

As the belt that can be used in the present invention, a heat-resistant belt is used so as to withstand the maximum temperature of heat development, and a belt having a tensile strength that can withstand a required pressing force is used. Preferably, a metal belt made of stainless steel or the like, a carbon-containing silicon rubber having a heat-resistant fiber as a core material, a fluororubber belt, or the like is used, and a contact surface with each element is preferably a smooth surface for improving adhesion. .

The belt is wound around a plurality of belt wheels to form a conveyor belt, and at least one of the belt wheels is a drive belt wheel.

On the other hand, the heating rotary drum of the present invention has a large diameter and is heat resistant and has a smooth surface. As the material, metal, heat-resistant plastic or rubber can be used, but metal having excellent thermal conductivity is particularly preferable.

For this drum, a plurality of the conveyor belt,
The belt is arranged so as to face the surface of the heating rotary drum while being separated from the surface of the heating rotary drum. By arranging the two conveyor belts so as to face one drum, a belt pressing force changing portion is provided between the conveyor belts.

The pressing force changing unit serves as a strain releasing changing unit in which the pressing force does not act on the photosensitive element and the image receiving element between the conveyor belts.

By changing the tension force between the plurality of conveyor belts, it is possible to further change the pressing force applied to both elements. The mode of changing the pressing force may be weak to strong or strong to weak, and can be appropriately determined depending on the layer constituent material of each element.

In the belt overlapping area of a certain conveyor belt, by providing a pressure cola that presses against the drum from the inside of the belt, at this pressure roller position,
It is also possible to temporarily increase the pressing force on both elements and then restore the pressing force. In this case, the pressure roller serves as a pressing force changing unit that collapses the strain.

This aspect can be applied to at least one of the plurality of conveyor belts of the present invention.

For thermal development, the drum is used as a heating drum, and hot air is supplied to part or all of the overlapping area.
Alternatively, heat can be applied to the light-sensitive element and the image-receiving element by placing the entire heat-development and transfer section in a heated atmosphere, or by combining these methods.

The heating temperature required for the heating step for heat development and heat transfer is preferably 80 to 250 ° C, more preferably 100 ° C to
In the range of 200 ° C., the time is preferably 0.1 seconds to 300 seconds, more preferably 5 seconds to 180 seconds, and the optimum time is determined at each temperature.

The overlay pressure at the heat development transfer section is 0.01-10
0 kg / cm ^2, particularly 0.1~50kg / cm ² is preferred. If the photosensitive element and the image receiving element are completely adhered to each other within the above pressure range, for example, through a pair of rolls facing each other, as a pre-process of the thermal development transfer section according to the present invention, heat development at an excessively high pressure 1 kg / cm ² or less
It may be preferably 500 g / cm ² or less, and particularly preferably 100 g / cm ² or less.

It is preferable that the belt be provided with a tension roller that is positionally adjustable or urged by a spring or the like in order to maintain a required superposition pressure and improve running stability such as slip prevention.

Next, further detailed description will be given with reference to the embodiment shown in FIGS. 1 to 3. In FIG. 1, reference numeral 1 is a heating rotary drum having a heater therein. X is the first conveyor belt, Y is the second
With a conveyor belt, the pressure roller 3, 4 and 7, 8 and the tension roller 5, 9 respectively to the belt 6,
The belt 10 is wound around, and between the first conveyor belt X and the second conveyor belt Y, there is a pressing force changing portion having a length l and having no belt.

As shown by the arrows, both elements have the position of the pressure bonding roller 3 as the inlet, the position of the pressure bonding roller 4 as the outlet, and then pass through the pressing force changing portion having the length l to move from the position of the pressure bonding roller 7 to the inside of the second conveyor belt. It digs in and is discharged from the pressure roller 8 position.

Both elements are subjected to heat from the drum 1 in the overlapping region from the position of the pressure roller 3 to the position of the pressure roller 8 in the overlapping region, and are subjected to heat development and transfer. Further, the poor adhesion portion is eliminated by suddenly releasing the pressing force in the pressing force changing portion, diffusing the strain, and subsequently applying the adhesive force.

FIG. 2 shows that the pressure rollers 3, 8 are arranged at the front of the drum 1 to lengthen the overlapping area, and substantially the same as the first embodiment.
It is based on the same idea as the illustrated example.

FIG. 3 shows that with one conveyor belt Z,
This is a reference example in which a pressure roller 11 for pressing the belt 2 from the inside of the belt to the drum 1 with a spring or the like is provided.
The pressure roller 11 may be retracted after being pressed.

In this case, the pressure of the pressure roller 11 increases the pressing force to crush and diffuse the defective adhesion portion.
It can be applied to at least one of the second conveyor belt Y.

The entire heat developing apparatus having the above heat developing and transferring section can be configured as shown in FIG. 4, for example. In this example, a heat development transfer section similar to that in the example of FIG. 1 is applied.

Explaining this, the roller-shaped photothermographic element 20 is
Guided by guide roller 21, reaches the exposure position, CRT2
Imagewise exposure by 2. On the other hand, the image-receiving element 23 has a flat plate-shaped heater 24 in the preceding stage where it is superposed on the exposed and exposed element 20.
By A, preheating is performed from the surface of the image receiving element 23 opposite to the overlapping surface. Also, preferably,
It is desired that the photosensitive element 20 also be preheated by the flat-plate heater 24B before being superposed on the image receiving element 23.

The photosensitive element 20 and the image receiving element 23 that have been preheated are superposed by a pair of heating rollers 25 and 26, and are brought into contact with each other by heating and pressure contact, and are guided to the guide plates 27 and 27 as the heating rollers 25 and 26 rotate. And is supplied to the heat development transfer section. Both discharged elements reach the separating roller 31 via the guide rollers 28, 29, 30 and the photosensitive element 20 having undergone the thermal development transfer is wound by the winding roll 32 arranged on the lower side of the exit side. Due to the downward force that accompanies the winding, the image receiving element 23
Is separated from the photosensitive element 20 and separated, and is sent to the cutting position by the feed rolls 33 and 34, where it is cut into a predetermined length by the cutter 35 and accumulated in a sheet shape in the storage section 36.

The light-sensitive element in the present invention can be obtained, for example, by coating and drying a material containing a dye-donating polymer, silver halide and an organic silver salt on a support, using a hydrophilic binder as a binder.

Further, the image-receiving element is produced by applying an image-receiving layer containing a moldant polymer for fixing the heat transferable dye that diffuses and moves from the photothermographic element to a support such as paper or other synthetic polymer sheet. can do.

The form of the light-sensitive element or the image-receiving element in the present invention may be a sheet shape in addition to the roll shape of the above example.

The image-receiving layer of the image-receiving element effectively used may have a function of receiving the dye in the photothermographic layer which is released or formed by thermal development, and is, for example, a polymer containing a tertiary amine or a quaternary ammonium salt. U.S. Pat.No. 3,709,690
Those described in No. 10 are preferably used. Examples include polymers containing ammonium salts and polymers containing tertiary amines. As a typical image receiving layer for diffusion transfer,
It can be obtained by mixing a polymer containing an ammonium salt, a tertiary amine or the like with gelatin, polyvinyl alcohol or the like and coating the mixture on a support. Other useful dye-receiving substances include those formed of heat-resistant organic polymer substances having a glass transition temperature of 40 ° C. or higher and 250 ° C. or lower described in JP-A-57-207250. These polymers may be carried on the support as an image receiving layer, or may be used as the support themselves.

As the support for the light-sensitive element and the image-receiving element, any support such as a transparent support and an opaque support may be used.For example, a film such as polyethylene terephthalate and a pigment such as titanium oxide may be contained in these supports. Support, baryta paper, RC paper laminated with thermoplastic resin containing pigment on paper, cloth, glass, metal such as aluminum, etc., and electron beam curing containing pigment on these supports Examples of the support include a support obtained by coating and curing the functional resin composition, and a support having a coating layer containing a pigment provided on the support.

By the way, it is considered that a considerable amount of water or gas is present in the image receiving layer, particularly in the case of a paper support. The moisture and gas contained in the image receiving element interfere with the adhesion between the two elements as steam and gas in the process of heat development and diffusion transfer by superimposing the photothermographic element and the image receiving element on each other to cause serious transfer unevenness. It is thought to cause.

Therefore, as shown in the example of FIG. 5, it is desirable to carry out preliminary heating prior to the heat development transfer step.

The preheating temperature of each of the image receiving element and the heat-developable photosensitive element suitable for further combination may be a temperature and time sufficient to remove water substantially, and the preheating step of the image receiving element and the photosensitive element preferably combined. The heating temperature in the preheating step is preferably 80 ° C. to 250 ° C., more preferably 100 ° C. to 200 ° C., and the heating is performed for a time necessary to sufficiently remove the respective water contents.

Therefore, when the preheating temperature is high, it is short, and when the preheating temperature is low, a long time is required. The time also varies depending on the type and material of the image receiving element, the photosensitive element and the like. For example, when the support of the image receiving element is a paper support or the like, sufficient preheating is necessary, and when it is a PET base or the like, the preheating time may be short. Further, for example, when the binder of the image-receiving layer and the photosensitive layer is a hydrophilic binder represented by gelatin, PVA, PVP or the like, sufficient preheating is necessary, and when the binder is a hydrophobic binder, it may be relatively short. Good.

The general heating time is preferably 0.1 second to 60 seconds, more preferably 1 second to 20 seconds.

As an imagewise exposure method for recording a latent image on a heat-developable photosensitive element, exposure may be carried out by a general exposure method such as an ordinary color printer, or by optically converting computer data or video signals and scanning exposure.

Therefore, as the light source, a halogen lamp such as a tungsten lamp, a mercury lamp, and an iodine lamp, and a CRT, an OFT, an LED, a laser, and the like can be generally cited.

〔The invention's effect〕

As described above, according to the present invention, the adhesion between the photosensitive element and the image receiving element is improved, and the transfer unevenness can be prevented.

[Brief description of drawings]

1 and 2 are schematic views of a specific example of a superposing / conveying device for performing thermal development / transfer according to the present invention, FIG. 3 is a schematic view of a reference example, and FIG. 4 is a schematic view of an entire heat developing machine. Is. 1 ... Heating rotary drum 3, 4, 7, 8 ... Crimping roller, 5, 9 ... Tension roller, 6, 10 ... Belt,
11 ... Pressure roller (pressing force changing part), l ... pressing force changing part, X, Y, Z ... conveyor belt, 20 ... photosensitive element, 23 ...
… Image receiving element.

 ─────────────────────────────────────────────────── --Continued from the front page (56) References JP-A-55-38544 (JP, A) JP-A-61-153651 (JP, A) JP-B-41-11432 (JP, B1)

Claims (1)

[Claims] 1. A conveyor belt, in which a belt is wound around a roller, is disposed so as to face one heating rotary drum so that the belt extends along the surface thereof, and a photosensitive element and an image receiving element are provided between the heating rotary drum and the belt. Are configured to be conveyed in an overlapping state, the two conveyor belts are provided apart from each other in the rotation direction of the heating rotary drum, and the belt between these two conveyor belts is not pressed against the heating rotary drum. A superposing / conveying device for a heat developing machine, characterized in that a portion for changing a pressing force with respect to a photosensitive element and an image receiving element is formed in a portion.