JP2000347379A - Heat developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developing device which is capable of uniformly heating a photosensitive heat developable material. SOLUTION: The surface stock of a belt 6b of a belt drive assembly 6 of a heat developing section 200C is formed of a nonwoven fabric and the thermal conductivity of tubes of revolving rollers 4 is specified to <=0.2 W/(m.K). Further, in a preheating section 200C, transporting rollers 14 and 16 preheat the belt while holding the belt with nip parts at >=2 points. In addition, the thermal conductivity of the surface stock of the revolving rollers 4 is specified to >=1.0 W/(m.K).

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 heating and thermally developing a sheet-shaped exposed photosensitive heat developing material.

[0002]

2. Description of the Related Art In U.S. Pat. No. 5,352,863, it is described that a heat development material is heated while being conveyed by three or more rollers supporting the heat development material in an oven as a heat development unit. . No. 5,869,806.
And U.S. Pat. No. 5,869,807 describe preheating while thermally bending a heat-developable material with rollers arranged in a staggered manner.

[0003]

However, in these conventional techniques, it was difficult to control the temperature of the heat developing section. Also. Temperature distribution unevenness was easily generated, and density unevenness was easily generated. In particular, in a thermal developing apparatus for forming a newspaper plate or the like, there is a situation in which the demand for density unevenness is severe. Further, it took a long time until the temperature of the heat developing section reached a predetermined developing temperature after the apparatus was started.

The inventor of the present invention has intensively studied this phenomenon, and has found the following causes. That is, in the heat development device of the related art, three or more rollers are provided to support the heat development material from below. However, since there is a large space above the conveyed heat development material, outside air flows into such space. In some cases, air may easily flow through the space. As a result, it is difficult to control the temperature of the heat developing section, and temperature distribution unevenness is likely to occur,
As a result, density unevenness is likely to occur, and it is considered that the time from when the apparatus is started up to when the temperature of the thermal developing section reaches a predetermined developing temperature becomes longer.

SUMMARY OF THE INVENTION The present invention has been made in view of these problems, and is intended to reduce unevenness in density and to reduce the time required for the temperature of the heat developing section to reach a predetermined developing temperature after starting up the apparatus. An object is to provide a developing device.

[0006]

Means and means for solving the problems will be described below. (1) The thermal developing device of the present invention includes a connecting portion for supplying a sheet-shaped exposed photosensitive thermal developing material, and a thermal developing material supplied from the supplying portion along a substantially horizontal transport path. A pre-heating unit for pre-heating while transporting; a thermal developing unit for heating and thermally developing the thermally-developed material preliminarily heated by the pre-heating unit while transporting the material along a substantially horizontal transport path; A cooling section for cooling the heat-developable material thermally developed in the heat-development section while transporting the heat-developable material; In the pre-heating unit, a transport roller is provided so that the nip portion sandwiching the transport path is at two or more places, and the thermal developing unit is configured to perform the thermal development from below the transport path. A transport belt for transporting and supporting the thermal developing material; Wherein the surface material of the conveyor belt is a non-woven fabric, and the thermal conductivity of the surface material of the roller is in a thermal developing apparatus having two or more rotary rollers provided so as to sandwich the transport path facing the belt. Is 0.2W
/ (M · K) or more and 1.0 W / (m · K) or less. Therefore, the surface material of the conveyor belt of the heat developing unit is a nonwoven fabric, and the thermal conductivity of the surface material of the rotating roller is 0.2 W / (m
・ K) or less, so that a heat insulating space can be formed between the sheet and the conveyance roller, and since the space other than the conveyance path can also have heat insulation, it becomes difficult for air to flow,
The temperature of the heat developing section can be controlled relatively easily.
Further, heat conduction with the surroundings can be suppressed, the temperature distribution in the transport path of the heat developing section can be easily made uniform, fluctuations in the heat developing temperature due to fluctuations in the surrounding temperature can be suppressed, and further, in the preheating section, Since the conveying roller preheats while being sandwiched between two or more nip portions, the heat development property of the photosensitive heat development material is improved, and thereafter, heat development is performed in the heat development section, so that the heat development section can be small, It is easy to suppress the temperature unevenness in the heat developing section. In addition, since the thermal conductivity of the surface material of the rotating roller is 1.0 W / (m · K) or more, the heat developing material is heated to the heat developing temperature in a short time to a predetermined temperature. Time thermal development can be performed.

(2) Further, the conveyor belt has a structure in which a nonwoven fabric is provided on the surface side of a belt-shaped support, and the thermal conductivity of the belt-shaped support is 0.2 W / (m · K). More than 10
If it is W / (m · K) or less, the thermal conductivity of the belt-like support is 0.2 W / (m · K) or more. The density unevenness of the heat developing material is suppressed, and the heat conductivity of the belt-shaped support is 0.2 w / (m · K) or less, so that heat hardly escapes to the surroundings, and after the apparatus is started. The time required for the temperature of the heat developing section to reach the predetermined developing temperature can be shortened.

(3) Further, if the specific electrical resistance of the surface material of the rotating roller is 10 ¹⁴ Ωm or less and the specific electrical resistance of the belt-shaped support is 10 ¹⁴ Ωm or less, Even if static electricity is generated between the rotating roller and the heat developing material when the material is a non-woven fabric, the specific electrical resistance of the surface material of the rotating roller is as low as 10 ¹⁴ Ωm or less, and the specific electrical resistance of the belt-shaped support is 10 ¹⁴ Ωm. Since it is as low as below, static electricity hardly accumulates and discharge to the heat developing material can be suppressed.

(4) Further, if the specific heat of the surface material of the rotary roller is 1.5 J / (K · g) or more, heat is deprived by the heat developing material, and the surface temperature of the rotary roller rapidly decreases. Therefore, it is possible to prevent the heat development temperature of the heat development material conveyed later from lowering, to perform stable heat development, and to suppress the occurrence of density unevenness.

(5) Further, if the variation in the surface temperature of the rotating roller during thermal development is 2 ° C. or less, the variation in the temperature of the rotating roller is small, so that the density unevenness due to the temperature unevenness can be suppressed.

(6) Further, the distance L (mm) between the centers of the adjacent rotating rollers and the diameter D (m) of the rotating rollers
m) satisfies the following formula: 50 ≦ L ≦ 200 20 ≦ D ≦ 50 30 ≦ LD ≦ 150 Suppressing the rise of the heat developing material from the conveying belt and conveying the heat developing material along a stable route The density unevenness due to the deflection of the conveyance can be suppressed, and since there is no large space above the conveyance belt, the air does not easily flow, so that the temperature of the thermal developing unit can be controlled relatively easily. Thermal conduction with the surroundings can be suppressed, the temperature distribution in the transport path of the heat developing section can be easily made uniform, fluctuations in the heat developing temperature due to fluctuations in the surrounding temperature can be suppressed, and component costs and manufacturing costs can be reduced. Can be lowered.

(7) The heat developing apparatus of the present invention comprises: a supply section for supplying a sheet-shaped exposed photosensitive thermal development material; and a heat development material supplied from the supply section along a substantially horizontal conveyance path. A pre-heating unit for pre-heating while transporting, and a heat developing unit for heating and thermally developing the heat-developable material pre-heated by the pre-heating unit while being transported along a substantially horizontal transport path. The heat-developable material heat-developed in the heat-development unit is
And a cooling unit for cooling while transporting, wherein the thermal development unit thermally develops at a predetermined thermal development temperature equal to or higher than a minimum thermal development temperature at which the thermal development material is thermally developed, and in the preheating unit,
So that the nip portion sandwiching the transport path is at two or more places,
A transport roller is provided, and in the thermal developing section, a transport belt that transports the thermal development material while supporting the thermal development material from below the transport path, and sandwiches the transport path in opposition to the transport belt. In the thermal developing device having two or more rotating rollers provided in the above, a center distance L (mm) between adjacent rotating rollers and a diameter D (mm) of the rotating rollers
Satisfies the following formula: 50 ≦ L ≦ 200 20 ≦ D ≦ 50 30 ≦ LD ≦ 150 Suppression of the heat development material from the conveyance belt is suppressed, and the heat development material can be conveyed along a stable path. The unevenness of the density due to the bending of the belt is suppressed, and since there is no large space above the conveyor belt, the air does not easily flow, so that the temperature of the heat developing unit can be controlled relatively easily, and The heat conduction can be suppressed, the temperature distribution in the conveyance path of the heat development section can be easily made uniform, and the fluctuation of the heat development temperature due to the fluctuation of the ambient temperature can be suppressed. Pre-heating while nipping at more than two nips improves the heat developability of the photosensitive heat-developable material. Easy to control unevenness In addition, the heat development material can be heated to the heat development temperature in a short time to perform the heat development for a predetermined time, and the parts cost and the manufacturing cost can be reduced.

(8) Further, the pressure between the transfer rollers is 15 g / sq. Cm to 40 g / sq. Cm, and the pressure between the rotating roller and the transfer belt is 0 g / sq.
Since it is not less than g / square cm and not more than 40 g / square cm, it is possible to further improve the heat developability of the photosensitive heat-developable material and to suppress the occurrence of indentations and pressure fogging on the heat-developable material.

(9) The thermal developing apparatus of the present invention comprises a supply section for supplying a sheet-shaped exposed photosensitive thermal developing material, and a substantially horizontal conveying path for supplying the thermal developing material supplied from the supplying section. A pre-heating section for pre-heating while removing along the heat-development section, and a thermal development for heating and thermally developing the heat-developable material pre-heated by the pre-heating section while being transported along a substantially horizontal transport path. And a cooling unit that cools the heat development material that has been heat-developed in the heat development unit while transporting the heat development material, wherein the heat development unit is at least the lowest heat development temperature at which the heat development material is thermally developed. A heat roller is provided so that the heat development is performed at a predetermined heat development temperature, and the nip portion sandwiching the conveyance path is provided at two or more places in the preheating section. A transfer belt that transfers the heat development material while supporting it from below And two or more rotating rollers provided so as to sandwich the conveyance path opposite to the conveyance belt, wherein a pressure between the rollers of the conveyance roller pair is 15 g / cm 2 or more and 40 g or more. / Square cm
Since the pressure between the rotating roller and the conveyor belt is 0 g / square cm or more and 40 g / square cm or less, there is no large space above the conveyor belt, so that air does not easily flow. The temperature of the heat developing section can be controlled relatively easily, the heat conduction with the surroundings can be suppressed, the temperature distribution in the transport path of the heat developing section can be easily made uniform, and the temperature of the heat developing In the preheating section, the transport roller preheats while sandwiching it at two or more nips, so that the heat developability of the photosensitive heat developing material is improved. Since the heat development is performed in the heat development section, the heat development section can be small, temperature unevenness in the heat development section can be easily suppressed, and the heat development material can be heated to the heat development temperature in a short time to perform the heat development for a predetermined time. While the photosensitive heat While further improving the thermal development of image materials, it is possible to suppress the occurrence of fogging indentation and pressure to thermally developable materials.

(10) Further, the speed of transporting the heat developing material from the supply unit to the preheating unit, the speed of transporting the heat developing material in the preheating unit and the heat developing unit, and the speed of the heat developing unit And the transfer speed to the cooling unit are substantially the same transfer speed and 1 cm / sec or more and 3 cm / sec or less. It can sufficiently cope with heat taken out by the developing material, can stabilize the heat development temperature, and can suppress density unevenness.

(11) Further, the heat-developable material 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 less,
Since heat development is performed at a temperature not lower than the minimum development temperature of 80 ° C. or higher, heat development is not substantially performed at room temperature, and thus a heat-developed image can be stored for a long period of time.

(12) Further, the thermal developing section thermally develops the thermal developing material at a thermal developing temperature equal to or higher than the minimum developing temperature for a predetermined thermal developing time. Since the heating is performed to a temperature equal to or lower than the minimum thermal development temperature, more favorable thermal development can be performed.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention, which are examples of the present invention, will be described. Therefore, the meaning of the terms of the invention and the invention itself should not be construed as being limited by the description of the embodiments of the invention, and it is needless to say that the invention can be appropriately changed / improved.

The heat developing apparatus of the present invention has a function of developing a photosensitive material on which a latent image is formed by being exposed by irradiating a laser beam or the like with an exposure apparatus including a laser diode. FIG. 1 is a diagram showing a schematic configuration of the exposure apparatus 100.

The exposure apparatus 100 deflects the laser light L whose intensity has been modulated based on the image signal S by the rotary polygon mirror 113 to perform main scanning on the film F, and simultaneously scans the film F with respect to the laser light L. Sub-scanning is performed by relatively moving in a direction substantially perpendicular to the scanning direction, and a latent image is formed on the film F using the laser light L.

A more specific configuration will be described below. In FIG. 1, an image signal S which is a digital signal output from an image signal output device 121 is converted into an analog signal by a D / A converter 122 and input to a modulation circuit 123. The modulation circuit 123, based on the analog signal,
The driver 124 of the laser light source unit 110 is controlled to emit the modulated laser light L from the laser light source unit 110.

The laser light L emitted from the laser light source unit 110 passes through a collimator lens 112 and is converged only in a vertical direction by a cylindrical lens 115. The laser light L is applied to a rotating polygon mirror 113 which rotates in the direction of arrow A in FIG. The light is incident as a line image perpendicular to the drive shaft.
The rotating polygon mirror 113 reflects and deflects the laser light L in the main scanning direction, and the deflected laser light L is applied to the fθ lens 11 including a cylindrical lens formed by combining four lenses.
4, the light is reflected by a mirror 116 provided on the optical path extending in the main scanning direction, and the film F is conveyed in the arrow Y direction (sub-scanned) by the conveying device 142. Main scanning is repeatedly performed on the scanning surface in the arrow X direction. That is, the laser beam L scans over the entire surface to be scanned on the film F.

The cylindrical lens of the fθ lens 114 transfers the incident laser beam L onto the surface of the film F to be scanned.
It converges only in the sub-scanning direction.
The distance from the θ lens 114 to the surface to be scanned of the film F is equal to the focal length of the fθ lens 114 as a whole. As described above, in the present exposure apparatus 100, the cylindrical lens 115 and the fθ lens 114 including the cylindrical lens are provided 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 deviated, the scanning position of the laser beam L on the surface to be scanned of the film F is not shifted in the sub-scanning direction, and the scanning lines are arranged at a constant pitch. Can be formed. 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, the film F
A latent image based on the image signal S is formed.
In this embodiment, the film F is irradiated with the laser beam when being conveyed by the conveying roller 142. However, the film F is wound around the inner periphery of a hollow drum, and the drum is rotated. Alternatively, the film F may be irradiated with laser light.

FIG. 2 is a longitudinal sectional view of the heat developing apparatus according to the present embodiment. In FIG. 2, the heat developing device 2
Reference numeral 00 denotes a supply unit 200A for supplying a sheet-shaped exposed film F from the side of an exposure apparatus (not shown in FIG. 2).
And a film pre-heated by the pre-heating unit 200B, and a pre-heating unit 200B that pre-heats the film F supplied from the supply unit 200A while transporting the film F along the substantially horizontal transport path 26. Substantially horizontal transport path 26
Developing unit 20 that heats and thermally develops while transporting along
0C and the film F which has been heat-developed by the heat developing section 200C.
And a cooling unit 200D that cools while transporting.

In the supply section 200A, a pair of entrance-side rollers 2 is disposed at an introduction section for receiving the film F from the exposure apparatus. The entrance roller 2 has a function of receiving the film F and sending the film F to the preheating unit 200B.

A pair of nip rollers 56 are arranged on the inlet side of the preheating unit 200B. The nip roller 56 seals the entrance of the preheating unit 200B so that unnecessary airflow does not occur along the transport path 26.
Behind the transport path 26, three transport rollers 1
4 are arranged in parallel, and four conveyance rollers 16 are arranged below the conveyance path 26 so as to sandwich the conveyance roller 14. That is, the preheating unit 200
In B, the transport rollers 14 and 16 are provided so that the nip portion sandwiching the transport path 26 is at two or more locations.

Heating members 28 and 32 are disposed further above and below the transport rollers 14 and 16 which are vertically arranged in a staggered manner with the transport path 26 interposed therebetween. Heating member 28,3
2 has a fin portion 40 formed so as to surround the transport rollers 14 and 16. By heating the transport rollers 14 and 16, the film F held and transported by the transport rollers 14 and 16 is indirectly transferred. Can be heated.

By reducing the clearance between the fins 40 and the film F conveyed along the conveyance path 26,
Radiative thermal conductivity can be improved. However, it is desired that the fins 40 do not come into contact with the film F in order to prevent uneven heating and jamming. It is preferable that the support members 20 of the transport rollers 14 and 16 have a low heat capacity and a low thermal conductivity because the heat balance is reduced and the temperature control is facilitated.

In the thermal developing section 200C, nine rotating rollers 4 are arranged at equal intervals above the transport path 26 with an inter-axis distance of L. A belt driving device 6 having a pair of pulleys 6a and a belt 6b stretched therebetween is disposed below the conveyance path 26. A heat source 7 such as a sheath heater is arranged above the rotating roller 4, and a heat source 8 such as a sheath heater is similarly arranged between the belts of the belt driving device 6.

FIG. 3 is an axial sectional view of the rotary roller 4. In FIG. 3, the rotating roller 4a has a drum-shaped core 4b made of stainless steel or aluminum, and a tube 4a made of silicon or the like fitted on the outer periphery of the core 4a. Support shafts 4c are formed at both ends of the cored bar 4b, and the support shafts 4c are rotatably supported by the housing 1 (FIG. 2) by bearings (not shown).

The thermal conductivity of the surface material of the rotating roller 4, ie, the tube 4a, is 0.2 W / (m · K) or more and 1.0
W / (m · K) or less, and its specific electrical resistance is 10 ¹⁴ Ω
m or less. Furthermore, the distance L (mm) between the centers of the adjacent rotating rollers 4 and the diameter D (mm) of the rotating rollers 4 satisfy the following expression. 50 ≦ L ≦ 200 (1) 20 ≦ D ≦ 50 (2) 30 ≦ LD ≦ 150 (3)

FIG. 4 is a cross-sectional view showing the structure of the belt 6b disposed so as to face the rotating roller 4, and shows a state in which the film F is being conveyed. The belt 6b has a nonwoven fabric 6d coated on the outer peripheral surface of a stainless steel belt-shaped support 6c. The nonwoven fabric 6d has many hairs implanted on the surface.

The thermal conductivity of the belt-like support 6c is 0.2
It is not less than W / (m · K) and not more than 10 W / (m · K), and its specific electric resistance is not more than 10 ¹⁴ Ωm.

Each of the rotating rollers 4 and the belt driving device 6 are driven synchronously by power from a power source (not shown).
As a result, the film F is supported from below the transport path 26 and transported below the rotary roller 4.

The pressure between the nip rollers 56 is 15 g / sq. Cm or more and 40 g / sq. Cm or less, and the pressure between the rotating roller 4 and the belt 6 b is 0 g / sq.
It is square cm or more and 40 g / square cm or less.

In the cooling section 200D, the transport path 26
It extends downward through the cooling chamber 44 provided with the cooling fan 54 and reaches a pair of nip rollers 50. Nip roller 50
Below, is provided a parallel linear cooling guide 60,
It extends to a pair of discharge rollers 62.

A deodorizing filter 52 is provided adjacent to the cooling section 200D. The deodorizing filter 52 includes a filter portion (not shown) of activated carbon or the like, and has a function of adsorbing an organic solvent or the like volatilized from the film F during thermal development.

Next, the mode of thermal development in the present embodiment will be described with reference to FIG. First, in the exposure apparatus (FIG. 1), the film F on which a latent image is formed enters between the entrance rollers 2 and is sent out to the preheating unit 200B by the rotating entrance rollers 2.

In the preheating section 200B, the film F enters between the rotating nip rollers 56, and is further moved along the transport path 26 while being sandwiched between the rotating transport rollers 14, 16 arranged in a staggered manner. . At this time,
Heated by the heat sources 28 and 30, the film F
00 ° C to 115 ° C, more preferably 105 ° C to 110 ° C
Heated until. At such a temperature, development does not occur on the film F.

The film F sent from the preheating unit 200B to the thermal developing unit 200C by the conveying rollers 14 and 16 is sandwiched between the rotating roller 4 and the belt driving device 6, and is conveyed while being heated. You. More specifically,
The rotating roller 4 supplies radiant heat to the upper surface of the film F when the outer peripheral surface heated from the upper heat source 7 rotates and faces the film F.

On the other hand, the belt-shaped support 6c is heated by heat from the heat source 8 arranged in the belt driving device 6,
The radiant heat is supplied to the lower surface of the film F. Due to such radiant heat, the surface of the film F has a heat development temperature of 12
Heat to 0 ° C to 125 ° C, preferably to 123 ° C.
When the film F is heated by using the radiant heat as described above, the surface of the film F can be uniformly heated as compared with the direct heating.

At this time, as shown in FIG. 4, the conveyed film F has its lower surface supported by the bristles of the nonwoven fabric 6d.
Since the side portions are also covered with the hairs of the nonwoven fabric 6d, a space insulated by the air layer held between the hairs is generated, thereby providing a heat balance between the film F and the outside. Thus, the film F can be heated as uniformly as possible.

When the film F sent from the heat developing section 200C passes through the cooling chamber 44 of the cooling section 200D, the film F is uniformly cooled by, for example, the air blown by the fan 54 so that the entire surface is kept at 60 ° C. or less. As a result, the thermal development of the film F is stopped immediately, and the operator does not feel heat even if the operator grips the film F in the next step. The cooled film F is discharged to the outside via the guide 60 and the discharge roller 62. In addition, film F
When the film F is rapidly cooled, curling or the like is likely to occur. However, in the present embodiment, since the film F is linearly supported using the guide 60, curling can be suppressed.

It should be noted that the supply section 200A and the preheating section 200
The transport speed of the film F to B, the transport speed of the film F in the preheating unit 200B and the thermal developing unit 200C, and the transport speed of the thermal developing unit 200C to the cooling unit 200D are substantially the same transport speed. Yes, 1 cm / sec or more and 3 cm / sec or less.

The air flow S1 from the cooling fan 54 in the cooling chamber 44 passes through the side (left side) of the film F conveyed along the conveying path 26 and is discharged to the outside. On the other hand, another air flow S2 from the cooling fan 54 flows along the image forming surface of the film F conveyed along the conveyance path 26, and passes through the tube 52a to remove the deodorizing filter unit 5.
2 to be inhaled. When flowing along the image forming surface, the air flow S2 takes in an organic solvent or the like released during thermal development, is sucked as it is by the deodorizing filter unit 52, adsorbs the organic solvent or the like by a filter (not shown), and cleans the air. The exhausted air is discharged from the deodorizing filter section 52.

According to the present embodiment, heat development section 200C
The surface material of the belt 6b in the belt driving device 6 is a non-woven fabric, and the heat conductivity of the tube 4a of the rotating roller 4 is 0.2 W / (m · K) or less. Can be formed, and the space other than the transport path 26 can be insulated, so that the air does not easily flow, and the temperature of the thermal developing section 200C can be controlled relatively easily. Further, the heat conduction with the surroundings can be suppressed, the temperature distribution in the transport path 26 of the heat developing section 200C can be easily made uniform, the fluctuation of the heat developing temperature due to the fluctuation of the surrounding temperature can be suppressed, and the preheating can be further reduced. In the section 200C, the pre-heating is performed while the transport rollers 14, 16 are sandwiched between two or more nips, so that the heat developability of the film F is improved. Thereafter, the heat development is performed in the heat development section 200C. Is small, it is easy to suppress the temperature unevenness in the thermal developing unit 200C, and the thermal conductivity of the surface material 4a of the rotating roller 4 is 1.0 W / (m · K).
As described above, the film F can be heated to the heat development temperature in a short time to perform the heat development for a predetermined time.

Further, in the present embodiment, the belt 6b of the belt driving device 6 has a structure in which the nonwoven fabric 6d is provided on the surface side of the belt-like support 6c.
Has a thermal conductivity of 0.2 W / (m · K) or more and 10 W / (m · K
K) The following is true. The thermal conductivity of the belt-like support 6b is 0.
Since it is 2 W / (m · K) or more, temperature unevenness in the belt-shaped support 6 b is less likely to occur, density unevenness of the thermally developed film F is suppressed, and thermal conductivity of the belt-shaped support 6 b is reduced. Is less than 0.2 w / (m · K), it is difficult for heat to escape to the surroundings, and the heat developing unit 200
The time until the temperature of C reaches a predetermined developing temperature can be shortened.

Further, in the present embodiment, the specific electric resistance of the tube 4a of the rotating roller 4 is 10 ¹⁴ Ωm or less and the specific electric resistance of the belt-like support 6c is 10 ¹⁴ Ωm or less. 6d, rotating roller 4 and film F
Even if static electricity is generated between the film 4a and the film 4a, the specific electric resistance of the tube 4a is as low as 10 ¹⁴ Ωm or less, and the specific electric resistance of the belt-shaped support 6b is as low as 10 ¹⁴ Ωm or less. Discharge to the battery.

Further, in the present embodiment, since the specific heat of the tube 4a of the rotating roller 4 is 1.5 J / (Kg) or more, the heat is deprived to the film F and the surface temperature of the rotating roller 4 decreases. It is possible to prevent the temperature of the film F, which is suddenly lowered, from lowering, so that the heat development temperature of the film F to be conveyed later is suppressed, stable heat development can be performed, and the occurrence of density unevenness can be suppressed.

Further, in this embodiment, since the variation in the surface temperature of the rotating roller 4 during thermal development is 2 ° C. or less, the variation in the temperature of the rotating roller 4 is small. Can be

Further, in the present embodiment, the distance L (mm) between the centers of the adjacent rotating rollers 4 and the distance between the rotating rollers 4
Since the diameter D (mm) of the film satisfies the following formula, 50 ≦ L ≦ 200 20 ≦ D ≦ 50 30 ≦ LD ≦ 150 The lifting of the film F from the belt 6b is suppressed, and the film F Can be conveyed, the density unevenness due to the deflection of the conveyance can be suppressed, and since there is no large space above the belt 6b, the air does not easily flow.
Can be relatively easily controlled, heat conduction with the surroundings can be suppressed, the temperature distribution in the transport path 26 of the heat developing section 200C can be easily made uniform, and thermal development due to fluctuations in the surrounding temperature can be easily achieved. Temperature fluctuation can be suppressed,
In addition, parts costs and manufacturing costs can be reduced.

Further, in the present embodiment, the pressure between the conveying rollers 14 and 16 is 15 g / square c.
m to 40 g / square cm, and the pressure between the rotating roller 4 and the belt 6b of the belt driving device 6 is 0 g / sq.
Of the film F can be suppressed while further improving the thermal developability of the film F.

Further, in the present embodiment, the supply unit 2
00A to the preheating unit 200B, the conveyance speed of the film F of the preheating unit 200B and the heat development unit 200C, and the conveyance speed of the film F from the heat development unit 200C to the cooling unit 20B.
Since the transport speed to 0D is substantially the same as the transport speed and is 1 cm / sec or more and 3 cm / sec or less, it is possible to suppress the occurrence of temperature unevenness while miniaturizing the apparatus, , The thermal development temperature can be kept constant, and density unevenness can be suppressed.

The film F contains photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent.
Since thermal development is not substantially performed at the following temperature, and thermal development is performed at a temperature equal to or higher than the minimum development temperature of 80 ° C. or higher (eg, 120 ° C.), thermal development is substantially not performed at room temperature. The saved image can be stored for a long time.

The thermal developing section 200C thermally develops the film F at a thermal developing temperature higher than the minimum developing temperature for a predetermined thermal developing time. Since the heating is performed up to the temperature, better thermal development can be performed.

FIG. 5 is a cross-sectional view of the film F shown in the example, and is a diagram schematically showing a chemical reaction in the film F during exposure. FIG. 6 is a cross-sectional view similar to FIG. 5, schematically showing a chemical reaction in the film F during heating. In the film F, a photosensitive layer mainly composed of polyvinyl butyral is formed on a support (base layer) made of PET, and a protective layer made of cellulose butyrate is further formed thereon. The photosensitive layer contains silver behenate (Beh. Ag), a reducing agent and a toning agent.

When the film F is irradiated with the laser beam L from the exposure unit 100 during 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 a temperature equal to or higher than the minimum thermal development temperature, as shown in FIG. 6, silver ions (Ag ⁺ ) are released from silver behenate, and the behenic acid releasing silver ions becomes complex with the toning agent and the complex. To form Thereafter, silver ions are diffused, and the reducing agent acts with the exposed silver halide grains as nuclei to form a silver image by a chemical reaction. As described above, 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 less,
Thermal development is performed at a temperature not lower than the minimum development temperature of not less than ° C.

The light-sensitive silver halide used in the heat-developable material is typically 0.75 to 25 with respect to the organic silver salt.
mol% can be used, preferably
It can be used in the range of 2 to 20 mol%.

The silver halide may be silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chlorobromoiodide,
Any photosensitive silver halide such as silver chlorobromide may be used. The silver halide may be in any form that is photosensitive, including, but not limited to, cubic, orthorhombic, tabular, tetrahedral, and the like.

Organic silver salts are any organic materials that contain a source of silver on reduction. Organic acids, especially long chain fatty acids (10
-30 carbon atoms, preferably 15-28 carbon atoms)
Are preferred. When the ligand is 4.0 to 10.0 overall
It is preferable that the organic or inorganic silver salt complex has a certain stability between the two. Then, about 5% of the weight of the image forming layer
It is preferably about 30%.

The organic silver salt which can be used in the heat developing material is a silver salt which is relatively stable to light, and which contains an exposed photocatalyst (for example, photographic silver halide) and a reducing agent. Is a silver salt that forms a silver image when heated to a temperature of 80 ° C. or higher.

Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. They include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate, silver stearate and the like. Silver salts with halogen atoms or hydroxyl in aliphatic carboxylic acids can also be used effectively. Silver salts of compounds having a mercapto or thione group and derivatives thereof can also be used. Further, a silver salt of a compound having an imino group can be used.

The reducing agent for the organic silver salt may be any material that can reduce silver ions to metallic silver, and is preferably an organic material. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful. However, phenol reducing agents are preferred. The reducing agent is used in the image forming layer.
It should be present at 10% by weight. In a multi-layer configuration,
If the reducing agent is added to a phase other than the emulsion layer, a slightly higher proportion, about 2 to 15% by weight, is more desirable.

[0064]

Hereinafter, the film F will be described. Silver halide-silver behenate dry soap is disclosed in U.S. Pat.
Prepared by the method described in No. 049. The silver halide had 9 mole% of the total silver, while silver behenate had 91 mole% of the total silver. The silver halide was a 0.055 μm silver bromoiodide emulsion having 2% iodide.

The heat-developed emulsion was homogenized with 455 g of the above-mentioned silver halide-silver behenate dry soap, 27 g of toluene, 1918 g of 2-butanone, and polyvinyl butyral (B-79 manufactured by Monsanto). The homogenized heat-developed emulsion (698 g) and 60 g of 2-butanone were cooled to 12.8 ° C. while stirring. Pyridinium hydrobromide perbromide (0.92 g) was added and stirred for 2 hours.

3.25 ml of a calcium bromide solution (CaBr (1 g) and 10 ml of methanol) were added, followed by stirring for 30 minutes. Further, polyvinyl butyral (158 g; B-79 manufactured by Monsanto) was added, and 20
Stirred for minutes. The temperature was raised to 21.1 ° C. and the following was added with stirring over 15 minutes. 3.42 g of 2- (tribromomethylsulfone) quinoline, 28.1 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 5-methylmercaptobenzimidazole Solution containing 0.545 g 41.1 g, 2- (4-chlorobenzoyl) benzoic acid 6.12 g S-1 (sensitizing dye) 0.104 g methanol 34.3 g Isocyanate (Desmoder N3300, manufactured by Mobay) 2.14 g Tetrachlorophthalic anhydride 0.97 g Phthalazine 2.88 g The dye S-1 has the following structure.

Embedded image

An active protective topcoat solution was prepared using the following components: 2-butanone 80.0 g methanol 10.7 g cellulose acetate butyrate (CAB-171-155, manufactured by Eastman Chemicals) 8.0 g 4-methylphthalate Acid 0.52 g MRA-1, Mottle reducing agent, N-ethyl perfluorooctanesulfonylamide ethyl methacrylate / hydroxyethyl methacrylate / acrylic acid weight ratio 70:20:10 Tertiary polymer 0.80 g

The heat-developable emulsion and the tobcoat were simultaneously coated on a 0.18 mm blue polyester film base. The knife coater was set up with two bars or knives coating simultaneously at a distance of 15.2 cm. The silver trip layer and the top coat were multi-layer coated by pouring the silver emulsion on the film prior to the rear knife and the top coat on the film prior to the front bar.

The film was then drawn forward so that both layers were coated simultaneously. This was obtained by performing the multilayer coating method once. The coated polyester base was dried at 79.4 ° C. for 4 minutes. As the knife, as dry coating weight per 1 m ² for the silver layer is 23g, then dry coating weight per 1 m ² is adjusted so as to be 2.4g for the top coat Was.

[0070]

According to the present invention, since the photosensitive heat developing material can be uniformly heated, it is particularly suitable for a heat developing apparatus for making a newspaper plate.

[Brief description of the drawings]

FIG. 1 is a view showing a schematic configuration of an exposure apparatus 100.

FIG. 2 is a longitudinal sectional view of the heat developing device according to the exemplary embodiment;

FIG. 3 is an axial sectional view of the rotating roller 4;

FIG. 4 shows a belt 6b arranged to face the rotating roller 4.
It is sectional drawing which shows a structure of.

FIG. 5 is a cross-sectional view of the film F, schematically showing a chemical reaction in the film F during exposure.

FIG. 6 is a sectional view similar to FIG. 8, schematically showing a chemical reaction in the film F during heating.

DESCRIPTION OF SYMBOLS 100 Exposure device 200 Thermal developing device 200A Supply unit 200B Preheating unit 200C Thermal developing unit 200D Cooling unit 4 Rotary roller 6 Belt drive device 14, 16 Transport roller F Film

Claims (12)

[Claims] 1. A connecting section for supplying a sheet-shaped exposed photosensitive thermal developing material, and preheating the thermal developing material supplied from the supplying section while transporting the thermal developing material along a substantially horizontal transport path. A pre-heating unit, a heat development unit that heats and develops the heat development material preheated by the pre-heating unit along a substantially horizontal conveyance path, and thermally develops the heat development material. The heat development material, having a cooling unit that cools while transporting, In the heat development unit, heat development is performed at a predetermined heat development temperature equal to or higher than the lowest heat development temperature at which the heat development material is thermally developed, In the preliminary heating unit, a conveyance roller is provided so that a nip portion sandwiching the conveyance path is provided at two or more locations. In the heat development unit, the heat development material is supported from below the conveyance path. Belt that conveys while moving, facing the conveyor belt A heat developing device having at least two rotating rollers provided so as to sandwich the conveying path, wherein the surface material of the conveying belt is a non-woven fabric; 2W / (m
(K) or more and 1.0 W / (m · K) or less. 2. The conveyor belt has a structure in which a nonwoven fabric is provided on the surface side of a belt-like support, and the belt-like support has a thermal conductivity of 0.2 W / (m · K).
The thermal developing device according to claim 1, wherein the thermal development device is not less than 10 W / (m · K). 3. The specific resistance of the surface material of the rotating roller is 10 ¹⁴ Ωm or less, and the specific resistance of the belt-shaped support is 10 ¹⁴ Ωm or less. 3. The thermal developing device according to claim 1. 4. The specific heat of the surface material of the rotating roller is 1.
2. The method according to claim 1, wherein the amount is 5 J / (Kg) or more.
4. The thermal developing apparatus according to any one of claims 1 to 3, wherein 5. The method according to claim 1, wherein a variation in the surface temperature of the rotating roller during thermal development is 2 ° C. or less.
5. The thermal developing device according to any one of 4. 6. A distance L between centers of adjacent rotating rollers.
The heat developing device according to claim 1, wherein (mm) and a diameter D (mm) of the rotating roller satisfy the following expression. 50 ≦ L ≦ 200 20 ≦ D ≦ 50 30 ≦ LD ≦ 150 7. A supply section for supplying a sheet-form exposed photosensitive thermal development material, and preheating for preheating the thermal development material supplied from the supply section along a substantially horizontal transportation path. Part, a heat developing part that heats and develops the heat developing material preheated by the preheating part while transporting the heat developing material along a substantially horizontal conveying path; A cooling unit that cools the heat development material while transporting the heat development material, wherein the heat development unit performs heat development at a predetermined heat development temperature equal to or higher than a minimum heat development temperature at which the heat development material is thermally developed; In the heating unit, a conveyance roller is provided so that the nip portion sandwiching the conveyance path is at two or more places. In the heat development unit, the heat development unit conveys the heat development material from below the conveyance path. Transport belt, and facing the transport belt In a heat developing apparatus having two or more rotating rollers provided so as to sandwich the conveying path, a distance L (mm) between centers of adjacent rotating rollers and a diameter D (mm) of the rotating rollers are equal to each other. A heat developing device characterized by satisfying the following expression. 50 ≦ L ≦ 200 20 ≦ D ≦ 50 30 ≦ LD ≦ 150 8. The method according to claim 8, wherein the pressure between the transport rollers is 15
g / square cm or more and 40 g / square cm or less, and the pressure between the rotating roller and the transport belt is 0 g / square cm.
The heat developing device according to any one of claims 1 to 7, wherein the heat developing device has a square cm or more and 40 g / square cm or less. 9. A supply section for supplying a sheet-shaped exposed photosensitive thermal development material, and preheating while removing the thermal development material supplied from the supply section along a substantially horizontal transport path. A pre-heating unit that heats the heat-developable material preheated by the pre-heating unit along a substantially horizontal conveyance path to heat and thermally develop the heat-developable material; A cooling unit that cools the developed heat-developable material while transporting the heat-developable material. In the preliminary heating unit, a conveyance roller is provided so that the nip portion sandwiching the conveyance path is at two or more places. In the heat development unit, the heat development material is supported from below the conveyance path. Transport belt that transports A developing device having two or more rotating rollers provided so as to sandwich the transport path in the opposite direction, wherein the pressure between the rollers of the transport roller pair is 15 g / cm 2
40 g / cm 2 or less, and the pressure between the rotating roller and the conveyor belt is 0 g / cm 2.
A heat developing device having a square cm or more and 40 g / square cm or less. 10. A transport speed of the thermal developing material from the supply unit to the preheating unit, a transport speed of the thermal developing material in the preheating unit and the thermal developing unit, and a cooling speed from the thermal developing unit. The thermal developing device according to claim 1, wherein the transport speed to the unit is substantially the same, and is 1 cm / sec or more and 3 cm / sec or less. 11. The heat-developable material contains photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent.
In any one of claims 1 to 10, the composition is not substantially thermally developed at a temperature of 0 ° C. or less, and is thermally developed at a temperature of 80 ° C. or more and a minimum development temperature or more. The thermal developing device according to any one of the preceding claims. 12. The heat developing section heat-develops the heat-developable material at a heat development temperature not lower than the minimum development temperature for a predetermined heat development time, and the preheating section includes 12. The heat developing apparatus according to claim 11, wherein the apparatus is heated to a temperature equal to or lower than a heat developing temperature.