JP2003043656A - Thermal developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermal developing device capable of preventing an energizing roller from floating up, capable of maintaining the uniform and tight contact between a heating drum and a heat developable film without increasing the energizing force of the energizing roller, and capable of preventing irregularities in developing the heat developable film. SOLUTION: In the thermal developing device, a visible image is obtained by feeding a film F with a latent image to a drum 14, and heating the film F so as to thermally develop the film while carrying the film F interposed between the drum 14 and several rollers 16. The roller is energized so that the press contact force may be <=7 gf/cm with reference to the film, and an angle formed between the film entering track at feeding the film to the drum and a tangent (a) at the contact part (b) of the roller where the leading end F1 of the film comes into contact with the roller when the film enters is controlled to be <=60 deg.. Or, a track changing member 146 is arranged so that the leading end of the film can smoothly enter a nip part between the drum and the roller.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat developing apparatus for heat developing a heat developing material, and is particularly suitable for application to a medical image output apparatus.

[0002]

2. Description of the Related Art In order to thermally develop a heat developable film on which a latent image is formed by laser exposure or the like, the heat developable film is sandwiched between a heating drum and a plurality of rollers arranged around the drum and is rotated and conveyed. A heat developing device that heats while heating is known. In such an apparatus, the roller is biased toward the heating drum, and the film is pressed against the heating drum by the roller during thermal development.

However, when the film is conveyed to the heating drum and its leading end hits the first roller, the roller may float, which makes it difficult to evenly adhere the film to the outer peripheral surface of the heating drum. Therefore, uneven development may occur on the film. To prevent the floating of the roller, the biasing force of the roller with respect to the heating drum may be increased. However, foreign matter such as dust is caught between the films while the film is pressed against the outer peripheral surface of the heating drum by the large biasing force. If so, the film is likely to be scratched, which is not preferable.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems of the prior art, the present invention prevents the biasing roller from floating and makes the heating drum and the heat-developable film uniform without increasing the biasing force of the biasing roller. It is an object of the present invention to provide a heat developing apparatus capable of maintaining adhesion and preventing uneven development in a heat developed film.

[0005]

In order to achieve the above object, a first heat developing apparatus according to the present invention sends a heat developing film having a latent image to a heating member which is rotationally driven, and rotates with the heating member. In a heat developing apparatus for obtaining a visible image by heat developing by heating while conveying the heat developing film in a state of being sandwiched between a plurality of driven biasing members,
The urging member is urged to the heat developing film so as to have a pressure force of 7 gf / cm or less, and a film entry locus at the time of feeding the heat developing film to the heating member and a tip of the heat developing film are It is characterized in that the angle formed with the tangent line at the contact portion of the biasing member that abuts upon entering is 60 ° or less.

According to the first heat developing apparatus, the heat developing film enters at a relatively small angle of 60 ° or less with respect to the tangent line at the contact portion of the biasing member with which the leading end of the heat developing film contacts at the time of feeding. Thus, even if the heat-developable film comes into contact with the urging member at the time of entry, the urging member can be prevented from being lifted up. Therefore, the pressing force for pressing the heat-developable film against the heating member can be made relatively small at 7 gf / cm or less. Even if foreign matter such as dust is sandwiched between them, the film is not easily scratched. In this manner, the biasing member can be prevented from floating without increasing the biasing force of the biasing member, the uniform adhesion between the heating member and the heat-developable film can be maintained, and uneven development in the heat-developable film can be prevented.

In this case, a conveying member for feeding the heat-developable film to the heating member is placed in front of the heating member, and the relative position between the conveying member and the contact portion of the urging member and the feeding The angle can be adjusted by changing the direction.

The second heat developing apparatus according to the present invention is
By sending the heat-developable film having a latent image to a heating member that is driven to rotate, and heating the heat-developable film while conveying the heat-developable film while sandwiching it between the heating member and a plurality of biasing members that are driven to rotate. In the heat developing apparatus for obtaining a visible image by heat development, the biasing member is attached to the heat developing film.
The heating member is urged to have a pressure force of not more than gf / cm, and the conveying speed of the heating member is made higher than the conveying speed at the time of feeding the thermal development film to the heating member. It is characterized in that a trajectory changing member for changing the trajectory of the heat developing film is placed in front of the heating member so that the heat developing film can be smoothly fed.

According to the second heat developing apparatus, the heating member is conveyed faster than when the heat developing film is fed, and the trajectory changing member causes the heat developing film to flex smoothly between the heating member and the urging member. Because you can enter without generating
It is possible to prevent the biasing member from rising. Therefore, the pressure force for pressing the heat development film against the heating member is 7 gf / cm.
Since it can be made relatively small as follows, it is difficult for the film to be scratched even if foreign matter such as dust is sandwiched between them. In this way, uniform adhesion between the heating member and the heat-developable film can be maintained without increasing the urging force of the urging member, and uneven development in the heat-developable film can be prevented.

In this case, a conveying member for feeding the heat-developable film at the conveying speed at the time of feeding is placed in front of the heating member with respect to the heating member, and the trajectory changing member includes the conveying member and the heating member. It is preferable to be arranged between.

The third thermal development apparatus according to the present invention is
By feeding the heat-developable film having a latent image to a heating drum that is driven to rotate, and heating the heat-developable film while conveying the heat-developable film while sandwiching it between the heating drum and a plurality of biasing rollers that are driven to rotate. In a heat developing apparatus for obtaining a visible image by heat development, the urging roller is urged to the heat developing film so as to have a pressing force of 7 gf / cm or less, and the heating drum has a diameter within a range of 80 to 200 mm. Yes, the urging roller has a diameter within a range of 8 mm to 30 mm, and the tangential direction between the urging roller arranged on the most upstream side in the transport direction among the plurality of urging rollers and the heating drum. And the tangent line at the contact portion of the next urging roller with which the leading edge of the heat-developable film abuts, is set to 60 ° or less.

According to the third heat developing device, 80 to 2
A heating drum having a diameter of 00 mm and an urging roller having a diameter of 8 mm to 30 mm are used, and the heat-developable film is sent out from between the urging roller arranged on the most upstream side and the heating drum to contact the next urging roller. When the heat developing film comes into contact with the urging roller at the time of coming in, the heat developing film enters at a relatively small angle of 60 ° or less with respect to the tangent line at the contacting portion, The floating roller can be prevented from floating, and therefore the pressure force for pressing the heat-developable film against the heating drum can be made as small as 7 gf / cm or less, which makes it difficult to scratch the film even if foreign matter such as dust is sandwiched between them. . In this way, the biasing roller can be prevented from floating without increasing the biasing force of the biasing roller, the uniform adhesion between the heating drum and the heat developing film can be maintained, and uneven development in the heat developing film can be prevented.

The fourth heat developing apparatus according to the present invention is
By sending the heat-developable film having a latent image to a heating member that is driven to rotate, and heating the heat-developable film while conveying the heat-developable film while sandwiching it between the heating member and a plurality of biasing members that are driven to rotate. In a heat developing apparatus for obtaining a visible image by heat development, the urging roller arranged on the most upstream side in the transport direction among the plurality of urging rollers is composed of a stepped roller having a step at a longitudinal film passing portion. However, the stepped roller maintains the clearance between the heating member and the stepped roller at a constant level, and the stepped roller is biased by the heat developing film being conveyed so as not to be lifted up by the heating drum. It is characterized by being urged to.

According to the fourth heat developing apparatus, when the heat developing film passes through the clearance formed between the stepped biasing roller on the most upstream side and the heating member, the biasing roller floats up. In addition, since the clearance is maintained constant, uniform adhesion between the heating drum and the heat-developable film can be maintained, and uneven development in the heat-developable film can be prevented.

In this case, it is preferable that the clearance is set to be larger than the thickness of the heat developable film by 0.1 to 0.3 mm.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 is a front view of a heat developing apparatus according to an embodiment of the present invention, and FIG. 2 is a left side view of the heat developing apparatus. The heat developing apparatus 100 includes a feeding unit 110 that feeds the films F (photosensitive heat developing sheets) that are sheet-like photosensitive heat developing materials one by one, and an exposing unit 120 that exposes the fed films F. And a developing unit 130 for developing the exposed film F. Referring to FIGS.
The heat developing device 100 will be described.

In FIG. 2, the feeding unit 110 is provided in two stages, upper and lower, and the film F housed in the case C (see FIGS. 3 and 4).
For each case C is stored. The film F is taken out from the case C by a take-out device (not shown) and taken out in the direction (horizontal direction) shown by the arrow (1) in the figure. Further, the film F pulled out from the case C is transported in the direction (downward) indicated by the arrow (2) in the figure by the transport device 141 including the roller pair.

The film F conveyed below the heat developing apparatus 100 is further conveyed to the conveying direction changing section 145 located under the heat developing apparatus 100, and the conveying direction changing section 145 changes the conveying direction (see FIG. The arrow 2 (3) and the arrow (4) in FIG. 1 move to the exposure preparation stage. Further film F
From the left side surface of the heat developing device 100, as indicated by an arrow (5) in FIG.
In the direction (upward) shown in FIG.
2 conveys from the exposure unit 120 to the infrared region 780
Scanning exposure is performed with a laser beam L in the range of 860 nm, for example, a laser beam of 810 nm.

The film F receives the laser beam L to form a latent image in a manner described later. After that, the film F is conveyed in the direction (upward) shown by the arrow (6) in FIG. 1, and when it reaches the conveying roller pair 143, the drum 1 is kept as it is.
Supply to 4. That is, they are supplied at random timing. Further, it may be temporarily stopped at the time of arrival. In this case, the transport roller pair 143 has a function of determining the timing of supplying the film F to the drum 14 of the developing unit 130 that rotates at a constant rotation speed, and moves to the next supplied position on the circumference of the drum 14. The film F may be supplied onto the outer periphery of the drum 14 by starting the rotation of the pair of transport rollers 143 when the film F rotates. The specific configuration will be described later.

Further, the drum 14 rotates in the direction shown by the arrow (7) in FIG. 1 while holding the film F on the outer periphery of the drum 14. In this state, the film F is placed on the drum 1
4 is heated and thermally developed to form a visible image from the latent image in a manner described later. Thereafter, when the film F is rotated to the right side of FIG. 1, the film F is released from the drum 14,
1 is conveyed in the direction indicated by the arrow (8) and cooled, and then conveyed by the plurality of conveying roller pairs 144 in the direction indicated by the arrow (9) in FIG. To discharge.

FIG. 3 is a schematic diagram showing the structure of the exposure section 120. The exposure unit 120 deflects the laser light L, whose intensity is modulated based on the image signal S, by the rotary polygon mirror 113 to perform main scanning on the film F, and at the same time, scans the film F with respect to the laser light L in the main scanning direction. Sub-scanning is performed by relatively moving the film in a direction substantially perpendicular to and a latent image is formed on the film F by using the laser light L.

A more specific structure 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 in the D / A converter 122 and input to the modulation circuit 123. The modulation circuit 123, based on the analog signal,
The driver 124 of the laser light source unit 110A is controlled to emit the modulated laser light L from the laser light source unit 110A.

The laser light L emitted from the laser light source unit 110A passes through the lens 112 and then is converged only in the vertical direction by the cylindrical lens 115, and is rotated by the rotary polygon mirror 113 rotating in the arrow A direction in the figure. The light is incident as a line image perpendicular to the drive axis. The rotating polygon mirror 113 reflects and deflects the laser light L in the main scanning direction, and the deflected laser light L includes an fθ lens 114 including a cylindrical lens formed by combining two lenses.
After passing through, the light is reflected by a mirror 116 provided on the optical path extending in the main scanning direction, and is conveyed in the arrow Y direction (sub-scanning) by a conveying device 142 including a pair of conveying rollers. The surface 117 to be scanned of the film F is repeatedly main-scanned in the arrow X direction. That is, the laser light L
Is scanned over the entire surface 117 to be scanned on the film F.

The cylindrical lens of the fθ lens 114 allows the incident laser beam L to be scanned surface 117 of the film F.
Above, it is designed to converge only in the sub-scanning direction,
The distance from the fθ lens 114 to the surface to be scanned 117 is equal to the focal length of the entire fθ lens 114. As described above, in the main exposure unit 120, the fθ lens 114 including the cylindrical lens and the mirror 116 are arranged, and the laser beam L is rotated by the rotating polygon mirror 113.
As described above, since the light is converged only in the sub-scanning direction, the scanning position of the laser light L on the surface 117 to be scanned of the film F can be changed even if the rotary polygon mirror 113 is tilted or shakes. It is possible to form scanning lines of equal pitch without shifting in the sub-scanning direction.
The rotary polygon mirror 113 has an advantage that it is superior in scanning stability 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. still,
The specific content of the chemical reaction for forming the latent image will be described later with reference to FIG. 7.

FIGS. 4 to 6 are views showing the structure of the developing section 130 for heating the film F, more specifically, FIG. 4 is a perspective view of the developing section 140, and FIG. 7 is a perspective view schematically showing the end portions of the drum 14 and the roller 16 of the developing section, and FIG. 6 is a front view partially showing the upstream portion of the drum 14 and the roller of the developing section.

The developing section 130 has a drum 14 as a heating member capable of heating while holding the film F in close contact with the outer periphery. The 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 minimum heat development temperature or higher for a predetermined heat development time. Here, the lowest heat development temperature is the lowest temperature at which the latent image formed on the film F begins to be heat developed, and is 100 ° C. or higher in the film of the present embodiment. On the other hand, the heat development time means a time that should be maintained at the minimum heat development temperature or higher in order to develop the latent image of the film F to a desired development characteristic. The film F is preferably one which is not substantially thermally developed at 40 ° C. or lower. The specific contents of the chemical reaction for visualizing the latent image by heating will be described later with reference to FIG.

In the present embodiment, the developing unit 130 is incorporated in the thermal developing device 100 together with the exposing unit 120, but it may be a device independent of the exposing unit 120. In such a case, it is preferable that there is a transport unit that transports the film F from the exposure unit 120 to the developing unit 130.

Outside the drum 14, 16 to 20 small-diameter rollers 16 are provided as guide members and urging members, which face the drum 14 in parallel and are arranged in the circumferential direction of the drum 14, etc. It is arranged at intervals. At both ends of the drum 14, three guide brackets 21 supported by the frame 18 are provided on each side. In addition, by combining the guide brackets 21, opposing C-shapes are formed at both ends of the drum 14.

Each guide bracket 21 has nine elongated holes 42 extending in the radial direction. The shafts 40 provided at both ends of the roller 16 project from the elongated holes 42. One end of the coil spring 28 is attached to each of the shafts 40, and the other end of the coil spring 28 is attached near the inner edge of the guide bracket 21. Therefore, each roller 16 is biased to the outer periphery of the drum 14 by a predetermined force based on the biasing force of the coil spring 28. When the film F enters between the outer periphery of the drum 14 and the roller 16, the film F is pressed against the outer peripheral surface of the drum 14 by the predetermined force, thereby uniformly heating the film F over the entire surface.

Shaft 2 coaxially connected to drum 14
2 extends outward from the end member 20 of the frame 18 and is rotatably supported by the shaft bearing 24 with respect to the end member 20. A gear (not shown) is provided on the rotary shaft 23 of the micro step motor 26 arranged below the shaft 22 and attached to the end member 20.
Are formed. On the other hand, a gear is also formed on the shaft 22. The power of the micro step motor is transmitted to the shaft 22 via a timing belt (belt in which gears are engraved) 25 connecting both gears, and the drum 14 is thereby rotated. The rotary shaft 23 to the shaft 2
The power may be transmitted to the gear 2 via a chain or a gear train instead of the timing belt.

As shown in FIG. 1, in the present embodiment, the roller 16 is approximately 170 in the circumferential direction of the drum 14.
It is provided over an angular range of degrees. A plate-shaped heater is attached to the inner circumference of the drum 14 over the entire circumference to heat the outer circumference of the drum 14. The diameter of the drum 14 is in the range of 80 to 200 mm.

The drum 14 is provided with a support tube made of aluminum and a soft flexible layer (elastic layer) attached to the outside of the support tube. The flexible layer may be indirectly attached to the support tube. The unevenness of the wall thickness of the support tube is preferably within 4%, for example. Further, the flexible layer has a sufficiently smooth surface in order to enhance the adhesion to the film F to be heated, and its surface roughness Ra is 5 μm (particularly 2 μm).
It is desirable that it is smaller than m).

However, in order to prevent the film F from sticking to the drum 14, the surface roughness Ra of the specific material such as silicon rubber is as follows.
It is better to set it to 0.3 μm or more. When the surface roughness Ra is 0.3 μm or more, gas, particularly volatile material, is easily discharged from between the flexible layer and the film F.

Since the flexible layer is used, the film F is more surely brought into close contact with the drum 14 by the roller 16 without sacrificing abrasion resistance.
The soft layer has a Shore A hardness of 7 as measured by a durometer.
It is preferably 0 or less (particularly 60 or less). In the present embodiment, the Shore A hardness measured by a durometer is 55 or less.

Certain materials contain additives to enhance thermal conductivity and silicone rubber, and such materials have been found to be particularly beneficial for forming flexible layers. There is. Although the silicon rubber contained in such a material has a relatively low thermal conductivity, the silicon rubber improves the pressing performance of the film F and the durability (wear resistance) to the film F.

On the other hand, in order to improve the processing capacity of development, it is necessary to increase the thermal conductivity, but the additives in the above-mentioned materials contribute to maintaining the high thermal conductivity. Is. However, in the material forming the flexible layer, when the additive amount of the additive is increased, the pressing performance and durability by the silicone rubber are deteriorated. Therefore, the additive amount of the additive and the silicone rubber are balanced within a certain range. There is a need. The material containing silicon rubber is
It has the advantage that it is easily released from the film F and is chemically inert.

The thickness of the flexible layer is preferably in the range of 0.1 mm to 2 mm, and it is possible to use a flexible layer thinner than this, but as the thickness becomes thinner, the function of the flexible layer deteriorates. However, there is a problem that its manufacture becomes difficult. Therefore, the thickness of the flexible layer is preferably 0.4 mm or more. Further, it is preferable that the variation in the thickness of the flexible layer is 20% or less (particularly 10% or less) on the surface region. In the present embodiment, it is suppressed to 5% or less.

In this embodiment, a rotatable roller 16 is used as the guide member. However, it is also possible to use other means such as a small movable belt. In the present embodiment, the outer diameter of the roller 16 is in the range of 8 to 30 mm and the wall thickness is 2 mm.
Use an aluminum tube.

As described above, the urging force of the coil spring 28 determines the pressing force of the roller 16 so that the film F can be more firmly attached to the outer peripheral surface of the drum 14 and can receive sufficient heat transfer. Therefore, it is necessary to be careful when selecting the value. If the biasing force of the coil spring 28 is too small, heat is non-uniformly conducted to the film F, which may result in incomplete image development. Therefore, the biasing force from the roller 16 per 1 cm of the width of the film F is 3 g.
It is preferably f or more (particularly 5 gf or more). Further, when the film F is rotationally moved together with the drum 14 and the roller 16 is in contact with the film F, the film F
May be damaged by the roller 16. Therefore, the biasing force of the coil spring 28 needs to be small enough to prevent the roller 16 from making an indentation on the film F.

Therefore, it is desirable that the urging force from the roller 16 per cm of the width of the film F is between 3 and 7 gf per cm of the width of the film F. As a result, even if foreign matter such as dust is sandwiched between the rollers 16, no indentation is generated on the film F. In addition, each coil spring 28
Is a roller 16 provided around the cylindrical drum 14.
When used for, the biasing force of each coil spring 28 is
It may be determined in consideration of the gravity acting on each roller 16. For example, the roller 16 located above the drum 14
The coil spring 28 for urging the roller 16 is more than the coil spring 28 for urging the roller 16 on the bottom side of the drum 14.
By making the biasing force smaller depending on the weight of the roller 16, almost the same surface pressure can be applied to the entire film F.

In addition to the force exerted by each roller 16, the space between adjacent rollers 16 is important for high quality image formation on film F. When the film F is supplied to the drum 14,
The temperature is generally room temperature (approximately 20 ° C). Therefore, in order to maximize the processing capacity of the developing unit 130,
Film F must be rapidly heated from room temperature to the minimum heat development temperature required to initiate development.

However, a support (base material) contained in a certain type of film F, for example, a plate material having a polyester film as a base and other thermoplastics (materials)
There is a risk that the plate material having a base of will thermally expand or contract (shrink) during heating. Therefore, in order to make the dimensional change uniform so that wrinkles (folds) are not formed,
The film F must be heated uniformly when it alternates between being held flat and unconstrained. To achieve this,
The plurality of rollers 16 allow the change of the area (area) of the film F located between the adjacent rollers 16 when the film F is not constrained between the roller 16 and the drum 14. , Provided at intervals.

Further, as described above, in order to conduct heat sufficiently and uniformly to develop the film F uniformly, the roller 16 holds the film F for a predetermined time in a state of being urged against the drum 14. Must. As a result, the space located between adjacent rollers 16 is
Film F to minimize wrinkles
The heating should be selected so that it can be done quickly and uniformly.

Further, on the outer periphery of the cylindrical drum 14,
The rigidity of the film F itself causes its leading edge to extend in the tangential direction of the nip portion between the rollers 16, but the rollers 16 must be sufficiently close to each other in order to suppress this. Such an arrangement is important for holding the film F between the roller 16 and the drum 14.

Further, as shown in FIG. 5, gear teeth 14a are provided at both ends of the drum 14 as rotation driving portions of the rollers, and gear teeth 16a are provided at both ends of each roller 16 as rotation driven portions. Tooth 14a and gear tooth 16a
Is in mesh with. As a result, each roller 16 is rotationally driven in synchronization with the rotation of the drum 14 via the gear teeth 16a of the driven portion, and is rotated without receiving a driving force from the film F, so that the rollers 16 do not stop. It is possible to prevent uneven development due to stoppage.

As shown in FIGS. 1, 4, and 5, for example, 2
The zero rollers 16 are provided over about 171 degrees in the rotation direction of the drum 14, and each space is separated from the center by about 9 degrees. This configuration
When the drum 14 has a diameter of 15 cm to 30 cm and the roller 16 has a diameter of 1 to 2 cm, a film having a base thickness of 0.1 to 0.2 mm, for example, a support having a thickness of 0. A film having a relatively hard film F, such as a 18 mm polyester film, or a base having a thickness of 0.1
It effectively acts on a film F having a smaller hardness, such as a polyester film having a thickness of 0 mm.

A heater is attached to the inner periphery of the drum 14 to heat the outer peripheral surface of the drum 14. The heater for heating the drum 14 may be, for example, an etched resistive foil heater. Drum 1
In accordance with the temperature information detected by the temperature sensor provided in the drum 4, the electric power supplied to the heater is adjusted so that the temperature suitable for the development of the specific film F is obtained.
The outer surface temperature of 4 is adjusted. In the present embodiment, the drum 14 can be heated to a temperature of 60 ° C. to 160 ° C., and if the temperature in the width direction of the drum 14 is maintained within 2.0 ° C. (particularly within 1.0 ° C.). Preferably, in this embodiment, it is maintained within 0.5 ° C.

Further, as shown in FIGS. 1 and 4, the drum 1
4 is arranged on the upstream side (the lower side in the drawing), and the conveying roller pair 143 for feeding the film F toward the drum 14 of the developing unit 130 has one roller rotatably driven by the motor 151, and the motor 151 controls the motor 151. It is controlled by 150, and the timing and speed of its rotation are controlled.

As shown in FIG. 6, the undeveloped film F supplied from the conveying roller pair 143 toward the drum 14 at a predetermined timing under the control of the controller 150 approaches the drum 14 from below in FIG. The leading edge F1 of the film is fed into contact with the most upstream roller 16 _1, and the tangent line a at the contact portion b on the outer peripheral surface of the roller 16 _{1 at} this time
The relative position and the transport direction of the transport roller pair 143 and the roller 16 ₁ are adjusted so that the angle θ1 between the track and the trajectory of the film F is 60 degrees or less. Specifically, the positions of the transport roller pair 143 in the vertical direction and the horizontal direction in FIG. 6 are adjusted, and the tangential direction of the nip portion of the transport roller pair 143 is adjusted.

As described above, when the leading edge F1 of the film abuts the roller 16 ₁ on the most upstream side and the angle θ1 is too large, the roller 16 ₁ floats away from the outer peripheral surface of the drum 14 and the film F is had happen that no close contact with the drum 14, but by such an angle θ1 relatively small as 60 degrees or less, the direction in which float the rollers 16 _one of the contact force produced by the contact of the film It is possible to reduce the components, prevent the film from floating, and prevent the film F from uniformly sticking to the drum 14 and causing uneven development. As described above, the biasing force from the roller 16 is preferably a relatively small value such as 7 gf / cm or less in order to prevent scratches such as indentations on the film F, whereas in the conventional technique, when the biasing force is small, Although the roller becomes easier to float, according to the present embodiment, the urging force from the roller 16 is 7 gf /
Even if it is relatively small as cm or less, lifting of the roller can be effectively prevented.

Next, the leading edge F1 of the film is attached to the roller 16
₁ is guided by the rotation of ₁ to enter the nip portion 52 formed with the drum 14, and when it exits from the nip portion 52, it returns linearly due to the rigidity of the film F as described above, and the tangent e of the nip portion 52 advances in the direction, but in contact with the next roller 16 _2, the film F after exiting the tangent c in abutment d on the outer peripheral surface of the roller 16 ₂ at this time, from the tangent e (nip 52
The angle θ2 with respect to (the locus) is 60 degrees or less. Specifically, as described above, it can be adjusted by changing the distance between the rollers 16 ₁ and 16 ₂ . Thus, in the same manner as described above can be prevented from rising of the next roller 16 _2, it can prevent the occurrence of uneven development.

As described above, the film F is urged against the drum 14 by the plurality of rollers 16,
Although the drum 14 moves around the drum 14 as it rotates, the drum 14 is uniformly heated for a predetermined time while being brought into contact with the outer peripheral surface of the drum 14, and is thermally developed without causing uneven development. Specifically, for example, when developing a film F coated with PET (polyethylene terephthalate) as a support having a photosensitive thermal development emulsion containing infrared-sensitive silver halide of 0.178 mm, the drum 14 is used.
Is rotated at a rotation speed such that the outer peripheral surface is maintained at 120 ° C. and the film F is held in contact with the outer peripheral surface for a predetermined time of about 15 seconds. The film F is raised to a temperature of 120 ° C. for the predetermined time and the temperature. The glass transition temperature of PET is about 80.
℃. Further, the surface of the film F on the side having the photosensitive heat-developable emulsion layer is preferably in contact with the outer peripheral surface of the drum 14 (the flexible layer in the present embodiment).

FIG. 7 is a cross-sectional view of the film F shown in the example, and is a diagram schematically showing the chemical reaction in the film F during exposure. FIG. 8 is a sectional view similar to FIG. 7, schematically showing the chemical reaction in the film F during heating. In the film F, a photosensitive layer containing a heat-resistant binder as a main component is formed on a support (base layer) made of PET, and a protective layer containing a heat-resistant binder as a main component is further formed thereon. The photosensitive layer contains silver halide grains and silver behenate (Beh. Ag), which is a type of organic acid silver.
And a reducing agent and a toning agent. In addition, a back surface layer containing a heat resistant binder as a main component is also provided on the back surface of the support.

When the film F is irradiated with the laser beam L from the exposure section 120 during the exposure, as shown in FIG.
Silver halide grains are exposed to the area irradiated with the laser beam L, and a latent image is formed. On the other hand, when the film F is heated to the minimum heat development temperature or higher as described above, silver ions (Ag ⁺ ) are released from silver behenate, and the behenic acid that released the silver ions is adjusted as shown in FIG. Forms a complex with the colorant. It is believed that the silver ions then diffuse and the reducing agent acts with the exposed silver halide grains as nuclei to form a silver image by a chemical reaction. Film F
Contains a photosensitive silver halide grain, an organic silver salt, and a silver ion reducing agent, and is not substantially thermally developed at a temperature of 40 ° C. or lower, and at a temperature of a minimum development temperature of 80 ° C. or higher. It is heat-developed.

Next, a modification of this embodiment shown in FIG. 6 will be described with reference to FIG. In the example of FIG. 9, a pair of conveyance rollers 1
43 and a roller 16 ₁ on the most upstream side, a roller-shaped locus changing member 146 is provided so as to change the locus of entry of the film F toward the drum 14 and the roller 16 ₁ , and the conveying speed of the drum 14 is set. V0 is controlled to be higher than the transport speed V1 of the transport roller pair 143. Trajectory change member 146 is arranged at a position to smoothly enter the nip portion 52 between the tip F1 is the drum 14 and the roller 16 ₁ of the film.

According to the structure of FIG. 9, the drum 14 is conveyed faster than when the film F is fed, and the trajectory changing member 14 is moved.
6 allows the film F to smoothly enter the nip portion 52 without causing bending or the like, so that the roller 16 ₁ can be prevented from rising. For this reason, the pressing force for pressing the film against the drum 14 can be made as small as 7 gf / cm or less, so that the film is unlikely to be scratched even if foreign matter such as dust is sandwiched therebetween. In this way, uniform adhesion between the drum 14 and the film F can be maintained without increasing the biasing force of the roller,
It is possible to prevent uneven development in the film.

Next, another modification of FIG. 6 will be described with reference to FIGS. In the example of FIG. 10, the roller 16 ₁ on the most upstream side is a stepped roller, and the film F passes through the clearance formed between the roller 14 1 and the drum 14. As shown in FIGS. 10 and 11, the roller 16 ₁
Has a small diameter portion 148 having a length slightly larger than the film width w, forms a clearance 149 between the small diameter portion 148 and the drum 14, and the film F has a clearance 149.
Even if the elastic force of the film F is applied to the roller 16 ₁ when passing through, the drum 14 is applied with a constant biasing force so that the roller 16 ₁ does not float up.

Specifically, the coil spring 28 shown in FIG. 4 can be prevented from being lifted by adjusting the spring constant of the coil spring 28 to set a relatively large biasing force. In this case, even greater biasing force to the roller 16 ₁ and does not participate in the film, does not occur scratching problems indentations or the like in the film. Further, since the clearance 149 urging force in the diameter and the roller 16 ₁ of the small diameter portion 148 is determined such 0.1~0.3mm larger than the thickness of the film F, the clearance 149 is relatively small, the film F It can be brought into close contact with the drum 14.

According to the configurations of FIGS. 10 and 11, when the film F passes through the clearance 149, the roller 14 does not float and the clearance 149 is maintained constant, so that the drum 14 and the film F are evenly adhered. The property can be maintained, and uneven development in the film can be prevented.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited thereto.
Various modifications are possible within the scope of the technical idea of the present invention. For example, the constituent materials of the drum and the roller are not limited to those of this embodiment, and it goes without saying that other materials may be used. Further, although the developing unit 130 is incorporated in the thermal developing device 100 together with the exposing unit 120 in the present embodiment, it may be configured separately from the exposing unit 120. In such a case, a transport unit that transports the film F from the exposure unit 120 to the developing unit 130 is required.

[0061]

According to the heat developing apparatus of the present invention, the biasing member is prevented from floating from the heating member, and the heating member and the heat developing film are made uniform without increasing the biasing force of the biasing member. It is possible to maintain the adhesiveness and prevent uneven development in the heat developable film.

[Brief description of drawings]

FIG. 1 is a front view of a heat developing apparatus according to an embodiment of the present invention.

FIG. 2 is a left side view of the heat developing device according to the embodiment of the present invention.

FIG. 3 is a schematic diagram showing a configuration of an exposure unit 120 in the heat developing apparatus of FIG.

4 is a diagram showing a configuration of a developing section 130 for heating the film F in the heat developing apparatus of FIG. 1, and is a perspective view of the developing section 130. FIG.

5 is a perspective view schematically showing the drum 14 and the roller 16 of the developing unit 130 in the heat developing apparatus of FIG.

6 is a front view partially showing an upstream portion of a drum 14 and a roller 16 of a developing section 130 in the heat developing apparatus of FIG.

FIG. 7 is a cross-sectional view of film F, schematically showing the chemical reaction in film F during exposure.

8 is a sectional view similar to FIG. 7, schematically showing the chemical reaction in the film F during heating.

9 is a diagram showing a modification of FIG. 6 of the present embodiment,
It is a front view which shows the upstream part of the drum 14 and the roller 16 partially.

10 is a diagram showing another modification of FIG. 6 of the present embodiment, and is a perspective view showing a drum 14 and a roller 16. FIG.

FIG. 11 is a plan view showing the main parts of the modification of FIG.

[Explanation of symbols]

14 Drum (heating member) 16 Roller (urging member) 16 ₁ Roller 16 on the most upstream side ₂ Roller 100 arranged next to the most upstream roller 16 ₁ Thermal developing device 110 Storage section 120 Exposure section 130 Developing section 143 Conveying roller pair 146 Trajectory changing member 148 Small diameter portion 149 of stepped roller Drum and small diameter portion 148
Clearance F film (heat development film) a tangent line c at the contact portion b of the roller 16 ₁ tangent line θ ₁ at the contact portion c of the roller 16 ₂ angle θ 2 tangent line between the tangent line a and the entry path of the film angle between b and tangent e

Claims (7)

[Claims] 1. A heat-developable film having a latent image is fed to a heating member that is driven to rotate, and the heat-developable film is conveyed while being sandwiched between the heating member and a plurality of biasing members that are driven to rotate. In the heat developing apparatus for heat-developing to obtain a visible image by heating while heating, the biasing member is biased to the heat developing film so as to have a pressing force of 7 gf / cm or less, and the heat developing film with respect to the heating member. The angle formed between the film entry locus at the time of feeding and the tangent line at the contact portion of the biasing member with which the leading end of the heat development film abuts at the time of entry is set to 60 ° or less. And thermal development equipment. 2. A conveying member for feeding the heat-developable film to the heating member is placed in front of the heating member, and the relative position between the conveying member and the contact portion of the urging member and the feeding direction. The thermal developing apparatus according to claim 1, wherein the angle is adjusted by changing the angle. 3. A heat-developable film having a latent image is sent to a heating member that is rotationally driven, and the heat-developable film is conveyed while being sandwiched between the heating member and a plurality of biasing members that are rotationally driven. In a heat developing apparatus for obtaining a visible image by heat developing while heating, the urging member is urged to the heat developing film so as to have a pressing force of 7 gf / cm or less, and the conveying speed of the heating member is set to the above. The heating member is a locus changing member that is faster than the conveying speed of the heat developing film with respect to the heating member and changes the locus of the heat developing film so that the heat developing film can be smoothly fed into the heating member. A heat developing device characterized in that it is placed in front of. 4. A transport member for feeding the heat-developable film at the transport speed at the time of feeding is placed in front of the heating member with respect to the heating member, and the trajectory changing member connects the transport member and the heating member. The thermal development device according to claim 3, wherein the thermal development device is disposed between the thermal development devices. 5. A heat-developable film having a latent image is sent to a rotatably driven heating drum, and the heat-developable film is conveyed while being sandwiched between the heat-drum and a plurality of urging rollers rotatably driven. In the heat developing device for heat-developing to obtain a visible image by heating while heating, the biasing roller is biased to the heat developing film so as to have a pressing force of 7 gf / cm or less, and the heating drum has a diameter of 80 to Within the range of 200 mm, the diameter of the biasing roller is within the range of 8 mm to 30 mm, and the biasing roller and the heating drum that are arranged on the most upstream side in the transport direction among the plurality of biasing rollers. And the tangent to the contact portion of the next urging roller with which the leading edge of the heat developing film abuts, the angle formed by the tangent is between 60 ° and 60 ° or less. Dress . 6. A heat-developable film having a latent image is sent to a heating member that is rotationally driven, and the heat-developable film is conveyed while being sandwiched between the heating member and a plurality of biasing members that are rotationally driven. In a heat developing apparatus that obtains a visible image by performing heat development while heating, the urging roller arranged on the most upstream side in the transport direction among the plurality of urging rollers has a step in the longitudinal film passing portion. A stepped roller, wherein the stepped roller maintains a constant clearance between the heating member and the stepped roller and prevents the stepped roller from being lifted by the heat-developable film being conveyed. A thermal developing device, wherein the heating drum is biased by a force. 7. The heat developing apparatus according to claim 6, wherein the clearance is set to be larger than the thickness of the heat developing film by 0.1 to 0.3 mm.