JPH11153852A - Heating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hating device capable of more easily and highly precisely controlling the surface temp. of a heating medium by providing the heating device with the heating medium incorporated with a heat source inside and side plates for supporting the hating medium, providing the side plates with heating regions having almost the same temp. as that of the heating medium, and supporting the heating medium in the heating regions. SOLUTION: In this heating device, the center shaft 68a of a heating drum 68 is held by bearings 84 in the heating regions 86 heated to be almost the same temp. as that of the heating drum 68. Since such a constitution that the heating drum 68 is held by the heating regions 86 is adopted, the heat of the drum 68 never passes through the side plates 82 from the center shaft 68a. In other words, the transmission of the heat from the center shaft 68a is prevented to ideally insulate the side plates 82 from the drum 68 in heat. Thus, the surface temp. of the drum 68, that is, the heat source 78 can be controlled by considering only a timewise temperature fluctuation caused by heat development while neglecting the heat passing through the side plates 82.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of an apparatus for heating a sheet material using a heating medium, which is used, for example, in a heat development section of an image forming apparatus using a photosensitive heat development recording material.

[0002]

2. Description of the Related Art Conventionally, ultrasonic diagnosis, CT diagnosis, MR
Diagnostic images such as an I diagnosis and an X-ray diagnosis are recorded on a silver halide photographic light-sensitive material and developed into a hard copy. However, while silver halide photographic materials can provide high-quality images, they require wet development processing such as color development, fixing bleaching, and washing with water. There is also a problem that the maintenance of the (processor) is troublesome, and it is desired to output a hard copy by an image forming method that does not require a wet developing process.

As an image forming method that does not require wet processing,
Thermal image recording is known. As is well known, the thermal image recording uses a thermal head having a glaze in which heating elements are arranged in one direction (main scanning direction), and presses the glaze against the thermosensitive recording material. The image is recorded on the heat-sensitive recording material by generating heat in each heating element according to the recorded image while relatively moving in the orthogonal direction. The image quality of such thermal recording images has been greatly improved in recent years. Recently, in addition to recording of ultrasonic diagnostic images conventionally used, CT diagnosis, MRI diagnosis,
Use for applications requiring large and high-quality images, such as line diagnosis, is also being studied. However, in terms of recording density and gradation reproducibility, an image formed by exposing a silver halide photographic material with a light beam or the like is also advantageous.

As an image forming method which has solved such problems, attention has been paid to image recording using a photosensitive heat-developable recording material. A photosensitive heat-developable recording material is a recording material in which a color is formed by exposure and heating, or a color is stopped by exposure (to prevent color formation) and a non-exposed portion develops color by heating. A latent image is formed by imagewise exposing a heat-developable recording material, and the exposed or unexposed part is colored by heating the exposed recording material to obtain a hard copy on which an image is recorded. it can. According to the image recording using such a photosensitive heat development recording material, a high-definition high-quality image using a light beam scanning exposure or the like can be formed without performing a wet development process.

As a thermal developing device for performing thermal development in image formation using such a photosensitive thermal development recording material (hereinafter, referred to as a recording material), a heating drum including a heater such as a halogen lamp, 2/3 for heating drum
An apparatus using an endless belt wound around the circumference is known. In this heat developing apparatus, a recording material on which a latent image was formed by exposure was inserted between a heating drum and an endless belt, and the heating drum was rotated at a predetermined speed to thereby bring the recording material into close contact with the heating drum. In this state, the recording material is nipped and conveyed between the heating drum and the endless belt, so that the recording material is heated at a predetermined temperature for a predetermined time to perform thermal development.

The color density of a recording material depends on the amount of heat given by thermal development. Therefore, in order to form a high-quality image, it is necessary to uniformly apply a predetermined amount of heat to the entire surface of the recording material. It is preferred that it be maintained. However, the heat of the heating drum is taken away by various factors, and it is actually extremely difficult to always and entirely maintain the surface temperature of the heating drum at a predetermined temperature.

[0007]

As major factors for removing heat from the heating drum, there are heat taken away by the recording material by thermal development and heat transferred from the heating drum to the outside.

As described above, the recording material is thermally developed in a state in which the recording material is in close contact with the heating drum. However, since the recording material used for development is at a much lower temperature than the heating drum, Heat is deprived of the recording material and the surface temperature drops.
Further, when the surface temperature decreases, the output of the heating source built in the heating drum improves so as to keep the surface temperature at a uniform predetermined temperature. Here, the decrease in the surface temperature is different between a case where one sheet of the recording material is subjected to thermal development and a case where a large number of sheets of the recording material are continuously carried out. That is, the surface temperature of the heating drum has a heat distribution in which the amount of heat transferred to the recording material flourishes as it is in one-time thermal development. On the other hand, in the case where processing is performed continuously, the heater performs continuous heating at a high output, so that the surface temperature of the heating drum eventually becomes the heat deprived by the continuously supplied recording material. In addition to
The temperature distribution of the heating source becomes prosperous. That is, the control for maintaining the heating drum surface at a uniform predetermined temperature is completely different between the one-shot thermal development and the continuous thermal development.

On the other hand, the heating drum is supported by the side plate,
The temperature of the side plate depends on the environmental temperature, and is naturally much lower than the temperature of the heating drum. Therefore, the heat of the heating drum is transferred to the side plate and the like along the central axis, and the temperature at both ends tends to be lower than at the center.

That is, the surface temperature of the heating drum depends on factors such as heat release through the central axis, heat taken by the recording material to be subjected to thermal development, and the state of thermal development (continuous or single shot). It is complicated and fluctuates, and it is very difficult to always maintain a uniform and predetermined temperature over the entire surface irrespective of the state of thermal development.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a heating drum or the like suitably used for a heat developing section of an image forming apparatus using a photosensitive heat-developing recording material. A heating device for a sheet-like material using a heating medium, which can prevent heat from being transmitted from the heating medium to a side plate or the like that supports the heating medium, thereby eliminating fluctuations in the surface temperature of the heating medium caused by the heat. Another object of the present invention is to provide a heating device capable of controlling the surface temperature of a heating medium more easily and with high accuracy.

[0012]

In order to achieve the above object, the present invention comprises a heating medium having a heating source therein, and a side plate for supporting the heating medium, wherein the side plate comprises the heating medium. A heating device having a heating region having substantially the same temperature as a medium, wherein the heating medium is supported in the heating region.

Further, between the heating medium and the heating area,
Preferably, a heat insulating member is provided.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heating apparatus according to the present invention will be described in detail based on a preferred embodiment shown in the accompanying drawings.

FIG. 1 is a schematic view showing an example of an image forming apparatus using the heating device of the present invention. An image forming apparatus 10 (hereinafter, referred to as a forming apparatus 10) illustrated in FIG.
A device which is preferably used as a so-called medical imager for producing a print in which an image measured by a medical measuring instrument such as I is reproduced as a visible image,
Photothermographic recording material A (hereinafter referred to as recording material A) comprising a photothermographic image-forming layer formed on a support such as a film.
The recording material A is exposed imagewise with a light beam L modulated according to image data supplied from an image data supply source R such as an MRI, and a latent image is recorded. The recording material A is heated and developed to develop a color, and is output as a hard copy on which an image is formed.

As the recording material A that can be thermally developed by the heating device of the present invention, various recording materials of a thermal development type (thermochromic) capable of recording a latent image by exposure can be used. As an example, a photothermographic recording material having an image forming layer in which at least 50% of a binder is composed of latex and containing an organic silver salt and a reducing agent of an organic silver salt, a heat containing an electron-donating colorless dye Responsive microcapsules, a photothermographic recording material having an image forming layer containing a photopolymerization initiator, a compound having an electron acceptor and a polymerizable vinyl monomer in the same molecule, and an electron-donating colorless dye Examples thereof include photosensitive heat-developable recording materials having an image forming layer containing a thermoresponsive microcapsule, an electron-accepting compound, a polymerizable vinyl monomer, and a photopolymerization initiator. In addition, photosensitive heat-developable recording materials disclosed in JP-A-3-87827 and JP-A-4-21252 can also be suitably used.

The forming apparatus 10 for producing a print (hard copy) on which a visible image is formed in accordance with the image data supplied from the image data supply source R using such a recording material A is basically used. , A recording material supply unit 12, a width adjustment unit 14, and an image exposure unit 16 in the order of conveyance of the recording material A.
And a thermal developing section 18 using the heating device of the present invention, and a discharge tray 80. Although not shown in FIG. 1 in order to simplify the drawing and clarify the configuration, the forming apparatus 10 includes a conveying roller and a guide for conveying the recording material A in addition to the illustrated members. , Various sensors and the like are arranged as needed.

The recording material A is usually formed into a laminate (bundle) of a predetermined unit such as 100 sheets and wrapped in a bag, a band, or the like. And supplied to the forming apparatus 10 for image formation one by one. The recording material supply unit 12 (hereinafter, referred to as a supply unit 12) takes out one recording material A from the magazine 20 and places it at a downstream position (hereinafter, referred to as downstream) in the transport direction of the recording material A. At the site that supplies 14
Loading parts 22 and 24 and suction cups 2 arranged in each loading part
Sheet Feeding Means Using 6 and 28 and Supply Roller Pair 3
0 and 32, transport roller pairs 34 and 36, and transport guides 38, 40 and 42.

The loading sections 22 and 24 are sections for loading the magazine 20 containing the recording material A at a predetermined position.
The illustrated forming apparatus 10 includes two loading units 22 and 24.
Usually, recording materials A having different sizes (for example, half-cut size for CT and MRI, B4 size for FCR (Fuji Computed Radiography), etc.) are stored in both loading sections. The magazine 20 is loaded.

The sheet feeding means arranged in each loading section includes a suction cup 2
6 and 28, the recording material A is sucked and held, and the recording material A is conveyed by moving the suction cups 26 and 28 by a known moving means such as a link mechanism. And 32. The recording material A supplied to the supply roller pair 30 is guided by the conveyance guides 38, 40, and 42 while being conveyed by the conveyance roller pairs 34 and 36, and the supply roller pair 3
The recording material A supplied to the transport guides 40 and 4
The sheet is conveyed by the pair of conveying rollers 36 to the downstream width adjuster 14 while being guided to the second side.

The width shifter 14 aligns the recording material A in a direction perpendicular to the conveying direction (hereinafter, referred to as a width direction), so that the position of the recording material A in the main scanning direction in the downstream recording unit 16 is adjusted. This is a part where the recording material A is conveyed to the downstream image exposure unit 16 by the conveyance roller pair 44 after taking the so-called side resist. There is no particular limitation on the method of the side resist in the width shifter 14. For example, a resist plate that contacts one end surface in the width direction of the recording material A to perform positioning, and the recording material A is pushed in the width direction to move the end surface. Using a pressing means for bringing the recording material A into contact with the resist plate, and controlling the conveying direction of the resist material and the recording material A in the width direction and making the recording material A contact the resist plate in the same manner. Various known methods, such as a method using a guide plate or the like that can be moved according to the conditions, are exemplified. Note that the side resist (ie, exposure) may be a so-called center reference based on the center in the width direction of the recording material A, or a so-called end surface reference based on an end portion in the width direction of the recording material A.

The image exposing section 16 (hereinafter, referred to as the exposing section 16) is a portion for exposing the recording material A imagewise by light beam scanning exposure.
8 is provided.

FIG. 2 is a conceptual diagram of the exposure unit 16. The exposure unit 46 includes a light beam L modulated according to a recorded image.
Is a known light beam scanning device that deflects light in a main scanning direction (a direction perpendicular to the paper surface in FIGS. 1 and 2) and enters a predetermined recording position X. The control unit 52 includes a data processing unit 53, a polygon mirror 54 serving as an optical deflector, an fθ lens 56, and a falling mirror 58. In addition, the exposure unit 46 further includes a collimator lens or a beam expander for shaping the light beam L emitted from the light source,
Various members used for the light beam scanning device, such as a surface tilt correction optical system and an optical path changing mirror, are arranged as necessary.

The light source 50 is a light source that emits a light beam L in a narrow wavelength range according to the spectral sensitivity characteristics of the recording material A.
Image data from an image data source R such as MRI or CT is sent to the data processing unit 53. Data processing unit 53
Performs necessary image processing such as correction according to calibration on the supplied image data,
To supply. The image data processed by the data processing unit 53 is sent to the exposure control device 52. Exposure control device 52
Drives the light source 50 in accordance with the supplied image data, that is, the recorded image, and emits a light beam L modulated in accordance with the image data.

In the forming apparatus 10, the light beam L is modulated by a known method, for example, by pulse (width or number) modulation or intensity modulation. In the illustrated example, the light beam L is modulated in accordance with the recorded image by direct modulation, in which the exposure control device 52 controls the driving of the light source 50 to perform modulation. External modulation using an optical modulator), an EOM (electro-optical modulator), or a spatial modulation element such as a liquid crystal shutter array may be used.

The light beam L thus modulated and emitted from the light source 50 is deflected in the main scanning direction by the polygon mirror 54, is modulated by the fθ lens 56 so as to form an image at the recording position X, and falls. The optical path is changed by the mirror 58 and the light enters the recording position X. The forming apparatus 10 in the illustrated example is an apparatus for recording a monochrome image, and the exposure unit 46 has only one light source 50. However, when the present invention is used for recording a color image, for example, a color photosensitive material is used. An exposure unit having three light sources that emit light beams having wavelengths according to the spectral sensitivity characteristics of R (red), G (green), and B (blue) is used.

On the other hand, the sub-scanning conveying means 48
A pair of transport rollers 60 arranged with the (scanning line) interposed therebetween
The recording material A is conveyed in the sub-scanning direction (the direction of arrow a in FIG. 2) orthogonal to the main scanning direction while holding the recording material A at the recording position X by the conveying roller pairs 60 and 62. Here, as described above, since the light beam L modulated according to the recorded image is deflected in the main scanning direction, the recording material A is two-dimensionally scanned and exposed by the light beam, and the latent image is recorded. Is done.

The recording material A on which the latent image has been recorded in the exposure section 16 is then transported upward by transport roller pairs 64 and 66 and the like, and is transported to the thermal developing section 18. The heat developing unit 18 uses the heating device of the present invention, and heats the recording material A to perform heat development to make a latent image a visible image. 70, a separation claw 72, support rollers 74a to 74d for supporting the endless belt 70, and a pair of introduction rollers 76.

The heating drum 68 is a drum having a built-in heating source 78, the surface of which is heated and held at a temperature corresponding to the heat development temperature of the recording material A by a known means.
8a is rotatably held by a bearing 84 on the side wall 82 and is engaged with a rotation drive source (not shown) (see FIG. 3). The heating source 78 of the heating drum 68 is not particularly limited, and various known heating means can be used as long as the entire surface (side surface) of the heating drum 68 can be heated to a uniform temperature. And the like, and a heat source such as a heating light source and a heater, and further, an annular film heater and the like. Further, it is preferable that the output (temperature) of the heating source 78 can be adjusted in the axial direction of the heating drum. In the illustrated example, the center shaft 68a and the heating drum 68
Are fixed, and both rotate. However, the present invention is not limited to this, and the central axis may be fixed to the side plate, and only the heating drum 68 may be configured to rotate with respect to the central axis. .

The endless belt 70 has support rollers 74a, 74
The recording material A is supported and stretched by four rollers 4b, 74c, and 74d and is pressed so as to be wound around the heating drum 68, is rotated by the heating drum 68, and pinches and conveys the recording material A together with the heating drum 68. . Peeling nail 72
Is for peeling off the recording material A from the heating drum 68, and is configured to lightly contact and separate from the heating drum 68 in accordance with the conveyance of the recording material A by the heating drum 68.

The recording material A conveyed to the thermal developing section 18 by the conveying roller pair 66 is nipped and conveyed by the introducing roller pair 76, conveyed between the heating drum 68 and the endless belt 70, and rotated by the heating drum 68. The heating drum 68 and the endless belt 70
The latent image recorded by exposure is conveyed in a state in which the latent image is thermally developed by the heat of the heating drum 68 and becomes a visible image. When the leading end of the recording material A is conveyed to the vicinity of the peeling claw 72, the peeling claw 72 lightly contacts the heating drum 68,
The recording material A penetrates between the heating drum 68 and the recording material A, and is separated from the heating drum 68.

Here, in the heat developing section 18 according to the heating device of the present invention, the side plate 82 holding the heating drum 68
Are also heated to substantially the same temperature as the heating drum 68.

FIG. 3 schematically shows the heating drum 68 and the side plate 82. As shown in FIG.
Is rotatably held on the side plate 82 by a bearing 84. Here, the bearing 84 is disposed in a heating region 86 of the side plate 82, and the heating region 86 of the side plate 82 and the outside thereof are separated by a heat insulating material 88. A heating source (not shown) such as a film heater is attached to the heating area 86 and is heated to substantially the same temperature as the heating drum 68.

In a conventional heating device using a heating drum,
Since the heat of the heating drum is transmitted from the central axis to the side plate, the surface temperature of the heating drum fluctuates not only due to the temperature decrease due to the recording material A (the material to be heated) but also due to the release of heat from the central axis. However, it is very difficult to always maintain a uniform and predetermined temperature over the entire surface because the elements vary in a complicated manner. On the other hand, in the heating device of the present invention, the center shaft 68a of the heating drum 68 is held by the bearing 84 in the heating area 86 heated to substantially the same temperature as the heating drum 68. As is well known, heat is transferred from a high temperature to a low temperature. Therefore, by having a configuration in which the heating drum 68 is held in the heating region 86, the heat of the heating drum 68 flows from the central shaft 68a to the side plate 82. Nothing. In other words, the flow of heat from the central shaft 68a is prevented and the side plate 82
And the heating drum 68 can be ideally insulated.

Therefore, according to the heating apparatus of the present invention, as a factor of the surface temperature fluctuation of the heating drum 68, only the heat absorbed in the recording material A (the material to be heated) is considered, ignoring the heat flowing through the side plate 82. That is, the surface temperature of the heating drum 68, that is, the heating source 78 may be controlled in consideration of only the temporal temperature fluctuation due to thermal development. Therefore, according to the present invention, the heating drum 68 can be stably and easily controlled.
Can be maintained at a predetermined temperature which is uniform over the entire surface. For example, when used in a thermal developing section of an image forming apparatus as shown in the figure, the thermal development of the recording material A is uniformly performed over the entire surface. By performing the process at a predetermined temperature, it is possible to stably form a high-quality image that is appropriately colored.

The material for forming the heating region 86 of the side plate 82 is not particularly limited, and may be formed of a material having an appropriate heat transfer property, such as a metal such as stainless steel or iron. In the illustrated example, the heating region 86 is thermally separated from the outside by the heat insulating material 88. However, the heat insulating material 88 is unnecessary if the heat of the heating region 86 is not transmitted to the outside. There is no particular limitation on the heating means of the heating area 86, and various known methods such as a rubber heater and a film heater can be used. In addition,
The heating region 86 does not need to be controlled with high precision, and may be any temperature as long as it is approximately the same as the surface temperature of the heating drum 68.
The temperature may be about 10 ° C., particularly about ± 1 ° C. to 3 ° C.

In the heat developing section 18 shown in the drawing, as a preferred embodiment, a heat insulating bearing is used as the bearing 84.
In this manner, by arranging the heat insulating material between the heating drum 68 and the heating area 86 and thermally separating them, when the surface temperature of the heating drum 68 is reduced by the recording material A, the heating area is reduced. It is possible to preferably prevent heat from flowing from the heating drum 86 to the heating drum 68 and more appropriately control the surface temperature of the heating drum 68. The heating drum 68 and the heating area 86
When a heat insulating material is arranged between the heating region 86 and the heat insulating material, the heat insulating material may be used to hold the bearing. Alternatively, a heat insulating material may be arranged between the bearing and the heating area 86 in an annular shape. In this case, there is no need to heat the space between the bearing and the heat insulating material, and the space between the bearing and the heat insulating material is heated by the heating drum 68, and as a result, a heating region is formed.

As the heat-insulating bearing, various known heat-insulating bearings made of resin, ceramic, or the like can be used. As the heat insulating material, various known materials such as resin and ceramic can be used.

The temperature of the heating drum 68 and the time for thermal development are not limited, and may be determined as appropriate according to the recording material A to be used. Further, the heat development time may be adjusted by changing the conveyance speed according to the type of the recording material A, or by stopping the conveyance after the recording material A is completely stored.

As described above, the recording material A peeled off from the heating drum 68 by the peeling claw 72 after the thermal development by the heating drum 68 is finished is conveyed to the outside of the apparatus, and becomes a hard copy from which an image is reproduced. It is discharged to the tray 80.

FIG. 4 shows another example of the heating means used in the heating device of the present invention. This heating means 90 is used in place of the heating drum 68 in the heat developing section 18 of the forming apparatus 10. The heating means 90 includes a cylindrical heating medium 92.
A heating source 94 such as a rubber heater for heating the heating medium 92 from the inside; and a heat transfer member 9 loosely fitted to the heating medium 92.
6. In the illustrated example, the heating medium 92 does not rotate and is fixedly held in the heating area of the side plate 82 by a known means. The heat transfer member 96 is a cylindrical member or an endless belt rotatable around the heating medium 92 with its inner surface slidably contacting the side surface of the heating medium 92, and is made of a material having sufficient thermal conductivity such as aluminum. You. The surface of the heating medium 92 (heat transfer member 96)
(Inner surface) is coated with heat transfer grease to make the sliding between them easy and smooth.

In the heating means 90 in the illustrated example, the heat transfer member 96 rotates around the heating medium 92, and pinches and conveys the recording material A together with the endless belt. To thermally develop the recording material A. The method of rotating the heat transfer member 96 is not particularly limited, and a known method such as an idler drive or a belt drive can be used.

Although the heating device of the present invention has been described in detail above, the present invention is not limited to the above embodiment, and various improvements and modifications may be made without departing from the gist of the present invention. Of course.

For example, the thermal developing device in the illustrated example uses an endless belt to pinch and convey the recording material A. In addition to this, a nip roller that is aligned with the heating drum and abuts on the side surface is arranged. Then, the recording material A may be nipped and conveyed by the heating drum and the nip roller. Further, the above example is an example in which the heating device of the present invention is used in a heat development section of an image forming apparatus using a photosensitive heat development recording material.
The heating device of the present invention may also be used in various other forms, such as pre-heating and post-heating of image formation using a heat-sensitive recording material, such as a heat fixing unit of an electrophotographic copying machine or a printer, a drum for heat sealing, and the like. It can be suitably used as a heating means for a sheet-like material.

[0045]

As described in detail above, according to the present invention, in a heating apparatus for heating a sheet material using a heating medium, the flow of heat from the heating medium to the side plates is cut off.
With simple control, the surface temperature of the heating medium can be kept substantially uniform over the entire surface.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an image forming apparatus using an example of a heating device of the present invention.

FIG. 2 is a schematic diagram of an image exposure unit of the image forming apparatus shown in FIG.

FIG. 3 is a view schematically showing holding of a heating drum on a side plate.

FIG. 4 is a view conceptually showing another example of the heating means used in the heating device of the present invention.

[Explanation of symbols]

Reference Signs List 10 (Image) forming apparatus 12 (Recording material) supply unit 14 Width adjustment unit 16 (Image) exposure unit 18 Thermal development unit 20 Magazine 22, 24 Loading unit 26, 28 Suction cup 30, 32 Supply roller pair 34, 36, 44, 60, 62, 64, 66 Conveying roller pair 38, 40, 42 Conveying guide 46 Exposure unit 48 Scanning conveying means 50 Light source 52 Exposure control device 53 Data processing unit 54 Polygon mirror 56 fθ lens 58 Falling mirror 68 Heating drum 70 Endless belt 72 peeling claw 74a, 74b, 74c, 74d support roller 76 introduction roller pair 80 tray 82 side plate 84 bearing 86 heating area 88 heat insulating material 90 heating means 92 heating medium 94 heating source 96 heat transfer member A recording material

Claims (2)

[Claims] 1. A heating medium having a built-in heating source therein, and a side plate supporting the heating medium, wherein the side plate has a heating region at substantially the same temperature as the heating medium. And a heating device supported within the heating region. 2. The heating device according to claim 1, wherein a heat insulating member is disposed between the heating medium and the heating area.