JPH05107724A - Photosensitive material drying device - Google Patents

Abstract

PURPOSE:To obtain the photosensitive material drying device which dries a photosensitive material without spoiling its finish. CONSTITUTION:A film 20 is held and conveyed by a conveyor roller couple 80 in a drying chamber 78. A hot air generation part 100 is arranged below the drying chamber and linked to a chamber 88 arranged along a conveyance path through a duct 86. In the duct 86, an internal duct 108 which is sectioned by a couple of side plates 106 is provided and communicated to the inside of a chamber which is partitioned by a couple of side plates 110. An auxiliary heater 112 is arranged in the internal duct and a hot air generated at the hot blast generation part is heated and supplied to the parts of the chamber partitioned by the side plates 110. The film is heated with the hot air at a front-stage part 94 A with the hot air from the hot air generation part, and heated and dried at an intermediate-stage part 94 with the hot air made high in temperature by the auxiliary heater 112. Further, the hot air from the hot air generation part is blown at a rear-stage part and the film is discharged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive material drying apparatus for drying a photosensitive material processed by a processing liquid.

[0002]

2. Description of the Related Art As the electronics field advances, rapid processing is required also in the silver halide photographic field. In particular, the demand for rapid processing for photosensitive materials such as graphic arts sensitive materials, scanner sensitive materials, and X-ray sensitive materials is increasing. The rapid processing referred to here means, for example, that the leading edge of the photosensitive material is inserted into a photosensitive material processing device such as an automatic developing machine, and then passes through a processing section including a developing tank, a fixing tank, a washing tank, and a drying section, It takes 20 minutes for the leading edge of the photosensitive material to be discharged from the drying section.
It means a process that is from seconds to 60 seconds. If the conveyance speed of the photosensitive material is simply increased in order to shorten the processing time of the processing section and the drying section, various problems such as poor fixing and poor drying occur.

With respect to improper fixing, it is known to increase the concentration of thiosulfate in the fixing solution in order to increase the fixing speed. It is also known and widely used to incorporate a hardening agent such as a water-soluble aluminum salt in the fixing solution in order to harden the film surface of the light-sensitive material and improve the drying property. However, when the photosensitive material is treated with a fixing agent containing a hardening agent such as a water-soluble aluminum salt, the fixing speed is delayed due to the hardening effect, so that the hardening agent is substantially added to the fixing solution to increase the fixing speed. If it is not included, there is a problem that the swelling rate of the emulsion coated on the light-sensitive material becomes large and the drying property deteriorates. As described above, the fixing speed is improved by reducing the water-soluble aluminum salt which is a hardening agent in the fixing solution, but it has a disadvantage in shortening the drying time which is important in the rapid processing, and therefore, the conventional method has been substantially used. Few attempts have been made to process light-sensitive materials with fixers that do not contain hardeners.

By the way, the exposed light-sensitive material is subjected to a processing liquid treatment such as development, fixing and washing with a light-sensitive material processing device, and then dried in a drying section. In this drying section, while the photosensitive material is being conveyed by a plurality of rollers, warm air heated by the heating means is blown onto the photosensitive material to dry it.

In the drying section for drying the light-sensitive material, in order to dry the light-sensitive material efficiently and in a short time, the drying process is divided into a front stage and a rear stage, and high-temperature hot air is blown to the light-sensitive material in the front stage. In general, after drying, a warm air having a temperature lower than that in the former stage is blown to dry the photosensitive material in the latter stage so that the photosensitive material becomes a predetermined dry state.

[0006]

However, when the photosensitive material is rapidly sprayed with high temperature hot air to dry it when the photosensitive material contains a large amount of water, a high energy is required for the drying. The device becomes large. In addition, since the moisture content of the photosensitive material is non-uniform in the initial stage of drying, there is a problem that unevenness in the finished product is likely to occur when it is rapidly exposed to a high temperature.

The present invention has been made in consideration of the above facts, and an object of the present invention is to provide a light-sensitive material drying apparatus capable of efficiently drying without damaging the finish of the light-sensitive material.

[0008]

A light-sensitive material drying apparatus of the present invention for achieving the above object is a light-sensitive material drying apparatus for drying a light-sensitive material processed by a processing liquid while conveying the light-sensitive material. Warm air generating means for generating warm air to be supplied to dry the photosensitive material into a drying chamber for drying, and heating the warm air supplied from the warm air generating means to an intermediate portion in the conveying direction in the drying chamber. Heating means for making the temperature of the warm air in the middle portion higher than the temperature of the surrounding warm air.

[0009]

The photosensitive material drying apparatus according to the present invention dries the photosensitive material by the hot air supplied into the drying chamber. Further, the warm air supplied to the intermediate portion in the transport direction has a higher temperature than other portions by the heating means.

As a result, the photosensitive material conveyed in the drying chamber is supplied with warm air from the warm air generating section in the former stage, and is further heated with the heating means in the middle stage. Further, in the latter stage, warm air is supplied from the warm air generating unit and dried.

The heating means is adapted to further heat the warm air generated in the warm air generating section, so that the warm air having a relatively high temperature can be easily and efficiently obtained.

That is, after the light-sensitive material is preliminarily heated to make the water content substantially uniform, it is heated and dried at a high temperature in the middle step, and the surface temperature of the light-sensitive material is lowered in the latter step and the dry state is gradually optimized. You can approach the state. As a result, the photosensitive material can be dried in a short time without causing defective finish such as unevenness of drying of the photosensitive material.

In the present invention, the photosensitive material is not heated at a high temperature when the moisture content of the photosensitive material is non-uniform. Therefore, even if the emulsion layer is not hardened and the photosensitive material contains a large amount of water in a non-uniform state, the water content is made substantially uniform by preheating and then dried by heating at a high temperature. Since the surface temperature of the material is lowered to bring the dried state close to the optimum state, it is possible to dry in a shorter time than the conventional drying method without causing unevenness in the finish. That is, it may be a light-sensitive material processed with a fixing solution containing substantially no hardener, and of course, a light-sensitive material processed with a fixer containing a hardener can be dried.

Next, the fixing agent and hardening agent of the fixing solution that can be used in the photosensitive material processing apparatus equipped with the drying apparatus of the present invention will be described.

For example, as the fixing agent used in the present invention, in addition to thiosulfates and thiocyanates, organic sulfur compounds known to be effective as a fixing agent can be used.

Water-soluble aluminum salts can be used as a hardening agent in the fixing solution. Examples of water-soluble aluminum salts include aluminum sulfate, ammonium aluminum sulfate, aluminum potassium sulfate, and aluminum chloride.

Here, the above-mentioned treatment with a fixing solution containing substantially no hardener means that the hardening of the emulsion layer of the light-sensitive material immersed in the fixing solution is not substantially caused. However, more specifically, it means that the amount of the water-soluble aluminum salt added to the fixing solution is preferably 0 to 0.01 mol / liter, more preferably 0 to 0.005 mol / liter. As a result, the processing time of the fixing process can be shortened, and the efficiency of washing with water can be improved, so that the residual color of the photosensitive material after processing can be reduced. The pH of the fixing solution is preferably 5.3 or more, and further 5.5
~ 7.0 is more preferable.

The amount of sulfite in the fixing solution is preferably 0.05 to 1.0 mol / liter, more preferably 0.07 to 0.8 mol / liter.

The fixing agent which can be used in the present invention can contain various acids, salts, chelating agents, surfactants, wetting agents, fixing accelerators and other additives in addition to the above compounds.

Examples of the acid include inorganic acids such as sulfuric acid, hydrochloric acid, nitric acid and boric acid, formic acid, propionic acid, oxalic acid,
Examples thereof include organic acids such as phthalic acid.

Examples of the salt include salts of these acids such as lithium, potassium, sodium and ammonium.

Examples of the chelating agent include anionic surfactants such as sulfates and sulfone compounds, nonionic surfactants such as polyethylene glycol and ester compounds, and JP-A-57-6840 (name of invention, fixing for photography). Liquid) and the amphoteric surfactant described in the above.

Examples of the wetting agent include alkanolamine and alkylene glycol.

As the fixing accelerator, for example, Japanese Patent Publication No. 45-
35754, JP-A-58-122535, 58-
No. 122536, thiourea derivatives, alcohols having a triple bond in the molecule, US Pat.
Examples thereof include thioethers described in 6,459.

Among the above additives, acids and salts such as boric acid and aminopolycarboxylic acids are preferred because they have the effect of promoting the object of the present invention. More preferably boric acid (salt)
It is a fixing agent containing. The preferable addition amount of boric acid (salt) is 0.5 to 20 g / liter. More preferably, the amount is sufficient to be 4 to 5 g / liter.

The present invention can be applied to various photosensitive materials such as printing, X-ray, general negative, general reversal, general positive, and direct positive.

[0027]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a schematic block diagram of a photosensitive material processing apparatus 10 according to this embodiment. Photosensitive material processing apparatus 1
0 has a function of developing the film 20 as a light-sensitive material, a function of fixing, a function of washing with water, and a function of drying.

The photosensitive material processing apparatus 10 includes a lid 1 which is a part of an openable / closable main body cover which shields light from the outside.
A housing 18 having 2, 14, 16 provided on the upper portion is provided. An insertion table 22 for inserting the film 20 is provided on the upper front side of the housing 18, and a film stocker 24 for storing the processed film is provided on the rear side.

An insertion opening 26 for inserting the film 20 is formed near the insertion table 22 of the housing 18, and a detector 28 for detecting passage of the film 20 is attached near the insertion opening 26. ing.

The detector 28 has a structure in which a plurality of light emitting elements and light receiving elements are arranged in the film width direction in the vicinity of the film insertion opening 26 and are arranged in the width direction of the film. By being shielded from light, each light receiving element is turned on and off according to the width and length of the inserted film 20. The detector 28 may be a type of detector that is turned on and off when the light receiving element receives the light of the light emitting element reflected by the film 20.

Inside the housing 18, a box-shaped processing tank main body 30 having an upper opening is arranged. The inside of the processing tank body 30 is partitioned by a partition wall 32, and a developing tank 34, a fixing tank 36, and a water washing tank 38 are sequentially formed.
The developing tank 34 is deeper than the fixing tank 36 and the water washing tank 38. The depth of the fixing tank 36 is the washing tank 38.
It is said to be the same depth as the depth of.

A transfer rack 40 is inserted and arranged in the developing tank 34, and a transfer rack 42 is provided in the fixing tank 36 and the washing tank 38.
Are arranged.

The transport rack 40 has a pair of side plates (only one side plate is shown in FIG. 1 and the other side plate is omitted) 44, and the side plates 44 are arranged in a staggered manner and are rotatable. A plurality of transport rollers 46 supported by the are provided. Further, a guide 48 for reversing the film 20 is arranged below the side plate 44. Transport roller 4
6 is rotated by the driving force of a driving means (not shown) being transmitted to convey the film 20.

The transport rack 40 lowers the film 20 inserted into the developing tank 34 to the bottom, then reverses it, and then ascends to the upper portion of the developing tank 34 to transport the film 20 to the developing tank 3.
Send out from within 4. As a result, the film 20 is developed with the developer stored in the developing tank 34.

The transport rack 42 has a pair of side plates (only one side plate is shown in FIG. 1, and the other side plate is not shown).
0, two rollers 52 arranged vertically between these side plates 50, a large-diameter roller 54 arranged below them, and a small-diameter roller arranged in contact with these rollers 52, 54. Rollers 56 are provided. Further, a guide 58 for reversing the film 20 is arranged below the side plate 50. The rollers 52, 54, and 56 receive the driving force of a driving unit (not shown) to nip and convey the film 20.

The transport rack 42 lowers and conveys the film 20 fed into the fixing bath 36 or the washing bath 38 toward the bottom, then reverses and raises the film 20 and sends it out from the fixing bath 36 or the washing bath 38. As a result, the film 20 conveyed in the fixing tank 34 is fixed by the fixing liquid stored in the fixing tank 36. The film 20 transported in the washing tank 36 is washed with the washing water stored in the washing tank 38.

In the developing tank 36, a pair of conveying rollers 60 is arranged on the side of the insertion port 26. This conveying roller pair 60
The film 20 inserted through the insertion port 26 is inserted into the space, and is sent out into the developing tank 34.

Further, an upper reversing guide 62 is arranged between the developing tank 34 and the fixing tank 36 for reversing the film 20 fed from the developing tank 34 downward and guiding it toward the fixing tank 36. Has been done.

Further, between the fixing tank 36 and the washing tank 38, the crossover rack 64 for reversing the film 20 sent from the inside of the fixing tank 36 toward the inside of the washing tank 38 and inserting the film for re-washing. Are arranged.

A squeeze section 66 is provided on the downstream side of the washing tank 38 in the transport direction of the film 20, and a drying section 68 is further disposed on the downstream side.

A squeeze rack 70 is arranged in the squeeze portion 66. The squeeze rack 70 includes a pair of side plates 72 (only one side plate is shown in FIG. 1 and the other side plate is omitted), and a conveyance device arranged between the side plates 72 and rotatably supported. Roller pairs 74 and 76 are provided. These conveying roller pairs 74 and 76 are rotated by the driving force of a driving unit (not shown) being transmitted, and the washing tank 38 is washed.
The film 20 sent from the inside is nipped and conveyed toward the drying section 68. As a result, the washing water adhering to the surface of the film 20 is squeezed out.

The squeeze rack 70 has a pair of conveying rollers 7.
A substantially L-shaped cover 92 is provided so as to cover the Nos. 4 and 76. The cover 92 shuts off the washing tank 38 and the drying section 68, and prevents the warm air of the drying section 68 from flowing into the upper portions of the washing tank 38, the fixing tank 36 and the developing tank 34.

The drying section 68 is provided with a box-shaped drying chamber 78. Chambers 88 are respectively arranged above and below the drying chamber 78, and a plurality of conveying roller pairs 80 are horizontally arranged in a portion sandwiched between these chambers 88 to form a conveying path for the film 20. Has been formed. Also,
A film insertion port 78 is provided on the squeeze portion 66 side of the drying chamber 78.
A is provided, and a transport roller pair 90 and a film outlet 78B are provided on the film stocker 24 side.

The driving force of a driving means (not shown) is transmitted to the plurality of conveying roller pairs 80 and 90 to rotate, and conveys the film 20 inserted through the film insertion port 78A, which has been developed, fixed and washed. And is discharged from the film outlet 78B.

Further, in the chamber 88, a plurality of pairs of guides 82 projecting toward the conveying path of the film 20 are arranged between the conveying roller pairs 80, and the conveying roller pairs 8 on the upstream side are arranged.
The film 20 fed from 0 is guided between the pair of transport rollers 80 on the downstream side. Further, slits 84 that communicate the transport path of the film 20 and the inside of the chamber 88 are provided on the upstream side and the downstream side of each guide 82.

Each chamber 88 has one end of a duct 86 communicating with one end of the film 20 in the width direction. The other end of the duct 86 is supplied with warm air generated by a warm air generating unit 100 described later. Therefore, the duct 86
The warm air supplied from the chamber 88 to the chamber 88 passes through the chamber 88 and passes through the slit 84 and the film 20 in the drying chamber 78.
Is ejected toward the transport path. As a result, the film 20 transported by the transport roller pair 80 is dried.

As shown in FIGS. 2 to 4, the duct 8
6 is a duct main body 86A communicating with each chamber 88,
An opening on the side opposite to the chamber 88 is connected to the warm air generating section 100 by a connecting section 86C. The warm air generating unit 100 is arranged below the drying chamber 78, and the air sucked by the fan 102 from an air intake (not shown) is heated by the main heater 104 to generate warm air. ..

As shown in FIGS. 2 and 4, the duct 86 has a chamber 88 from the end on the warm air generating portion 100 side.
The opening area is gradually widened toward the side, and the warm air is supplied to the chamber 88 from the upstream end of the transport path of the film 20 to the downstream end thereof at a substantially uniform pressure. Also, as shown in FIGS. 2 and 3, the chamber 8
8, the opening area is gradually reduced from the end on the duct 86 side to the opposite side along the width direction of the transport path, and the wind velocity of the warm air discharged from the slit 84 is along the width direction of the film 20. It is almost uniform.

As shown in FIGS. 2 and 4, the duct 8
An internal duct 108 is formed inside 6 by being partitioned by a pair of partition walls 106 arranged in a substantially central portion along the flow direction of the warm air from the warm air generating unit 100. Further, the inside of the chamber 88 is partitioned by a pair of partition walls 110 at the central portion along the transport path, and communicates with the internal duct 108. An end of the internal duct 108 opposite to the chamber 88 communicates with the warm air generator 100.

As shown in FIGS. 2 to 4, an auxiliary heater 112 is arranged in the internal duct 108, and a part of the warm air from the warm air generating section 100 is contained in the internal duct 108.
And is heated by the auxiliary heater 112 and is supplied to the vicinity of the conveyance roller pair 80 located in the middle of the conveyance path. Therefore, the warm air supplied to the drying chamber 78 is supplied to the front stage portion 94A and the rear stage portion 94C of the transport path by the warm air generated in the warm air generating portion 100, and is fed to the middle stage portion 94B of the transport path. The hot air generated by the generation unit 100 and heated by the auxiliary heater 112 is supplied, and the temperature of the hot air is divided into two stages along the transport direction.

A temperature sensor 114 is attached to the duct 86 in the vicinity of the warm air generating section 100, and detects the temperature θ _S of the warm air generated by the warm air generating section 100. In addition, the auxiliary heater 1 for the internal duct 108
A temperature sensor 116 is attached above 12 to detect the temperature θ _H of the hot air supplied from the hot air generating unit 100 and further heated by the auxiliary heater 112.

The temperature sensors 114 and 116 are connected to a control device (not shown), which controls the fan 10.
2. The operation of the main heater 104 and the auxiliary heater 112 is controlled. In addition, a temperature / humidity sensor or humidity sensor (not shown) that detects the temperature / humidity or humidity outside the photosensitive material processing apparatus 10 is connected to the control device, and the temperature / humidity sensor outside the apparatus, that is, under the working environment, It is designed to detect humidity. In addition, in order to make the water content of the finished film 20 the water content at the time of the exposure, the controller 80 controls the temperature θ of the warm air so that the temperature and humidity in the working environment or a dry state corresponding to the humidity are set. _S and θ _H are obtained in advance from experimental results and stored.

Next, the operation of this embodiment will be described. The film 20 sent into the inside of the photosensitive material processing apparatus 10 from the insertion port 26 is conveyed to the developing tank 34 by the conveying roller pair 60.
After being conveyed inside, the conveying rack 40 descends and then ascends and is discharged from the developing tank 34. As a result, it is immersed in the developing solution in the developing tank 34 for development processing.

The film 2 sent out from the developing tank 34
0 is inverted downward by the upper inversion guide 66 and sent into the fixing tank 36.

The film 20 sent into the fixing tank 36.
After being transported downward by the transport rack 42, it is transported upward and is sent out from the fixing tank 36. As a result, the fixing process is performed by immersing in the fixing solution in the fixing tank 36.

The film 20 sent out from the fixing tank 36
Is inverted downward by the crossover rack 64 and sent into the water washing tank 46. The film 20 sent into the water washing tank 38 is conveyed downward by the conveying rack 42, then inverted and raised to be conveyed to the squeeze unit 66.

Film 20 conveyed to squeeze section 66
The attached water is squeezed out in the washing tank 38, and the drying unit 6
8 is conveyed horizontally in the drying chamber 78.

Warm air is supplied to the drying chamber 78, and while being horizontally conveyed by the pair of conveying rollers 80, warm air is blown from the upper and lower warm air outlets 84 to the front and back surfaces of the film 20 to be dried. ..

The film 20 dried in the drying section 68 becomes a processed film and is accumulated in the film stocker 24.

In the drying section 68, the upstream section of the drying chamber 78
And a fan 102 and a fan in the warm air generating unit 100.
Temperature θ supplied by the in-heater 104_SIn the warm air
Therefore, the dry film 20 is dried, and in the middle part
Is further increased by the warm air supplied by the warm air generation unit 100.
By the auxiliary heater 112 in the internal duct 108, the temperature θ
_HThe film 20 is dried by this warm air.
ing.

Therefore, the film 20 inserted into the drying chamber 78 is first preheated by the warm air of the temperature θ _{S in} the front part 94A of the drying chamber 78, and the hot air (temperature θ _H ) of the high temperature in the middle part 94B. Is heated by the hot air of the temperature θ _{S in} the rear stage portion 94C to be dried.

In FIGS. 5A and 5B, the drying chamber 7 is shown.
The change in the dry state of the film 20 within 8 is shown. The hot air temperatures θ _S and θ _H are controlled by a controller (not shown).

In the front part 94A of the drying chamber 78, the temperature θ _S
The film 20 is preliminarily heated by the hot air.
The film 20 inserted in the drying chamber 78 contains a large amount of water and the water content is not uniform. If the film 20 is rapidly dried in this state, uneven drying may occur, but by preheating, the moisture content of the film 20 can be made substantially uniform.

In the middle section 94B of the drying chamber 78, the film 20 is dried by the warm air heated to the temperature θ _H by the auxiliary heater 112. Although the surface temperature of the film 20 is higher than that of the front portion 94A and the water content is drastically reduced, since the water content is substantially uniform, the film can be dried in a short time without causing unevenness in drying. In the rear part 94C of the drying chamber 78, the temperature of the warm air is lowered to θ _S , and since it is in the rate-decreasing drying region, the film 2
The decrease of the water content of 0 becomes gradual. Also, the film 20
Surface temperature also drops.

In the drying chamber 78, the film 20 containing a large amount of water is not exposed to high temperature hot air from the beginning. Further, the film 20 can be set to a predetermined amount without being exposed to high temperature hot air in a state where the amount of water is reduced. As a result, the dimensions of the dried film 20 can be made substantially equal to the dimensions at the time of exposure.

Further, after the film 20 is gradually heated in the front part 94A, it is heated in the middle part 94B by hot air of high temperature θ _H. Therefore, even the film 20 in which the emulsion layer is not substantially hardened can be dried in a short time. That is, the photosensitive material drying device 1
For 0, it is possible to use a fixing solution containing substantially no hardener.

In this case, in the front stage portion 94A to which the warm air of the temperature θ _S is supplied, the film 20 formed by the pair of transport rollers 80 is used.
It is also possible to squeeze the water on the surface of the film 20 by increasing the nip force of the film and applying a roller having a hygroscopic property. Also. The nip force of the transport roller pair 80 may be weakened corresponding to the non-hardening treatment of the film 20 for the transport roller pair 80 of the middle stage portion 94B which is dried by the hot air of the high temperature θ _H. Further, the conveyance roller pair 80 of the rear stage portion 94C which is dried by the warm air of the temperature θ _S
May have a weak nip force enough to convey the film 20.

It is supplied to the middle section 94B of the drying chamber 78.
High temperature θ_HThe warm air of the
Generated temperature θ_SIt is designed to heat the warm air of
Therefore, the temperature of warm air can be raised efficiently by supplementary heating.
Can be high temperature θ _HGet warm air with a small device
You can

Further, the processing section provided as a pre-process of the drying section to which the present invention is applied is not limited to the processing of development, fixing and washing, but may be subjected to processing such as color development, bleaching, stabilization and rinsing. It may be.

[0071]

As described above, in the photosensitive material drying apparatus according to the present invention, the hot air generated by the warm air generating means is further efficiently heated by the heating means to raise the drying temperature. In addition, the photosensitive material is preliminarily heated in the initial stage of drying when the water content is not uniform, and is heated at a high temperature when the water content is substantially uniform, and the drying temperature is lowered to a predetermined value in the drying end step. A dry state can be obtained. Therefore, an excellent effect of drying the photosensitive material in a short time can be obtained without impairing the finish of the photosensitive material.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a photosensitive material processing apparatus according to the present embodiment.

FIG. 2 is a schematic exploded perspective view showing a drying unit to which the present invention is applied.

3 is a cross-sectional view of a main part taken along line 3-3 of FIG.

FIG. 4 is a cross-sectional view of essential parts taken along line 4-4 of FIG.

5A is a graph showing a change in surface temperature of the film with respect to a drying time, and FIG. 5B is a graph showing a change in water content of the film with respect to the drying time.

[Explanation of symbols]

10 Photosensitive Material Processing Device 20 Film (Photosensitive Material) 68 Drying Part 78 Drying Room 80 Conveying Roller Pair 86 Duct 88 Chamber 100 Hot Air Generating Part 104 Main Heater 108 Inner Duct 112 Auxiliary Heater θ _S , θ _H Temperature

Claims (1)

[Claims] 1. A photosensitive material drying device for drying a photosensitive material processed by a processing liquid while conveying the photosensitive material, wherein warm air is supplied to a drying chamber for drying the photosensitive material to dry the photosensitive material. The warm air generating means for heating and the warm air supplied from the warm air generating means at an intermediate portion in the conveyance direction in the drying chamber to make the temperature of the warm air in the intermediate portion higher than the temperature of the ambient warm air. And a heating unit.