JP2676636B2 - Heat development device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heating and developing apparatus that heats and develops a photosensitive material by bringing the photosensitive material into contact with a peripheral surface of a heating drum that is driven to rotate.

[Prior Art] Various types of photosensitive materials are known for developing a latent image formed on a photosensitive material by heat development.

As a heating and developing device, for example, there is a system in which a photosensitive material is wound around a peripheral surface of a heating drum that is rotationally driven, and the photosensitive material is brought into contact with the heating drum for a predetermined time while carrying out the heating and developing.

In order to convey the photosensitive material along the peripheral surface of the heating drum, for example, a plurality of nip rollers that contact the peripheral surface of the heating drum are provided, and the heating drum and the nip roller are driven to rotate. A guide member is provided between the nip rollers around the heating drum so that the photosensitive material is in contact with the peripheral surface of the heating drum between the nip rollers, and the guide member guides the photosensitive material along the peripheral surface of the heating drum.

It is preferable that the guide member is configured to guide the photosensitive material along the peripheral surface of the heating drum and to bring the photosensitive material into close contact with the peripheral surface of the heating drum so that the photosensitive material is uniformly heated.

[Problems to be solved by the invention]

When the support of the photosensitive material is made of a hygroscopic material such as paper, it absorbs a predetermined amount of moisture in the air and absorbs a large amount of moisture in a high humidity atmosphere.

When a light-sensitive material containing such water is heated by a heat-developing device, the water in the light-sensitive material evaporates during heat-development. When the photosensitive material is in close contact with the peripheral surface of the heating drum, the water vapor evaporated from the drum contact surface of the photosensitive material is not discharged, but is covered by the photosensitive material and the peripheral surface of the drum.

Then, when the water vapor is encapsulated in the photosensitive material and the drum peripheral surface and partially stays, the photosensitive material is overdeveloped due to the influence of the water vapor, and the concentration of the photosensitive material is partially increased. In particular, when the photosensitive material is conveyed at a high speed, the difference in image density is remarkable.

Therefore, there is a problem that the photosensitive material is not heated and developed uniformly due to the influence of water vapor encapsulated by the photosensitive material and the peripheral surface of the drum, and the density of the image obtained by the development is not constant.

A device for solving such a problem is disclosed in
There is a heat developing device described in JP-A-59-104648. This device has a structure in which holes or slits are formed in the heat transfer member and water vapor generated from the front and back of the photosensitive material is discharged from the holes or slits. However, since the heat transfer means has holes or slits, the structure of the heat transfer means is complicated and it is difficult to manufacture the heat developing device.

An object of the present invention is to solve the above-mentioned problems, and it is possible to discharge water vapor generated from a photosensitive material with a simple structure and uniformly heat the photosensitive material by a heating drum, thereby obtaining a good image. An object of the present invention is to provide a heat developing device which can be used.

[Means and actions for solving the problem]

The above object of the present invention is to provide a heat developing device for heating and developing a photothermographic material by bringing the photothermographic material into contact with the peripheral surface of a rotating driven heating drum, and sandwiching the photosensitive material with the peripheral surface of the heating drum. And a guide means for urging and guiding the photosensitive material to the peripheral surface of the heating drum, and is a partial area in the circumferential direction of the heating drum in the area where the guide means and the heating drum face each other. And a guide means, an air gap is provided in the axial direction.

That is, in the area where the guide means and the heating drum face each other, a gap is provided in the axial direction between a part of the circumferential direction of the heating drum and the guide means, so that the photosensitive material urged by the heating drum is temporarily The urging force is released, and a slight gap is generated between the photosensitive material and the heating drum. Then
The water vapor evaporated from the contact surface of the photosensitive material on the heating drum does not stay between the photosensitive material and the heating drum, but is discharged along the axial direction of the heating drum through the gap created between the photosensitive material and the heating drum. It

Therefore, the photosensitive material is not overdeveloped due to the influence of water vapor, and the photosensitive material is uniformly heated and developed by the heating drum, and an image having a uniform density can be obtained on the photosensitive material. The present invention is particularly effective when the conveying speed of the photosensitive material is 180 mm / s or more and the heating time is 0.7 seconds or less, and the amount of heat applied to the photosensitive material per unit time is small.

The photothermographic material of the present invention may be of any recording system such as exposure and fixing as long as it is a photosensitive material that requires heat treatment.

As the photothermographic material, for example, JP-A-59-190886
There is a diazo photosensitive material having a genus containing a microcapsule containing a diazonium salt on a support, a coupler, and a base described in Japanese Patent Application Laid-Open No. H10-209,036. These form a latent image corresponding to the document by exposure, and are developed by heating.

(Embodiment)

Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic configuration diagram of a copying apparatus using a diazo photosensitive material. This copying apparatus has a configuration in which an image on a photosensitive material is colored by dry development.

The copying apparatus carries in and discharges the document C,
A document transport unit 32 for repeatedly circulating the same document C in the apparatus, an exposure unit 34 for exposing an image on a photosensitive material A superposed on the document C, and a developing unit 36 for heating and developing the document C after exposure; It has.

The document transport unit 32 includes a plurality of transport belts 40 wound around the hollow guide drum 38 in parallel, and further includes a belt.
With another belt 42 stretched opposite to 40, both belts 4
The document C is nipped and conveyed by rotating and driving 0 and 42.

A cassette 2 containing a photosensitive material A is loaded below the document conveying section 32. The photosensitive material A in the cassette 2 is
The paper feed roller 30 is synchronized with the original C to be conveyed.
Are supplied one by one to the superimposing section 44 and superimposed on the original C.

The photosensitive material A superimposed on the document C is transported by the transport roller 30 to the exposure section 34.

The exposure unit 34 includes an exposure lamp 48 including a fluorescent lamp 46.
And an exposure lamp 48 and a belt 52 supported by four belt supporting rollers 50 and wound around substantially three quarters of the peripheral surface of the exposure lamp 48. Then, the exposure lamp 48 and the belt 52 are driven to rotate, and while the document C and the photosensitive material A superposed between the exposure lamp 48 and the belt 52 are held and conveyed, the light from the exposure lamp 48 A document image is projected on the photosensitive material A to form a latent image.

The original C and the photosensitive material A after the exposure are separated and sucked in opposite directions by a suction unit (not shown) in the separation unit 54. The photosensitive material A is placed on the original C
Is transported to the developing unit 36.

The developing unit 36 includes a hollow cylindrical heating drum 58 having a halogen lamp 56 therein, and three transport rollers 60 abutting on the peripheral surface of the heating drum 58. Guide means 62 for guiding the photosensitive material A in contact with the peripheral surface of the heating drum 58 is provided between the transport rollers 60. The photosensitive material A is heated and developed while being nipped and transported by the heating drum 58 and the transport roller 60, and the latent image on the photosensitive material A is visualized.

In the developing section 36, the photosensitive material A can be transported by an endless belt wound around the peripheral surface of the heating drum 58 instead of the transport roller 60.

The photosensitive material A after the development is discharged from the discharge port 64 and slides on the discharge tray 66.

On the other hand, the original C separated from the photosensitive material A is
, Or circulates along the guide drum 38, and is used again for copying in the same process as described above.

FIG. 2 is a sectional view of the heating and developing unit 36 according to the embodiment of the present invention.

Three transport rollers 60a to 60c are in contact with the peripheral surface of the heating drum 58, and the first transport rollers 60a to 60c
The transport roller 60a is a hygroscopic roller such as a sponge, and has a heater 90 inside. Also, the second transport roller 60b
The third transport roller 60c is made of hard rubber. The axial direction of the second transport roller 60b is slightly oblique to the axial direction of the heating drum 58, and the second transport roller 60b and the heating drum 5
8 and 8 are close to each other in the axial direction.

 Provided between the first transport roller 60a and the second transport roller 60b
Guide means 62 are curved along the peripheral surface of the heating drum 58
Elastic material support member 92 and slightly above the peripheral surface of heating drum 58
An elastic material 94 having a curved surface with a small curvature and a sheet 96
Become. The support member 92, the elastic material 94, and the sheet 96 are made of a photosensitive material.
The width is slightly larger than the width A. Support member 92
An elastic material 94 such as felt or soft rubber is firmly attached to the inner surface of the
Have been. Further, the inner surface of the elastic material 94 is covered to cover the polytetraflour.
Polyethylene (eg Teflon ) Fluorine resin
The sheet 96 is provided, and the sheet-feeding-side end portion and the sheet-delivery-side end portion
The part is fixed to the support member 92.

The carry-in end of the elastic member 94 is located slightly in the carry-out direction from the sheet fixing end of the support member 92, and the carry-in end of the sheet 96 is inclined. Therefore, the photosensitive material A transported by the transport roller 60a easily enters between the heating drum 58 and the sheet 96 along the inclined surface of the sheet 96.

The curved surface of the elastic material 94 has a slightly smaller curvature than the peripheral surface of the heating drum 58, and the heating drum 58 is substantially at the center in the circumferential direction.
And a gap is formed between them. In this embodiment, the diameter of the heating drum 58 is 114 mm, and the gap in this case is preferably about 3 to 7 mm.

Further, the guide means 62 having the same structure is provided between the second transport roller 60b and the third transport roller 60c.

The photosensitive material A supplied to the heating and developing section 36 is first nipped and conveyed by the first conveying roller 60a and the heating drum 58.
The temperature of the heating drum 58 is preset to 150 by the halogen lamp 56.
The temperature of the first transport roller 60a is maintained at 150 ° C. by the heater 90. First transport roller 6
The photosensitive material A sandwiched between 0a and the heating drum 58 is heated by the first transport roller 60a, and part of the water contained in the support is evaporated.

The evaporated moisture is absorbed by the first transport roller 60a, which is hygroscopic. The first transport roller 60a dries after the transport of the photosensitive material A and before the subsequent photosensitive material A is supplied.

The photosensitive material A is then transferred to the heating drum 58 by the guiding means 62.
Heat development is performed while being guided along the peripheral surface.

Since the sheet 96 is made of a fluororesin, the heating drum 58
When the photosensitive material A moves together with the heating drum 58 due to the rotation of the transport rollers 60a to 60c, the photosensitive material A
And sliding smoothly.

The supporting member 92 is fixed in position with respect to the heating drum 58, and the elastic material 94 provided on the supporting member 92 urges the sheet 96 toward the heating drum 58, so that the supporting member 92 is sandwiched between the heating drum 58 and the sheet 96. The exposed photosensitive material A is brought into contact with the heating drum 58 and is guided and heated. The urging force of the sheet 96 by the elastic material 94 depends on the material and thickness of the elastic material 94 and the heating drum of the support member 92.
It can be adjusted by the mounting position with respect to 58.

When the photosensitive material A is conveyed along the peripheral surface of the heating drum 58, the photosensitive material A is urged by the heating drum 58 to be heated. At this time, the moisture contained in the photosensitive material A evaporates from the front and back of the photosensitive material A. On the other hand, the photosensitive material A is temporarily lifted from the peripheral surface of the heating drum 58 because of its rigidity because the biasing force of the elastic material 94 is temporarily released when the leading end of the photosensitive material A is transported in the area of the void 93. Then, as it is conveyed thereafter, it is urged again by the heating drum 58 to come into close contact with the peripheral surface of the heating drum 58. Since a part of the photosensitive material A floats in the width direction, the moisture evaporated from the contact surface (emulsion surface) with the heating drum 58 by heating is
From the gap between the heating drum 58 and the photosensitive material A, the photosensitive material 58
Is discharged to both ends in the width direction of. Further, the water vaporized from the surface of the support of the photosensitive material A is also discharged from the gap between the photosensitive material A and the sheet 96 to both ends of the photosensitive material A in the width direction.

Further, since the urging force of the elastic material 94 decreases from both ends in the circumferential direction toward the central void 93, even if moisture evaporates from the portion of the photosensitive material A that is in close contact with the heating drum 58, the generated steam urges. In the direction of decreasing the space, that is, in the direction of the space 93, and is discharged from the space 93. Therefore, it is preferable that the void 93 is formed at the center of the elastic member 94 in the circumferential direction, but the invention is not limited to this, and the void 93 may be formed near the end portion in the circumferential direction.

Further, in the present embodiment, the curvature of a part of the curved surface of the elastic member 94 facing the heating drum 58 is made slightly smaller than the curvature of the heating drum 58 to form the void 93, but as shown in FIG. In addition, by forming a notch 95 in the elastic member 94,
93 may be formed, and the bias of the photosensitive material A may be temporarily released.

In this embodiment, the photosensitive material A is conveyed at a speed of 22 to 220 mm / s. When the photosensitive material A is conveyed at a low speed, the total amount of heat given to the photosensitive material A is large and the photosensitive material A
Since the total density of the above is high, even if there is uneven density due to overdevelopment, it does not appear significantly. However, when the photosensitive material A is transported at a high speed of 180 mm / s or higher, the overall density is low, and therefore, if there is partial over-development, uneven density becomes noticeable.

Since the water vapor generated from the photosensitive material A is discharged from the air gap 93 by providing the air gap 93 between the peripheral surface of the heating drum 58 and the elastic material 94 as in the above configuration, the photosensitive material conveying speed is high. Even if there is, overdevelopment due to steam is prevented,
The image density does not become non-uniform.

In the above-described embodiment, the second conveying roller 60b may be omitted, and the same guiding means 62 as the above-mentioned configuration may be provided for guiding the photosensitive material A from the first conveying roller 60a to the third conveying roller 60c.

 FIG. 4 is a side view of another embodiment of the present invention.

The heating and developing section shown in FIG. 4 is different from the heating and developing section shown in FIGS. 2 and 3 in that the photosensitive material A is conveyed. The heating drum 58 containing the halogen lamp 56 has 4
Endless belt stretched over two belt support rollers 70
71 is wound around the circumference of about 3/4. Then, the endless belt 71 is rotationally driven to convey the photosensitive material A, which is urged by the heating drum 58 to be heated and developed.
Therefore, the endless belt 71 also serves as the guiding unit and the conveying unit in the present invention.

The width of the endless belt 71 is formed longer than the axial length of the heating drum 58, and the heating drum 58 is provided on both sides of the heating drum 58.
A biasing release roller 72 opposed to the heating drum 58 is provided so as to project radially outward from the peripheral surface of the heating drum 58. The endless belt 71 is supported by the urging release roller 72 so that the endless belt 71 partially floats from the peripheral surface of the heating drum 58, and a gap 93 is formed between the heating drum 58 and the endless belt 71.
Is formed.

When the photosensitive material A is nipped and conveyed by the heating drum 58 and the endless belt 71, the bias to the heating drum 58 is temporarily released in the gap 93 and floats from the circumferential surface of the heating drum 58 in the axial direction. Therefore, the moisture evaporated from the photosensitive material A passes through the void 93 and is heated by the heating drum.
It is discharged to both sides of 58 and does not adversely affect the photosensitive material A.

〔The invention's effect〕

According to the present invention, in the area where the guide means and the heating drum face each other, a gap is provided in the axial direction between the guide means and a partial area in the circumferential direction of the heating drum, so that the heating drum is urged. The photosensitive material is temporarily de-energized, and a slight gap is created between the photosensitive material and the heating drum. Then, the water vapor evaporated from the contact surface of the photosensitive material with the heating drum does not stay between the photosensitive material and the heating drum, but passes through the gap created between the photosensitive material and the heating drum and along the axial direction of the heating drum. Is discharged.

Therefore, the photosensitive material is not overdeveloped due to the influence of water vapor, and the photosensitive material is uniformly heated and developed by the heating drum, and an image having a uniform density can be obtained on the photosensitive material.

[Brief description of the drawings]

 FIG. 1 is a schematic sectional view of a copying machine to which the present invention is applied, and FIG. 2 is a sectional view of an embodiment of the present invention. FIG. 3 is a sectional view of another embodiment of the present invention, and FIG. 4 is a side view of yet another embodiment of the present invention. Reference numeral in the figure: 2 ... Paper feed cassette 30 ... Paper feed roller, 32 ... Original transport section 34 ... Exposure section, 36 ... Development section 38 ... Guide drum, 39 ... Holes 40, 42 ... Transport Belt 44 …… Overlap part, 46 …… Fluorescent lamp 48 …… Exposure lamp 50 …… Belt support roller 52 …… Conveyor belt, 54 …… Peeling part 56 …… Halogen lamp 58 …… Heating drum, 60 …… Conveyor roller 62 ...... Guide means 64 ...... Ejection port 66 …… Ejection tray 68 …… Fan 70 …… Belt support roller 71 …… Endless belt 72 …… Bias release roller 90 …… Heater, 92 …… Support Member 93 …… Void 94 …… Elastic material, 96 …… Sheet A …… Photosensitive material, C …… Original

Claims (1)

(57) [Claims] 1. A heating and developing device for heating and developing a photosensitive material by bringing the photosensitive material into contact with the peripheral surface of a heating drum that is rotationally driven, and conveys the photosensitive material while sandwiching the photosensitive material with the peripheral surface of the heating drum. And a guide means for urging and guiding the photosensitive material to the peripheral surface of the heating drum, and a partial area in the circumferential direction of the heating drum and the guide means in the area where the guide means and the heating drum face each other. A heat-developing apparatus having a gap between and in the axial direction.