JPH02277055A - Drying device for sheet material - Google Patents

Abstract

PURPOSE:To increase the energy efficiency of drying by utilizing radiation rays and to speed up response to temperature control by emitting infrared rays to a sheet material by using an infrared-ray emitting means and a reflecting means. CONSTITUTION:A photosensitive material 28 after development processing is conveyed into the drying device 10 where mirror boxes 30 are arranged, and dried with infrared rays from heaters 36 which are coated with infrared-ray emitting paint in the boxes 30. The boxes 30 are formed cylindrically of stainless steel plates and their outer peripheries and upper parts are covered with heat insulating materials 32 and 34. Further, the internal wall surfaces of the boxes 30 are reflecting surfaces and reflecting plates 31 are fitted above the heaters 36 through insulating materials to emit infrared rays to the surface of the photosensitive material 28 uniformly.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sheet material drying apparatus suitable for drying sheet materials, particularly sheet materials such as photosensitive materials after development processing.

[Prior Art] When drying a sheet material, such as a photosensitive material immediately after development, conventionally, the photosensitive material is transported into a drying chamber, and warm air is sent into the drying chamber to lower the temperature inside the drying chamber. It is dried by raising the temperature and evaporating the moisture contained in the photosensitive material.

The warm air sent into the drying chamber is obtained by sending air to a heater using a fan or the like and raising the temperature of the air by this heater. Further, the temperature of the hot air sent in this way is adjusted by turning the heater on and off.

[Problems to be Solved by the Invention] However, in conventional drying using hot air, a large amount of heat escapes to the outside together with the air, resulting in a large energy loss. Further, since it is necessary to raise the temperature of the air as well as the photosensitive material to be dried, a large amount of heat is required, and even more heat is required when the outside air is low temperature. Further, if the temperature of the air rises too much, it is not possible to lower the temperature immediately, so it is difficult to maintain a predetermined temperature constant, and the response speed of temperature adjustment is slow. Since the temperature control response is slow as described above, there is a problem in that when the temperature of the air rises too much, the photosensitive material becomes too dry, resulting in so-called overdrying.

In consideration of the above facts, the present invention aims to provide a sheet material drying device that utilizes radiant heat, has good energy efficiency, and can quickly respond to temperature adjustment.

[Means for Solving the Problems] The sheet material drying apparatus according to the present invention includes a conveying means for conveying the sheet material, an infrared radiation emitting means for emitting infrared rays,
The apparatus further includes a reflecting means for reflecting the infrared rays emitted by the infrared ray emitting means toward the surface of the sheet material being conveyed.

[Operations] According to the present invention having the above configuration, infrared rays are radiated to the conveyed sheet material by the infrared ray radiating means. in this case,
The infrared rays are reflected toward the surface of the sheet material by the reflecting means so that the infrared rays are uniformly radiated onto the surface of the sheet material.

The moisture contained in the sheet material is evaporated by the infrared rays, that is, the radiant heat emitted to the sheet material, and the sheet material is dried.

Furthermore, since radiant heat is used to prevent the temperature of the air from rising, the so-called rising speed of raising the temperature of the sheet material to a temperature at which it can be dried with good responsiveness is fast.

Furthermore, since the temperature of the air does not rise, energy efficiency is good. In addition, the temperature of the sheet material can be controlled by adjusting the amount of infrared radiation to keep the temperature of the sheet material at a predetermined temperature while detecting the temperature of the sheet material. It can be dried without any problem.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7. In this embodiment, a sheet-shaped photosensitive material is dried.

This drying device 10 includes a stand 12 formed of a frame. - This table 12 has a pair of side plates parallel to each other (however, the side plate on the near side is omitted in Fig. 1).
14 are installed upright, and between them there are 6 pairs of conveyor rollers 1
6 to 26 are arranged in parallel along the horizontal direction.

These transport roller pairs 16 to 26 are rotated by the driving force of a drive means (not shown), and transport the photosensitive material 28 in a substantially horizontal direction (from the left side to the right side in the first drawing). Further, on the upstream side of the pair of conveying rollers 16 (the side where the photosensitive material 28 is inserted into the drying device 10), there is a pair of conveying rollers 17 and a guide roller 1.
5 is placed. Further, a guide roller 19 is arranged downstream of the pair of transport rollers 26 (on the exit side of the photosensitive material 28 from the drying device 10). A mirror box 30 is disposed between each pair of transport rollers.

As shown in FIG. 2, the mirror box 30 is formed by molding a stainless steel plate into a cylindrical box shape, and the inner wall side is a reflective surface. The entire outer circumference of the mirror box 30 is covered with a box-shaped heat insulating material 32 (FIG. 1). Further, the upper part of the mirror box 30 is closed with a heat insulating material 34. A reflecting plate 31 made of the same material as the mirror box 30 is also arranged on the inner wall side of the heat insulating material 34, and on this reflecting plate 31, as shown in FIG.
A heater 36 is attached via an insulating material.

Note that the mirror box 30 and the reflecting plate 31 may be made of a material other than stainless steel that has good heat reflection, for example, the surface is plated with gold.

As shown in FIG. 3, the heater 36 is formed in a zigzag shape to increase its surface area. Invar can be used as the material for this heater, and the surface of the heater 36 is coated with a paint containing infrared emitting ceramic. Thereby, when the heater 36 is heated, infrared rays are emitted from the infrared ray emitting paint. This paint may be applied to only one side of the heater 36, or may be applied to both sides. This heater 36 is connected to a control device 52 as shown in FIG. 1, and the amount of heat of the heater 36 is controlled. In addition, the material of the heater 36 and others 1. : Nichrome, Kanthal, Kovar, Super Invar, etc. can be used.

The mirror box 30 and the reflecting plate 31 reflect the infrared rays emitted from the heater 36 and uniformly radiate the infrared rays onto the surface of the photosensitive material 28 . In addition, the dimension from the heater 36 to the lower end of the mirror box 30 (see Fig. 4) is such that the influence of the loss of heated air inside the mirror box 30 and the influence of the loss of radiated infrared rays can be tolerated. It is set to a certain length. Also, if the dimension L2 is long,
The temperature of the air within the mirror box 30 is locally increased by the heater 36, and thermal convection occurs due to the non-uniformity of the air temperature. Therefore, the dimension L2 is set to such an extent that no convection occurs.

Further, the heat insulating materials 32 and 34 prevent the heat of the mirror box 30 raised by infrared rays emitted from the heater 36 from escaping to the outside, thereby preventing heat loss due to thermal conduction.

Further, at the bottom of the conveyance path of the photosensitive material 28, a plurality of temperature detectors 38 are provided to detect the temperature of the photosensitive material 28 in a non-contact manner.
are arranged along the conveyance direction. This temperature sensor 3
8 includes a plurality of detection elements arranged in a direction perpendicular to the direction in which the photosensitive material 28 is transported. This temperature detector 38 is a thermal detector (bolometer-1 thermocouple, pyroelectric detector) or a photon (quantum) detector (PbS, InSb).

Intrinsic photoconductive cells such as HgCdTe), impurity-doped photoconductive cells in which gold, mercury, etc. are added to a germanium matrix, and the like can be used. The temperature detector 38 is the photosensitive material 2
The temperature of the photosensitive material 28 is detected by detecting the infrared rays emitted from the photosensitive material 8 . Furthermore, the temperature detector 38 is connected to the control device 52 .

A hood 40 is disposed directly above the temperature detector 38, and a reflection plate 42 is disposed above the hood 40.

This reflecting plate 42 receives radiation from the heater 38 and
The infrared rays transmitted through the photosensitive material 8 and the infrared rays emitted from the photosensitive material 28 are reflected and emitted to the photosensitive material 28 again, thereby improving the absorption efficiency of infrared rays into the photosensitive material 28. A plurality of through holes 44 are formed in the reflection plate 42 in correspondence with a plurality of detection elements of the temperature detector 38. Further, a shielding plate 46 is arranged in the through hole 44 of the reflecting plate 42 . These hood 40, reflector 42, and shielding plate 46 are connected to the temperature detector 3.
This is to prevent infrared rays from directly entering the heater 36 and allow only infrared rays emitted from the photosensitive material 28 to enter. The photosensitive material 28 is a reflection plate 42 and a shielding plate 4
It passes between 6 and 6.

A temperature detector 38 is disposed between each pair of conveyance rollers 16 to 26, respectively. In this embodiment, five stages from stage 0 to stage 4 are provided, and a mirror box 30 and a temperature detector 38 are provided for each stage.

Further, on the entrance side of the photosensitive material 28 of the drying device 10, there is a photosensitive material 2
A detector 48 is arranged to detect the passage of 8. This detector 48 is connected to the control device 52 and detects the leading edge of the photosensitive material 28. A detector 50 is disposed on the output side of the photosensitive material 20 of the drying device 10. This detector 50
is connected to the control device 52 and detects the rear end of the photosensitive material 28.

Next, the operation of this embodiment will be explained.

The photosensitive material 28 that has been developed by a developing device (not shown) is guided by a guide roller 15 and inserted between a pair of conveyor rollers 17, and then conveyed sequentially from stage 0 to stage 4 by pairs of conveyor rollers 16 to 26 and dried. The processed and dried photosensitive material 28 is guided by a guide roller 19 and discharged.

This drying will be explained according to the flowchart shown in FIG. In this embodiment, the conveyance speed of the photosensitive material 28 conveyed by the conveyance roller pairs 16 to 26 is constant.

In step 100, the tip of the photosensitive material 28 is connected to the detector 48.
It is determined whether or not it has been detected.

When the leading edge of the photosensitive material 28 is detected, the heater 36 of stage 0 is activated in step 102, and then the process proceeds to step 10.
3, the stage 0 heater 36 is at the target setting value P. It will be judged whether or not it has become. That is, the resistance value of the heater is calculated based on the voltage of the heater and the current flowing through the heater, and this resistance value is set to the target resistance value P0 corresponding to the target temperature of the heater (for example, 400°C in stage 0). The temperature of the heater is controlled by controlling the power. At this time, the target temperature of the heater is set to such a value that the temperature of the photosensitive material 28 being conveyed by heat radiation from the heater does not exceed the set temperature TS (for example, 55° C.) at stage 0, as shown in FIG. .

In step 104, it is determined whether the leading end of the photosensitive material 28 has been inserted into the stage 1 by determining whether it has been conveyed for a predetermined time, and if it is determined in the affirmative, step 10
5, the surface temperature of the photosensitive material 28 is detected by the detector 38 disposed on stage 0, and based on this detection result, the heater 36 of stage 1 is activated in step 106, and then the heater 36 of stage l is activated in step 107. 36 has reached the target setting value P1. That is, from the set temperature T of the photosensitive material 28 and the temperature of the photosensitive material detected by the temperature detector 38, the surface temperature of the photosensitive material is determined as the set temperature T,
A target resistance value P1 of the heater for controlling the heater is determined, and the resistance of the heater is the target resistance value P.

The temperature of the heater is controlled by controlling the power so that

In step 108, it is determined whether a predetermined period of time has elapsed to determine whether the leading edge of the photosensitive material 28 has reached stage 2, and in steps 109 to 111, it is determined based on the surface temperature of the photosensitive material 28 detected by the detector of stage l. The target resistance value P2 is set in the same manner as above, and the heater temperature is controlled in the same manner as above to maintain the temperature of the photosensitive material 28 at the set temperature T5. Hereafter, in the same manner as above, the target resistance value P
3, P4 is set and the temperature of the heater is controlled up to stage 4. Therefore, the surface temperature of the photosensitive material 28 is controlled to a set temperature T as shown in FIG. 6 while drying.

Since the photosensitive material 28 is gradually dried in each stage θ to stage 4 during this drying, the amount of heat required is smaller in the later stages, and as a result, the target resistance value of each heater is shown in FIG. As a result, from stage 1 onwards, it is gradually lowered.

In step 112, it is determined whether the detector 50 has detected the rear end of the photosensitive material 28, and if the rear end has not been detected, step 112 is repeatedly executed. Photosensitive material 28
When the detector 50 detects the rear end of the stage, the output of the heater of each stage is stopped in step 114.

In this embodiment, the output value of the heater for drying the photosensitive material 28 is controlled by detecting the surface temperature of the photosensitive material 28 using an infrared detector. However, the present invention is not limited to this.
The target resistance value of the heater may be controlled based on the measurement result.

[Effects of the Invention] As explained above, the sheet material drying apparatus according to the present invention radiates infrared rays to the surface of the sheet material and uses radiant heat to evaporate moisture and perform the drying process, resulting in high energy efficiency. It has excellent effects in that it has a quick response to temperature adjustment and does not overdry the sheet material.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of a sheet material drying apparatus according to the present invention, FIG. 2 is a perspective view showing a mirror box,
Figure 3 is a perspective view showing the heater and the reflector, Figure 4 is an enlarged cross-sectional view of a part of Figure 1 showing the relationship between the temperature detector and the mirror box, and Figure 5 is the heater of each stage versus drying time. FIG. 6 is a diagram showing the set surface temperature of the photosensitive material versus drying time, and FIG. 7 is a flowchart showing control for drying the photosensitive material. DESCRIPTION OF SYMBOLS 10... Sheet material drying device, 16-26... Conveyance roller pair, 30... Mirror box, 31... Reflection plate, 36... Heater, 38... Temperature detector.

Claims (1)

[Claims] (1) A sheet material drying device for drying sheet materials, which includes a conveyance means for conveying the sheet materials, an infrared radiation means for emitting infrared rays, and an infrared ray emitted by the infrared radiation means during conveyance. 1. A drying device for sheet material, comprising: a reflecting means for reflecting toward the surface of the sheet material.