JP2005025043A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus in which images are hardly affected even when heat developable photosensitive films different from each other in size are processed in the case of performing a heat developing process. <P>SOLUTION: The image forming apparatus is provided with: a film mounting means capable of accepting films of a plurality of sizes; a transport means to transport each film on the film mounting means; an exposure means to form a latent image on the transported film; and a heat developing means using a heating means 14 which has an elastic layer on a surface and visualizes the heat developable photosensitive film in which the latent image has been formed. In the image forming apparatus, the transport means transports the films of the plurality of sizes to the heat developing means with at least two or more relative positional relations, a slip plane layer comprising a fluororesin is disposed on the elastic layer surface of the heating means, the heating means comprises two or more heat sources 32a to 32c capable of separately controlling temperature and temperature sensors 33a to 33c attached to the respective heating sources, and the transport means transports the films in such a way that thermal effects that is inherent to film transport to the heating sources are made different in relative positions. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an image forming apparatus for forming an image on a plurality of photothermographic films.
[0002]
[Prior art]
In a medical imager (image forming apparatus), in order to make the image writing position of the scanning optical system with respect to the film constant, the film has a predetermined positional relationship with the scanning optical system before the film reaches the scanning exposure system. The film position is restricted. It is known that there is a so-called center reference method represented by the following Patent Document 1 and a one-side reference method disclosed in the following Patent Document 2 for this width alignment.
[0003]
In a conventional medical imager, half size (17 × 14), large angle (14 × 14), and large size (11 × 14) size films are transported so that the main scanning direction is 14 inches. Thus, the same imager can be used for processing, and other sizes such as six cuts are processed by a dedicated imager. In such a case, whichever method is adopted, there is not much difference from the viewpoint of functional performance and cost.
[0004]
However, in recent years, in addition to the above three sizes, both short and long sides such as six cuts (8 × 10) used at the output of an ultrasonic imaging apparatus are half cut (17 × 14), large angle (14 × 14), large There is a demand for an imager capable of processing a film having a size that does not coincide with four cuts (11 × 14).
[0005]
When processing such a multi-size film, which system is adopted for the film position regulation is determined as a pure mechanical problem taking into account the film size and the film transport direction.
[0006]
However, the present inventors have found that an imager employing a heat development process has the following problems specific to heat development in addition to the general problems described above.
[0007]
That is, in the heat development process, as a heating and conveying means for heating the film, as shown in Patent Document 3 below, when a method of conveying while sandwiching the film by a heating drum and a plurality of opposing rollers is adopted, In some cases, an elastic layer such as silicon rubber is provided on the surface of the heating member in order to make the contact between the heating drum and the counter roller uniform, and the surface temperature of the heating drum.
[0008]
However, as the elastic layer is processed by the photothermographic film, the organic acid or higher fatty acid contained in the photothermographic film is volatilized from the film by heating and drifts around the elastic layer. Attacks the elastic layer and tries to inhibit the cross-linking of silicon rubber.
[0009]
In addition to this, coupled with repeated heating and cooling of the heating drum itself, the elastic layer of the film passage part swells and eventually begins to crack on the surface, which is eventually transferred to the film. The Rukoto. This is because the contact state between the heating drum and the film is not uniform, and heat transfer is not uniform over the entire surface of the heating drum. If the film passing position in the heat developing section is only 14 inches, the effect is relatively large even if three sizes of half cut (17 × 14), large angle (14 × 14), and large four cut (11 × 14) are processed. It can be used until the elastic layer is cracked.
[0010]
However, if the size different from 14 inches is processed by the same imager (heat developing device), this swelling mark is generated in a portion different from the end portion of 14 inches wide. There was a bug that appeared.
[0011]
In Patent Document 4 below, when films having different sizes are continuously processed, a minimum temperature recovery time is determined according to the length, width dimension, etc. of the film, and heat development processing is performed after the minimum temperature recovery time has elapsed. Thus, a thermal development method is described in which image deterioration due to a temperature drop during continuous processing is prevented. In this case, the temperature sensor is disposed outside the passage area of the maximum size sheet, and the corrected measurement temperature is regarded as the actual temperature. In this case, when the size of the film is changed, the influence of heat due to the change cannot be sufficiently considered, and the influence on the image may not be eliminated.
[0012]
[Patent Document 1]
JP 2000-255839 A
[Patent Document 2]
Japanese Patent Laid-Open No. 2-265443
[Patent Document 3]
Japanese National Patent Publication No. 10-500497 [0015]
[Patent Document 4]
Japanese Patent Laid-Open No. 2002-244266
[Problems to be solved by the invention]
SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art, and it is an object of the present invention to provide an image forming apparatus having little influence on an image even when a photothermographic film having a different size is processed. To do.
[0017]
[Means for Solving the Problems]
In order to achieve the above object, an image forming apparatus according to the present invention comprises a film mounting means capable of loading a plurality of sheet-like heat-developable photosensitive films (hereinafter also referred to as “films”). , Conveying means for conveying the photothermographic film on the film mounting means, exposure means for forming a latent image on the conveyed photothermographic film, and visualizing the photothermographic film on which the latent image is formed An image forming apparatus having a plurality of heat sources, and wherein the conveying unit has at least two relative positions of the plurality of sizes of the photothermographic film with respect to the heat developing unit. The heat developing means includes a temperature sensor provided to control the plurality of heating sources individually or in at least two groups, and the conveying means is connected to the heating source. That film heat impact of transport, characterized in that the conveying differently in each relative position.
[0018]
According to this image forming apparatus, when the film sizes are different, each film is conveyed to the heat developing means in a different relative positional relationship, and the thermal influence on each heating source is different at each relative position. Can be detected. For this reason, when changing the size of the film, the waiting time until the start of development is improved with respect to the time accuracy compared to the case where the temperature is regarded as one temperature sensor, so when a photothermographic film having a different size is processed. However, the influence on the image is reduced.
[0019]
In the image forming apparatus, it is preferable that the plurality of temperature sensors are arranged on the opposite side of the heating source from the passage surface of the photothermographic film. By arranging the temperature sensor in this way, it is possible to better detect the thermal effect associated with film conveyance with respect to the heating source.
[0020]
Moreover, it is preferable that the said heat development means has an elastic layer on the surface of the said heat source, and also has a smooth surface layer on the outer surface of the said elastic layer.
[0021]
Preferably, the relative positional relationship includes a positional relationship corresponding to at least a 14 inch width and a positional relationship corresponding to a width different from the 14 inch width, and these positional relationships have a common film passing position. Thereby, by conveying a film on the one-side basis in the heat developing means, the thermal influence on each heating source can be made different at each relative position, and the influence of the film passing trace can be reduced.
[0022]
In this case, the film passing position is located on the front side of the apparatus, thereby facilitating film jam processing.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view showing a main part of the image forming apparatus according to the present embodiment. FIG. 2 is a perspective view of the image forming apparatus of FIG. 1 and shows a state in which the first loading unit is pulled out. FIG. 3 is a view schematically showing an exposure unit of the image forming apparatus of FIG.
[0024]
As shown in FIG. 1, an image forming apparatus 100 includes first and second loading units 11 and 12 for loading a package in which a predetermined number of photothermographic films, which are sheet-like photothermographic materials, are packaged. A supply unit 110 having a conveyance unit 5 that conveys the images one by one for exposure and development, an exposure unit 120 that exposes a film fed from the supply unit 110 to form a latent image, and a latent image is formed. A developing unit 130 that thermally develops the developed film, and a cooling and conveying unit 150 that includes a densitometer 200 and a conveying roller 144 that measure density of the developed film and obtain density information.
[0025]
The first and second loading units 11 and 12 of the supply unit 110 can be loaded with films of different sizes, and the films are conveyed one by one from the first loading unit 11 or the second loading unit 12. It is conveyed in the arrow direction (1) of FIG. 1 by the part 5 and the conveyance roller pair 139, 141. Then, the film is conveyed in the arrow direction (2) and a latent image is formed by the exposure unit 120. Next, the film is conveyed in the arrow direction (3) by the pair of conveyance rollers 142 and 143, and the latent image is visible in the heat developing unit 130. Then, it is further conveyed in the direction of arrow (4), cooled by the cooling conveyance unit 150, and then discharged to the discharge unit 160. The conveyance roller pairs 139, 141, 142, 143 and the like are rotationally driven by a motor 151 and the like in FIG. 4, and the motor 151 and the like are controlled by a control unit 152 constituted by a central processing unit (CPU) as shown in FIG.
[0026]
As shown in FIG. 2, the first loading unit 11 of the image forming apparatus 100 includes a storage tray unit 3 that can store a film by loading the film in a film package state, and a film that is provided integrally with the storage tray unit 3. A roller-feed type transport unit 5 for transporting the sheets one by one to the outside of the delivery device, and a removal unit 6 that winds and removes the barrier bag of the film package that is integrally provided on the back side of the storage tray unit 3 and loaded. And comprising.
[0027]
The first loading unit 11 is configured to be accommodated in the apparatus casing 1a of the image forming apparatus 100 and to be pulled out from the apparatus casing 1a. That is, the entire storage tray section 3 is configured to be able to be pushed into and pulled out from the apparatus housing 1a on the front surface of the apparatus, and when it is pulled out from the apparatus casing 1a in the direction H 'as shown in FIG. Thus, the film package can be loaded and maintained, and when it is pushed into the apparatus housing 1a in the direction H in FIG. 2, the light from the outside is blocked and the film can be transported at the transport position. As described above, the storage tray unit 3 of the first loading unit 11 is configured to be movable between the transport position inside the apparatus and the loading position outside the apparatus.
[0028]
Next, the conveyance unit and the removal unit in FIG. 2 will be described with reference to FIGS. FIG. 9 is a side view schematically showing a transport unit provided in the first loading unit 11 of FIG. FIG. 10 is a side sectional view schematically showing a barrier bag removing unit in the first loading unit 11 of FIG. FIG. 11 is a partially broken perspective view of a film package that can be loaded into the first and second loading sections of FIGS. 1 and 2.
[0029]
As shown in FIG. 9, the transport unit 5 is configured so that the transport roller 91 that contacts the surface BC of the film F placed in a stacked state on the mounting table 4 with a predetermined pressing force P11 rotates in the rotation direction r. The upper film F is fed to the nip roller pair 92, 93 side, and the driving roller 92 is transported while applying the nip force P12 from the driven roller 93 side to the driving roller 92 side with the film F being sandwiched between the two rollers 92, 93. The sheet is conveyed in the conveyance direction J by rotating in the rotation direction r ′ in synchronization with 91.
[0030]
In addition, when the film is transported as described above, the uppermost film F and the one or two films below it may be sent out by the transport roller 91 and transported by the nip roller pair 92, 93. It is composed of a reversible roller with a torque limiter. When a plurality of films F are sandwiched between the pair of nip rollers 92 and 93, the friction coefficient between the films F is lower than the friction coefficient between the driving roller 92 and the film F, so that the torque from the driving roller 92 is driven to the driven roller 93 side. The torque limiter is detected without being transmitted to the drive roller 92, and the driving roller 92 and the transport roller 91 synchronized therewith are reversely rotated to return the excessively transported film F to its original state.
[0031]
As shown in FIG. 11, the film package P that can be loaded in the storage tray unit 3 is, for example, stacked and positioned on a positioning member D that is positioning means as a bundle of about 125 pieces of a film F having a half-cut size. In the state, it is light-tightly accommodated in the barrier bag B which is a light shielding means. At the side end of the barrier bag B, a plurality of engaging holes a that engage with the engaging claws 26 (FIG. 3) in the barrier bag removing device are formed.
[0032]
A barrier bag removing section 6 is provided on the depth side of the storage tray section 3 in FIG. As shown in FIG. 10, the barrier bag removing unit 6 loads the film package P of FIG. 11 onto the mounting table 4 of the storage tray unit 3 of FIG. 2, and one of the guide roller pairs 11 </ b> A is a two-dot chain line of FIG. 10. The plurality of engaging holes a at the side ends of the film package P are engaged with the engaging claws 26 in the state of being moved upward, and then the side end surfaces of the film package P are sandwiched by the guide roller pair 11A. A driving roller 30 provided around 26 is driven to rotate in the rotation direction c, and the barrier bag B is removed by winding the barrier bag B around the driving roller 30, and the laminated film positioned on the positioning member D F is exposed in the storage tray section 3. Before removing the barrier bag B, the other side end face b of the barrier bag B is cut so as to be easily wound.
[0033]
Next, an alignment mechanism for positioning and aligning the film so as to be conveyed on the basis of the front side of the apparatus main body in the first and second loading sections of FIG. 1 will be described with reference to FIG. 12A is a diagram showing the storage tray portion of FIG. 2 including a film positioning mechanism, and is a cross-sectional view (a) showing a state before the storage tray portion is broken in the width direction of the film and before alignment. It is sectional drawing (b) which shows the state after alignment.
[0034]
As shown in FIGS. 12A and 12B, the storage tray unit 3 includes a mounting table 4 on which the film F is mounted, and a storage tray provided around the mounting table 4 so as to include the mounting table 4 therein. 5 is provided. The mounting table 4 is composed of a flat plate-like member, and has a stepped recess 7 serving as a storage space for the push-up plate 11 at the center.
[0035]
The storage tray unit 3 further includes a push-up plate 11B provided so as to be accommodated in the stepped recess 7 of the mounting table 4, and push-up members 14A provided on the left and right of the drawing for raising the push-up plate 11B. 15A and motors M1 and M2 as driving means for separately driving the push-up members 14A and 15B, and an alignment mechanism for aligning the film F laminated on the mounting table 4 at a predetermined position is configured. Yes.
[0036]
The push-up plate 11B is a rectangular plate-like member that directly supports the film F from below, and is accommodated so as to support the film in the stepped recess 7 when not operating, and from the stepped recess 7 by the lifting members 14A and 15A during operation. The film F is moved upward to lift the film F on the mounting table 4 to the transport position of the transport unit 5 in FIG.
[0037]
The film F is removed from the film package P of FIG. 11 loaded in the storage tray unit 3 by the barrier bag removal unit 6 of FIG. Is exposed. In this state, the push-up members 14A and 15A are provided on the left and right in the width direction of the film F perpendicular to the transport direction of the film F, operate individually by the motors M1 and M2, and lift the push-up plate 11 upward. At this time, as shown in FIG. 12B, the push-up member 14A is moved upward by the motor M1 without operating the push-up member 15A, and the push-up plate 11B is tilted and lifted upward so that Can be tilted, and the side edges F1 of the film F are aligned.
[0038]
Thereafter, when the other motor M2 is driven and the push-up member 15A is moved upward, the push-up plate 11B returns to the horizontal state, the film F on the mounting table 4 returns to the horizontal position, and the uppermost plate As shown in FIG. 9, the film F comes into contact with the transport roller 91 of the transport section 5 at the transport position and can be transported. Then, the transport roller 91 and the nip roller pairs 92 and 93 are driven, and the uppermost film F can be separated from the underlying film and transported in the transport direction J.
[0039]
As described above, the film F can be aligned on the front side of the apparatus (the front side in FIG. 2 and the left side in FIG. 9) in the storage tray portion 3 in FIG. Accordingly, the film F is conveyed as (1) and (2) in FIG. 1 with the side edges aligned with respect to the front side of the apparatus regardless of the size, and is conveyed to the heating drum 14. A film alignment mechanism that aligns the side edges of the film with the front side of the apparatus may also be provided on the upstream side of the conveying roller pair 142 of the exposure unit 120 in FIG. Each configuration of the second loading unit 12 is the same as that of the first loading unit 11 described above.
[0040]
As described above, since the film F is conveyed in the image forming apparatus 100 in a state where the side edges thereof are aligned with respect to the front side of the apparatus (one-side reference conveying method), access to the film, particularly a small size film, is possible. This is preferable because it is easy to handle jam troubles.
[0041]
Next, the exposure unit will be described. As shown in FIG. 3, the exposure unit 120 deflects the laser light L, which has been intensity-modulated based on the image signal S, by the rotary polygon mirror 113 to perform main scanning on the film F, and converts the film F into the laser light L. On the other hand, it is sub-scanned by relative movement in a direction substantially perpendicular to the main scanning direction, and a latent image is formed on the film F using the laser beam L.
[0042]
A more specific configuration of the exposure unit 120 will be described below. In FIG. 3, the image signal S which is a digital signal output from the image signal output device 121 is converted into an analog signal by the D / A converter 122 and input to the modulation circuit 123. Based on the analog signal, the modulation circuit 123 controls the driver 124 of the laser light source unit 110a to irradiate the laser beam L modulated from the laser light source unit 110a.
[0043]
The laser light L emitted from the laser light source unit 110a passes through the lens 112, is converged only in the vertical direction by the cylindrical lens 115, and rotates on the polygonal mirror 113 rotating in the direction of arrow A in FIG. Incident light is incident as a vertical line image. The rotary polygon mirror 113 reflects and deflects the laser light L in the main scanning direction, and the deflected laser light L passes through an fθ lens 114 including a cylindrical lens formed by combining two lenses and then enters the optical path. Reflected by a mirror 116 that extends in the main scanning direction, and on the scanned surface 117 of the film F that is conveyed (sub-scanned) in the arrow Y direction by the conveying device 142, the direction of the arrow X Repeat the main scan. That is, the laser beam L is scanned over the entire surface to be scanned 117 on the film F.
[0044]
The cylindrical lens of the fθ lens 114 converges the incident laser light L on the scanning surface 117 of the film F only in the sub-scanning direction, and the distance from the fθ lens 114 to the scanning surface. Is equal to the focal length of the entire fθ lens 114. As described above, the exposure unit 120 includes the fθ lens 114 including the cylindrical lens and the mirror 116 so that the laser light L is once converged on the rotary polygon mirror 113 only in the sub-scanning direction. Therefore, even if the rotary polygon mirror 113 is tilted or the shaft is shaken, the scanning position of the laser beam L is not shifted in the sub-scanning direction on the surface to be scanned 117 of the film F. It can be formed. The rotary polygon mirror 113 has an advantage that it is superior in scanning stability compared to other optical polarizers such as a galvanometer mirror. As described above, a latent image based on the image signal S is formed on the film F.
[0045]
The details of a specific chemical reaction in which a latent image is formed as described above will be described with reference to FIG. FIG. 7 is a cross-sectional view of a film F made of a heat developing material, and is a diagram schematically showing a chemical reaction in the film F at the time of exposure.
[0046]
In the film F, a photosensitive layer mainly composed of a heat-resistant binder is formed on a support (base layer) made of PET, and a protective layer mainly composed of a heat-resistant binder is further formed thereon. The photosensitive layer contains silver halide grains, silver behenate (Beh. Ag), which is a kind of organic acid silver, and a reducing agent and a toning agent. Moreover, the back surface layer which has a heat resistant binder as a main component is provided also in the back surface of the support body.
[0047]
When the exposure unit 120 irradiates the film F with the laser beam L during exposure, the silver halide grains are exposed to a region irradiated with the laser beam L as shown in FIG. Is done.
[0048]
4 to 6 are diagrams showing a configuration of the heat developing unit 130 for heating the film F. More specifically, FIG. 4 is a perspective view of the heat developing unit 130, and FIG. 6 is a cross-sectional view taken along the line IV-IV and viewed in the direction of the arrow, and FIG. 6 is a view of the configuration of FIG. 4 viewed from the front.
[0049]
The thermal development unit 130 includes a heating drum 14 as a heating member that can be heated while holding the film F in close contact with the outer periphery. The heating drum 14 has a function of forming the latent image formed on the film F as a visible image by maintaining the film F at a predetermined heat development time above a predetermined minimum heat development temperature. Here, the minimum heat development temperature is a minimum temperature at which the latent image formed on the film F starts to be thermally developed, and is, for example, 95 ° C. or higher. On the other hand, the heat development time refers to a time that should be maintained at a temperature equal to or higher than the minimum heat development temperature in order to develop the latent image on the film F to a desired development characteristic. In addition, it is preferable that the film F is substantially not thermally developed at 40 ° C. or less.
[0050]
A specific chemical reaction content in which the latent image is visualized by the heating will be described with reference to FIG. FIG. 8 is a cross-sectional view similar to FIG. 7 schematically showing a chemical reaction in the film F during heating.
[0051]
When the film F is heated to a temperature equal to or higher than the minimum heat development temperature, as shown in FIG. 8, silver ions (Ag +) are released from the silver behenate, and the behenic acid released from the silver ions forms a complex with the toning agent. . Thereafter, silver ions are diffused, and a reducing agent acts on the exposed silver halide grains as nuclei, and a silver image is formed by a chemical reaction. Thus, the film F contains photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent, and is not substantially thermally developed at a temperature of 40 ° C. or lower, for example, at a temperature of 95 ° C. or higher. Heat developed.
[0052]
As shown in FIGS. 4 and 5, a plurality of rotatable opposing rollers 16 having a smaller diameter than the heating drum 14 as a guide member and a pressing member are provided outside the heating drum 14. Are arranged so as to face each other in parallel.
[0053]
The opposing roller 16 is made of stainless steel, and the upstream three pieces 16a, 16b, 16c are configured as solid large-diameter rollers having a diameter of, for example, 12 mm, and the opposing roller 16d adjacent to the downstream and the most downstream opposing roller The remaining counter rollers 16 up to 16e are formed into tubular small diameter rollers having a diameter of, for example, 8 mm. The counter roller 16 preferably has a heat capacity of 0.16 kJ / K or more, and the stainless steel as the material of the counter roller 16 has a heat capacity of about 0.18 kJ / K.
[0054]
At both ends of the heating drum 14, three guide brackets 21 supported by the frame 18 are provided on one side. By combining the guide bracket 21, opposing C-shapes are formed at both ends of the heating drum 14.
[0055]
The guide bracket 21 integrally holds a plurality of opposing rollers 16 at both ends, and the holding position by the guide bracket 21 can be adjusted. That is, by adjusting the position of the guide bracket 21, the positions of the plurality of opposing rollers 16 with respect to the heating drum 14 can be adjusted. Thereby, since the parallelism between the heating drum 14 and the opposing roller 16 in the axial direction of the heating drum 14 can be adjusted appropriately, the film can be uniformly adhered to the outer peripheral surface of the heating drum 14. In particular, when a smooth surface layer such as a fluororesin is provided on the outer peripheral surface of the heating drum 14 as described later, density unevenness is likely to occur due to such a deviation in parallelism, but the parallelism can be adjusted. By configuring, it is possible to realize a configuration capable of preventing such density unevenness.
[0056]
Each guide bracket 21 has nine elongated holes 42 extending in the radial direction. From this long hole 42, shafts 40 provided at both ends of the opposing roller 16 protrude. One end of each coil spring 28 is attached to the shaft 40, and the other end of each coil spring 28 is attached near the inner edge of the guide bracket 21. Accordingly, each counter roller 16 is urged toward the outer periphery of the heating drum 14 with a predetermined force based on the urging force of each coil spring 28. When the film F enters between the outer periphery of the heating drum 14 and the opposing roller 16, the film F is pressed against the outer peripheral surface of the heating drum 14 with such a predetermined force, thereby heating the film F uniformly over the entire surface. To do.
[0057]
A shaft 22 coaxially connected to the heating drum 14 extends outward from the end member 20 of the frame 18 and is rotatably supported by the end member 20 by a shaft bearing 24. A gear (not shown) is formed on a rotating shaft 23 of a microstep motor (not shown) disposed below the shaft 22 and attached to the end member 20. On the other hand, a gear is also formed on the shaft 22. The power of the microstep motor is transmitted to the shaft 22 via a timing belt 25 (a belt on which the gear is engraved) that connects both gears, whereby the heating drum 14 rotates. Note that power transmission from the rotary shaft 23 to the shaft 22 may be performed via a chain or a gear train instead of a timing belt.
[0058]
As shown in FIG. 6, in the present embodiment, the opposing roller 16 is provided in the circumferential direction of the heating drum 14, and the two reinforcing members 30 (FIG. 6) connect the both end members 20 of the frame 18. It connects and supports the both-ends member 20 additionally.
[0059]
A plate-like heater 32 is attached to the inner periphery of the heating drum 14 over the entire periphery, and the outer periphery of the heating drum 14 is heated under the control of the control electronic device 34 shown in FIG. Yes. Power is supplied to the heater 32 through a slip ring assembly 35 connected to the electronic device 34.
[0060]
The heater 32 is attached to the inner periphery of the heating drum 14 in order to heat the outer peripheral surface of the heating drum 14. As the heater 32 for heating the heating drum 14, for example, an etched resistive foil heater can be used. The heater 32 is divided into three in the longitudinal (rotating axis) direction (film width direction) of the heating drum 14 and disposed on the inner periphery of the heating drum 14 as shown in FIG.
[0061]
The electronic device 34 for controlling the heater rotates together with the heating drum 14 so that the electric power supplied to the heater 32 can be adjusted according to the temperature information sensed by the temperature detecting means disposed on the heating drum 14. It has become. The control electronic device 34 controls the outer surface temperature of the heating drum 14 by controlling the heater 32 so that the temperature is suitable for the development of the specific film F. In the present embodiment, the heating drum 14 can be heated to a temperature of 60 ° C to 160 ° C.
[0062]
Here, it is preferable to maintain the temperature in the width direction of the heating drum 14 within 2.0 ° C. (particularly within 1.0 ° C.) by the heater 32 and the control electronic device 34. In the present embodiment, the temperature is maintained within 0.5 ° C.
[0063]
As shown in FIG. 5, the heating drum 14 includes a rotatable cylindrical aluminum support tube 36, a flexible elastic layer 38 made of silicon rubber or the like attached to the outside of the support tube 36, and an elastic layer. And a smooth surface layer 39 formed as an outermost peripheral surface by coating the outer periphery of 38 with a fluororesin by coating or the like.
[0064]
The thickness and thermal conductivity of the elastic layer 38 are selected so that continuous processing of the plurality of films F can be performed efficiently, and the thermal conductivity is preferably 0.5 W / k or more. The hardness of the elastic layer 38 is preferably JIS-A hardness 20 to 70 degrees. The elastic layer 38 may be indirectly attached to the support tube 36.
[0065]
The elastic layer 38 can be composed of rubber or a rubber-like member, and the rubber or rubber-like member widely includes various materials having elasticity similar to that of the rubber material in addition to various rubber materials and thermoplastic elastomers. For example, various rubber materials, resin materials, thermoplastic elastomers and the like may be used alone or in combination. In this case, the various rubber materials are not limited. For example, in addition to a solid rubber material, a liquid reaction cured product obtained by curing a liquid viscoelastic body may be used.
[0066]
Solid rubber materials include, for example, ethylene propylene terpolymer (EPDM), butyl rubber, polyisobutylene, ethylene propylene rubber, chlorofrene rubber, natural rubber, styrene butadiene rubber, butadiene rubber, styrene-isobrene-styrene, For polymers using styrene-butadiene-styrene, urethane rubber, etc. alone or in combination, vulcanizing agents, cross-linking agents, vulcanization accelerators, vulcanization acceleration assistants conventionally used in the rubber industry in general. And vulcanized (or cross-linked) containing chemicals such as an agent, tackifier, filler, plasticizer, anti-aging agent, and solvent.
[0067]
The liquid rubber material includes, for example, urethane, liquid polybutadiene, modified silicon, silicon, polysulfide and the like. In addition, it is preferable to use these materials by adding a predetermined amount of a curing agent for solidification, mixing and reaction curing. The elastic layer 38 may be formed in a dense state or a sponge shape.
[0068]
Examples of the fluororesin applied to form the smooth surface layer 39 include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), tetrafluoroethylene and herfluoroalkoxy. Compounds such as a copolymer of ethylene (PFA), a copolymer of ethylene and tetrafluoroethylene (ETFE), and a copolymer of tetrafluoroethylene and hexafluorobroylene (FEP) are used.
[0069]
When the film F is heated around the heating drum 14 for heat development, for example, a gas containing a chemical component such as an organic acid is generated, but fluorine that constitutes the smooth surface layer 39 provided on the surface of the elastic layer 38. Since the resin has chemical resistance, it does not react with gas components such as organic acids and does not deteriorate. In addition, the fluororesin blocks such gas components from permeating, and the elastic layer 38 made of silicon rubber or the like does not come into contact with gas components such as organic acids, so that the gas components do not deteriorate or deteriorate. . Therefore, the elastic layer 38 hardly changes in its shape and physical properties over time, so that the initial elastic force and thermal conductivity can be maintained.
[0070]
The thickness of the smooth surface layer 39 is preferably 10 μm or more from the viewpoint of preventing deterioration of the elastic layer 38 due to a gas component such as an organic acid, and preferably 60 μm or less from the viewpoint of preventing uneven density.
[0071]
Further, the urging force of the coil spring 28 determines the pressing force of the facing roller 16 so that the film F is securely adhered to the outer peripheral surface of the heating drum 14 and is stably conveyed while receiving sufficient heat transfer. Therefore, care must be taken in selecting the value. That is, if the biasing force of the coil spring 28 is too small, heat is conducted non-uniformly to the film F, so that image development may be incomplete, and film conveyance may become unstable.
[0072]
Next, in the image forming apparatus 100 of FIGS. 1 and 2, the relative positional relationship in the heating drum and the divided heater and temperature of the heating drum when films of different sizes are conveyed from the first and second loading units 11 and 12 The relationship with the arrangement position of the sensor will be described with reference to FIG. 13, FIG. 14, and FIG. FIG. 13 is a right side view of the heating drum of FIG. 1 (the counter roller and the like are omitted). FIG. 14 is a right side view of the heating drum showing a conventional relative positional relationship in the heating drum when films of different sizes are conveyed. FIG. 15 is a block diagram showing a control system for controlling the divided heater and the transport system in the heating drum of FIG.
[0073]
The heater 32 disposed on the inner periphery of the heating drum 14 in FIGS. 5 and 6 is divided into three heaters 32a, 32b, and 32c divided into three in the longitudinal direction of the heating drum 14 (film width direction) as shown in FIG. The temperature sensors 33a, 33b, and 33c are arranged on the inner peripheral surface side of the heating drum 14 in the vicinity of each of the divided heaters 32a to 32c. As described above, since the temperature sensors 33a to 33c are arranged on the opposite side of the film passing surface of the heating drum 14, it is possible to better detect the thermal influence accompanying the film conveyance with respect to the divided heaters 32a to 32c.
[0074]
As shown in FIG. 15, the divided heaters 32 a to 32 c are controlled to be energized independently by the control unit 152 based on output signals from the temperature sensors 33 a, 33 b, and 33 c.
[0075]
4 and 15 includes a central processing unit (CPU), and when the film size is switched, the film conveyance is prohibited for a predetermined period and the heating drum 14 returns to the processable temperature. Based on the output signals from the temperature sensors 33a to 33c, the time is further calculated by the calculation unit 153 in consideration of the film size information input from the input unit 154. After the calculation time has elapsed, the above-described prohibition of film conveyance is performed. It is designed to be released. Note that the input unit 154 inputs film size information so as to automatically read from the barcode information section attached to the film package P when the film package P of FIG. 11 is loaded in the loading units 11 and 12. You can
[0076]
Further, as shown in FIG. 13, the width D of the heating drum 14 in the rotation axis direction corresponds to the maximum usable film size (14 inch width), and the stability in the drum width direction of the maximum size film. In consideration of the above, the divided heaters 32a to 32c and the temperature sensors 33a to 33c are arranged symmetrically with respect to the center in the width direction of the drum.
[0077]
As shown in FIG. 13, when the film is heated, it is divided into three divided heaters 32a to 32c that can be individually energized and temperature sensors 33a to 33c arranged corresponding to the divided heaters. In the case of a film having a maximum size (14 inches wide) corresponding to the range of the width D in FIG. 13, the temperature effect associated with the passage of the film appears in the three heating zones. . Further, in the case of a small-sized film corresponding to the range of the width C in FIG. 13, the temperature effect associated with the passage of the film appears in two adjacent heating zones (32a, 33a, 32b, 33b).
[0078]
With the configuration as described above, according to the image forming apparatus of the present embodiment, for example, when processing a small size film, the temperature information of the temperature sensors 33 a and 33 c as the temperature profile information in the longitudinal direction of the heating drum 14. Therefore, the return time until the processable temperature is reached can be calculated more accurately when the next film of different size is processed based on the three pieces of temperature information. It is possible to reduce the influence on the image. On the other hand, according to the conventional symmetrical center reference conveyance system as shown in FIG. 14, the temperature effect appears only in one heating zone, the temperature information of the temperature sensors 33a and 33c is the same, and the sizes are different. When processing film, only two pieces of temperature information can be used, so when changing the film size, the calculation of the recovery time until the processable temperature is reached becomes inaccurate, and the effect on the image due to density fluctuations etc. Is likely to appear. In this way, the influence on the image can be reduced when films of different sizes are processed.
[0079]
In addition, since the return time can be calculated by taking into account the size information of the film, the temperature sensor has both a relatively large film (four cuts, etc.) and a small film (six cuts, etc.). On the other hand, even in the case of sharing, the return time can be calculated with high accuracy.
[0080]
The temperature sensors 33a and 33b are preferably located within a width C through which the film passes during processing of a small-sized film, but may be arranged at a position where there is a temperature effect associated with the passage of the film. .
[0081]
When the film is conveyed to the heating drum 14 in FIG. 13, the film is conveyed with the side end F1 of the film aligned with the front side of the apparatus as shown in FIG. 12B regardless of the size. Thus, any size film is heated while being conveyed on the outer peripheral surface of the heating drum 14 along the reference line G0. For example, a small-size film (such as a six-cut film having a width C of 8 or 10 inches) has a side drum along the reference line G0 and the other side edge along the small size line G1 corresponding to the width C. Carried over. Also, large-sized films (half-cut, large-angle, large partitions, etc. with a width D of 14 inches) are heated along the large-size line G2 whose side ends are along the reference line G0 and whose other side ends correspond to the width D. It is conveyed on the drum 14. Accordingly, it is possible to reduce the number of film passing traces that may affect the image during conveyance of a large size film to one, which is preferable.
[0082]
When a relatively small size film is conveyed on the heating drum 14 while being continuously heated, and then a relatively large size film is heated and conveyed, the film is placed on the elastic layer 38 on the outer peripheral surface of the heating drum 14. 5 and 6, a smooth surface layer 39 made of a fluororesin is formed, and deterioration such as swelling of the elastic layer 38 during use of the heating drum 14 can be prevented. Therefore, in the vicinity of the small size line G1 It is possible to prevent an influence on an image such that a film swelling mark remains on the film as a film conveyance mark. Thus, by using the heating drum 14 having the smooth surface layer 39 on the surface of the elastic layer 38, the influence of the film passage trace on the image can be greatly suppressed.
[0083]
Conventionally, in a heat development part for developing a silver salt photothermographic film using an organic solvent, when the photothermographic film is developed, the surfactant on the film surface layer or the organic solvent or organic acid from the emulsion layer is developed. Etc. are released from the film and attacked by an elastic body such as silicon rubber on the surface layer of the heating drum, the elastic body deteriorates, causing the elastic body to swell and wear, and a stable finished image quality cannot be obtained. In contrast to the problem, in the present embodiment, the surface activity of the film surface layer is developed when the photothermographic film is developed by forming the smooth surface layer 39 containing the fluororesin on the elastic layer 38. Stable finish image quality can be obtained by preventing the organic solvent or organic acid from the agent or emulsion layer from attacking the high conductivity elastic body and preventing the elastic body from deteriorating over time. To become.
[0084]
Next, a guide member for first guiding the film F away from the heating drum 14 in FIG. 5 will be described. As shown in FIG. 5, a guide member 210 for separating the developed film F from the heating drum 14 and guiding it in the conveyance direction is located below the most downstream counter roller 16e between the heating drum 14 and the conveyance roller pair 144a. Has been placed. That is, the guide member 210 is arranged such that the guide surface 300 first guides the film F after the film F is conveyed between the heating drum 14 and the opposing roller 16 and separated from the outermost smooth surface layer 39. Has been.
[0085]
In the image forming apparatus 100 of FIG. 1, the film in the softened state after heat development on the guide surface 300 of the guide member 210 of FIG. 5 arranged close to the heating drum 14 is cooled and conveyed in FIG. 1 of the next step through the conveyance roller pair 144a. It is possible to guide to the portion 150 stably.
[0086]
In order to keep the gap between the leading end of the guide that guides the film separated from the heating drum to the cooling conveyance unit and the heating drum constant, it is conceivable to use an abutment roller system. Does not swell, etc., so that the diameter is constant at the longitudinal position of the drum, so that the gap between the guide tip and the heating drum can be reliably maintained constant, and there is no possibility of damaging the outer peripheral surface of the heating drum.
[0087]
As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to these embodiments, and various modifications can be made within the scope of the technical idea of the present invention. For example, in FIG. 5, the number of opposed rollers having a large heat storage capacity on the upstream side can be appropriately increased or decreased, and the wall thickness may be appropriately increased from a large-diameter tubular roller. Further, the material may be composed of a steel material other than stainless steel or an aluminum material. Further, the diameter of the opposing roller may be changed in three steps or more, or rollers having different diameters may be alternately arranged.
[0088]
Further, as shown in FIG. 16, the heater may be divided into two, and the two heaters are constituted by the divided heaters 32a and 32b and the temperature sensors 33a and 33b corresponding to the divided heaters, and the one-side reference along the reference line G0. By changing the film size, as described above, since the film conveyance has a different influence on each heating zone and the temperature information from the temperature sensors 33a and 33b is different when conveying a small size film. Can accurately calculate the return time.
[0089]
【The invention's effect】
According to the present invention, it is possible to provide an image forming apparatus having little influence on an image even when a photothermographic film having a different size is processed when a heat development process is performed.
[Brief description of the drawings]
FIG. 1 is a front view showing a main part of an image forming apparatus according to an embodiment.
FIG. 2 is a perspective view of the image forming apparatus of FIG. 1, showing a state in which a first loading unit is pulled out.
3 is a view schematically showing an exposure unit of the image forming apparatus of FIG. 1. FIG.
4 is a perspective view of a heat development unit 130 in FIG. 1. FIG.
5 is a cross-sectional view of the configuration of FIG. 4 taken along the line IV-IV and viewed in the direction of the arrows.
6 is a front view of the configuration of FIG.
FIG. 7 is a cross-sectional view of a film in the present embodiment, schematically showing a chemical reaction in the film during exposure with a laser beam.
8 is a cross-sectional view of a film in the present embodiment, and is a diagram schematically showing a chemical reaction in the film when the film on which the latent image as shown in FIG. 7 is heated is shown.
FIG. 9 is a side view schematically showing a transport unit provided in the first loading unit 11 of FIG. 2;
10 is a side cross-sectional view schematically showing a barrier bag removing unit in the first loading unit 11 of FIG. 2; FIG.
11 is a partially cutaway perspective view of a film package that can be loaded into the first and second loading sections of FIGS. 1 and 2. FIG.
12A is a view showing the storage tray portion of FIG. 2 including a film positioning mechanism, and is a cross-sectional view showing a state before the storage tray portion is broken in the width direction of the film and before alignment. FIG. It is sectional drawing (b) which shows the state after a) and alignment.
13 is a right side view showing the arrangement position and the like of the divided heater and temperature sensor of the heating drum in FIG. 1 (the counter roller and the like are omitted).
FIG. 14 is a right side view of a heating drum showing a relative positional relationship according to the conventional center reference method in the heating drum when films of different sizes are conveyed.
15 is a block diagram showing a control system for controlling a divided heater and a transport system in the heating drum of FIG. 13;
16 is a right side view showing a modified example of the arrangement position of the divided heater and temperature sensor of the heating drum in FIG. 13 (the counter roller and the like are omitted).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Image forming apparatus 130 ... Heat developing part 11, 12 ... Loading part 14 ... Heating drum 16 ... Opposing roller 32 ... Heater 32a-32c ... Divided heater (heating source) )
33a to 33c ... temperature sensor 38 ... elastic layer 39 ... smooth surface layer (surface layer)
DESCRIPTION OF SYMBOLS 120 ... Exposure part 130 ... Heat developing part 139, 141, 142, 143 ... Conveying roller pair 152 ... Control part 153 ... Calculation part F ... Film (thermodevelopment photosensitive film)

Claims (5)

Film mounting means capable of loading a plurality of sheet-shaped photothermographic films;
Conveying means for conveying the photothermographic film on the film placing means;
Exposure means for forming a latent image on the conveyed photothermographic film;
A heat developing means having a plurality of heating sources for visualizing the heat developable photosensitive film on which the latent image is formed, and an image forming apparatus comprising:
The transport means transports the photothermographic films of the plurality of sizes to the heat development means in a relative positional relationship of at least 2;
The thermal development unit includes a temperature sensor provided to control the plurality of heating sources individually or in at least two groups,
The image forming apparatus, wherein the transport unit transports the heat source so that a thermal influence accompanying the film transport differs at the relative positions. The image forming apparatus according to claim 1, wherein the plurality of temperature sensors are arranged on a side opposite to a passage surface of the photothermographic film of the heating source. The image forming apparatus according to claim 1, wherein the heat developing unit includes an elastic layer on a surface of the heating source, and further includes a smooth surface layer on an outer surface of the elastic layer. 2. The relative positional relationship includes a positional relationship corresponding to at least a 14-inch width and a positional relationship corresponding to a width different from the 14-inch width, and these positional relationships have a common film passing position. , 2 or 3. The image forming apparatus according to claim 4, wherein the film passing position is located on a front side of the apparatus.

Images