JPH11102058A - Heat developing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat developing device capable of obtaining a recorded image which does not have density irregularity, in which color development is sufficiently performed with desired density, and whose quality is high. SOLUTION: This device has a first sensor 90 which is provided corresponding to an area where a photosensitive heat developable recording material A can pass in the width direction of the surface of a heating drum 68, and which detects the temperature T1 of the passing area on the surface of the drum 68, a second sensor 92 which is provided corresponding to an area where the material A never passes in the width direction of the surface of the drum 68, and which detects the temperature T2 of the non-passing area on the surface of the drum 68, and a control part 94 which stops energizing a heating element 69 at least in either case that the detected temperature T1 of the sensor 90 exceeds a set temperature TA or that the detected temperature T2 of the sensor 92 exceeds a specified upper limit temperature TB(TB>TA), and which performs energizing the element 69 in other case.

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 a heat developing apparatus for performing heat development by bringing a photosensitive heat development recording material imagewise exposed into contact with a heating drum.

[0002]

2. Description of the Related Art Conventionally, ultrasonic diagnosis, CT diagnosis, MR
Images taken by I diagnosis, X-ray diagnosis and the like are recorded on a silver halide photographic light-sensitive material to form 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 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. The photosensitive heat-developable recording material is a recording material that develops a color by heating an exposed area or a non-exposed area, and forms a latent image by imagewise exposing the photosensitive heat-developed recording material by a light beam or the like, By heating the exposed photosensitive material, an exposed area or a non-exposed area is colored and visualized, and a hard copy in which an image is recorded as a visible image can be obtained. 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.

[0005]

Incidentally, thermal development in image formation using a photosensitive heat-developable recording material (hereinafter, referred to as a recording material) is usually performed by heating the recording material using a heater or the like. Will be As a specific example, a drum having a built-in heater such as a halogen lamp and an endless belt driven by a drum which is wound around the drum by about 2/3 turn are used. A method of carrying out heat development at a predetermined temperature for a predetermined time by inserting the sheet between the belt and the sheet and conveying the sheet and discharging the sheet from the opposite end is exemplified. On the other hand, as a recording material, an image forming layer having photosensitivity and heat development (thermochromic) was formed using a polyethylene terephthalate (PET) film or the like as a support, and various layers such as a protective layer were formed as necessary. Things.

Here, the temperature control of the drum is usually provided with a temperature sensor for detecting the temperature of the drum surface. When the detected temperature is higher than the set temperature, the heater is turned off, and the detected temperature is lower than the set temperature. This is done by turning on a heater, but such a temperature sensor measures the temperature of the center of the drum in the width direction (hereinafter referred to as the drum center) which is most easily cooled by contact with the recording material on the drum surface. Is provided at one location.

However, it is difficult to make the temperature of the drum surface strictly uniform in the width direction, and a somewhat uneven temperature distribution occurs. That is, since the width of the drum is designed to be wider than the width of the recording material, a region where the recording material does not always pass in the width direction of the drum occurs. Therefore, as shown in FIG. 4A, even when the temperature of the drum is uniformly controlled in the width direction, when a low-temperature recording material comes into contact with the drum, as shown in FIG. While the central portion of the drum, which is the contact portion, is cooled, both end portions in the width direction of the drum (hereinafter referred to as both end portions of the drum) to which the recording material does not contact are kept at a high temperature without being directly cooled. In addition, the temperature in the center of the drum becomes low,
There is a problem that a non-uniform temperature distribution is formed.

[0008] However, despite the uneven temperature distribution in the width direction, if the temperature of the drum is controlled by detecting only the center of the drum as described above, the temperature of the center of the drum becomes lower than the set temperature. Since the heating is continued as long as the temperature is low, even if the temperature at both ends of the drum is already sufficiently high, a situation occurs in which the drum is further heated, which further promotes the non-uniformity of the temperature distribution in the width direction of the drum. For this reason,
When the recording material comes into contact with the drum, both ends in the width direction of the recording material are heated at a temperature equal to or higher than the set temperature, and there is a problem that density unevenness may occur in the width direction of the recorded image.

In particular, in medical applications as described above, a thick PET film or the like is used as a support in order to obtain the same quality as conventionally used silver halide photographic light-sensitive materials. In order to develop a color properly, it is necessary to apply a large amount of heat compared to the amount of heat originally required for development, and since the heat capacity is large, the unevenness of the temperature distribution generated in the heating drum tends to be remarkable. There was a problem.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art. In a heat developing apparatus for performing heat development by bringing a photosensitive heat-developable recording material imagewise exposed into contact with a heating drum, a recording method is provided. An object of the present invention is to provide a heating and developing apparatus capable of obtaining a high-quality recorded image in which a desired density is sufficiently developed without density unevenness in a width direction of a material.

[0011]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In addition, the present invention provides a heating element
After the imagewise exposure, the photosensitive heat-developable recording material is heated to a predetermined temperature.
Degree T_AA heating drum for heating and developing
The photosensitive heat-developable recording material is brought into contact with the periphery of the drum.
And a heat developing apparatus for performing heat development,
In the width direction of the surface of the heating drum, the photosensitive heat development
Provided corresponding to the area through which the recording material can pass,
Temperature T of the passage area on the drum surface₁The first to detect
A sensor, in the width direction of the heating drum surface,
For areas where the photothermographic material does not always pass
The temperature of the non-passing area of the heating drum surface provided
T _TwoA second sensor for detecting the
Known temperature T₁Is the set temperature T_ACrosses and before
The detection temperature T of the second sensor_TwoIs a predetermined upper limit temperature T
_B(T_B> T_A) If at least one of
While the power supply to the heating element is stopped,
A control unit for energizing the heating element between the outside
There is provided a heating and developing apparatus characterized by the above-mentioned.

Here, the photosensitive heat-developable recording material has a support formed in a sheet shape and an image forming layer provided on the support, wherein the image forming layer comprises 50% of a binder. or it is composed of latex, and a layer containing a reducing agent of organic silver salt and organic silver salts, the upper limit temperature T _B is preferably at the set temperature T _a from 1 to 5 ° C. higher temperatures.

Further, the photosensitive heat-developable recording material has a support formed in a sheet shape, and a light-sensitive heat-sensitive recording layer provided on the support. In addition to the electron-donating colorless dye encapsulated in the microcapsules and, in addition to the thermoresponsive microcapsules, a compound having an electron acceptor and a polymerizable vinyl monomer in the same molecule, and a photopolymerization initiator. Layer, or a layer containing an electron-donating colorless dye encapsulated in a thermoresponsive microcapsule, and, in addition to the thermoresponsive microcapsule, an electron accepting compound, a polymerizable vinyl monomer, and a photopolymerization initiator , and the upper limit temperature T _B is preferably at the set temperature T _a from 1 to 5 ° C. higher temperatures.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a heat developing apparatus of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.

FIG. 1 is a schematic view showing an example of an image recording apparatus to which the heat developing apparatus of the present invention is applied. The image recording device 10 shown in FIG. 1 is a device that is preferably used as a so-called medical imager that creates a print that reproduces an image measured by a medical measuring device such as CT or MRI as a visible image. A light beam L modulated by using a photosensitive heat-developable recording material A (hereinafter, referred to as a recording material A) having a transparent film as a support and modulated according to image data supplied from an image data supply source R such as MRI. By
After the latent image is recorded by imagewise exposing the recording material A by scanning exposure, the exposed recording material A is heated and developed to form a color, and is output as a hard copy on which an image is formed.

As one of the photothermographic recording materials suitably used in the recording apparatus 10 of the present invention, 50% or more of a binder is composed of latex on one surface of a support,
A light- and heat-sensitive recording material (hereinafter, referred to as a first recording material) having an image forming layer containing an organic silver salt and a reducing agent for the organic silver salt is exemplified. In the first recording material, a photocatalyst such as photosensitive silver halide forms a latent image nucleus when exposed to light, and when heated, the silver of the organic silver salt ionized by the action of the reducing agent is formed. Move to combine with the photosensitive silver halide to form crystalline silver, forming an image,
It is a negative photosensitive material. The first recording material is described in detail in Japanese Patent Application No. Hei 9-185724 by the present applicant.

The organic silver salt contained in the image forming layer of the first recording material is relatively stable to light, but is exposed to an exposed photocatalyst (such as a latent image of photosensitive silver halide) and a reducing agent. A silver salt that forms a silver image when heated to 80 ° C. or higher in the presence of, and may be desalted as necessary. Such organic silver salts include a silver salt of an organic acid, preferably a silver salt of a long-chain fatty carboxylic acid having 10 to 30 carbon atoms, and a complex stability constant having a ligand of 4.0 to 10.0. Complexes of organic or inorganic silver salts having, for example, silver behenate, silver arachidate, silver stearate, silver oleate, silver laurate, silver caproate, silver myristate, silver palmitate, maleate Silver acid, silver fumarate and the like are exemplified.

Further, as the organic silver salt, a silver salt of a compound containing a mercapto group or a thione group and a derivative thereof can be preferably used, and specifically, 3-mercapto-4-phenyl-1,2,3 Thioglycolic acid such as 2,4-triazole, 2-mercaptobenzimidazole, dithiocarboxylic acid such as dithioacetic acid, thioamide, 5-carboxyl-1-methyl-2-phenyl-4-thiopyridine, mercaptotriazine, 2-mercaptobenzoxazole And the like.

As the shape of such an organic silver salt, a needle-like crystal having a short axis and a long axis is preferable, and specifically, a short axis of 0.01 μm to 0.20 μm and a long axis of 0.10 μm to 5.0 μm.
0 μm is more preferred. Further, the organic silver salt is preferably monodispersed. Specifically, the standard deviation of the length of each of the short axis and the long axis is divided by the short axis and the long axis to be 100.
The fraction is preferably 100% or less.

Such an organic silver salt is used to obtain polyacrylic acid,
It is preferable to use a known dispersant such as polyvinyl alcohol and polyvinylpyrrolidone to obtain a solid fine particle dispersion. The dispersion of the organic silver salt into solid fine particles may be performed by a known mechanical fine particle dispersion method using a ball mill, a vibration ball mill, or the like in the presence of a dispersant. In addition to the mechanical dispersion method, the pH may be controlled so that the particles are roughly dispersed in the solvent, and then the pH is changed in the presence of a dispersing agent to form fine particles.

The amount of the organic silver salt is 0.1 to 5 g / silver.
l is preferable, and more preferably 1 to 3 g / l.

The reducing agent for reducing such an organic silver salt is as follows:
Any substance that can reduce silver ions to metallic silver can be used, and is preferably an organic substance, such as organic silver disclosed in JP-A-6-3793 and US Pat. No. 5,464,738. Various known reducing agents used for light- and heat-sensitive recording materials using salts can be used. Specifically, bis (2-hydroxy-3-t-butyl-5-methylphenyl) methane, 2,2-bis (4-hydroxy-3-methylphenyl) propane, 4,4-ethylidene-bis (2 -T-butyl-6-methylphenol), 1,1-
Bis (2-hydroxy-3,5-dimethylphenyl)-
Bisphenols such as 3,5,5-trimethylhexane, chromanol, and hindered phenol reducing agents are suitably excited.

The reducing agent may be added by a method such as a solution, a powder, and a dispersion of solid fine particles. The amount of the reducing agent is preferably about 5 to 50 mol% based on 1 mol of silver on the surface having the image forming layer. The reducing agent is basically added to the image forming layer,
Another layer on the side having the image forming layer may be used, and in this case, it is preferable to use a relatively large amount of 10 to 50 mol% with respect to 1 mol of silver. Further, the reducing agent may be a so-called precursor which is derivatized so as to have a function effectively only during development.

The image forming layer of the first recording material contains a substance which becomes a photocatalyst upon exposure, for example, photosensitive silver halide (hereinafter, referred to as silver halide). The halogen composition of the silver halide is not limited, and may be any of silver chloride, silver chlorobromide, silver bromide, silver iodobromide, silver iodochlorobromide, and silver iodide. And silver iodobromide are preferably used. The silver halide particle diameter of the recording material used in the present invention is 0.20 μm or less. Further, in order to suppress cloudiness after image formation, the particle diameter is set at 0.2.
It is preferably 0 μm or less, particularly preferably cubic grains and tabular grains.

The silver halide grains include rhodium, rhenium, ruthenium, osnium, iridium, cobalt,
It is preferable that at least one complex of a metal selected from mercury or iron is contained in an amount of about 1 nmol to 10 mmol per 1 mol of silver. The silver halide grains are preferably chemically sensitized by a known method such as a sulfur sensitization method or a selenium sensitization method.

The amount of the silver halide used is preferably 0.01 mol to 0.5 mol per 1 mol of the organic silver salt.

In the first recording material, the image-forming layer having such a composition is prepared by dispersing a latex obtained by dispersing a water-insoluble hydrophobic polymer as fine particles in a water-soluble dispersion medium in an amount of 50 wt. % Or more. Alternatively, if necessary, other layers may have the same configuration. For such latex, see "Synthetic Resin Emulsion (edited by Tadashi Okuda and Hiroshi Inagaki, published by Kobunshi Kankokai (1
978))), “Applications of Synthetic Latex (Takaaki Sugimura, Yasuo Kataoka, Soichi Suzuki, Keiji Kasahara, edited by Polymer Publishing Association (1993))”, “Chemistry of Synthetic Latex (Souichi Muroi, Polymer Publishing Association) Issuance (1970))).

Examples of such latex polymers include acrylic resins, vinyl acetate resins, polyester resins, polyurethane resins, rubber resins, vinyl chloride resins,
Examples include vinylidene chloride resin and polyolefin resin. The molecular weight of the polymer is 5000 to 100000 in number average molecular weight
0, preferably about 10,000 to 100,000. If the molecular weight is too small, the mechanical strength of the photosensitive layer is insufficient,
If the size is too large, the film-forming property is poor, which is not preferable.

Specific examples of such a polymer include methyl methacrylate / ethyl acrylate / methacrylic acid copolymer, methyl methacrylate / 2-ethylhexyl acrylate / styrene / acrylic acid copolymer,
Styrene / butadiene / acrylic acid copolymer, styrene / butadiene / divinylbenzene / methacrylic acid copolymer, methyl methacrylate / vinyl chloride / acrylic acid copolymer and the like are exemplified. In addition, various commercially available polymers can be used, for example, acrylic resin such as Sebian A-4635 manufactured by Daicel Chemical Industries, Ltd., and polyester resin such as FINE manufactured by Dainippon Ink and Chemicals, Inc.
TEX ES650, etc .; HYDRAN AP10, etc., manufactured by Dainippon Ink and Chemicals, Ltd. as a polyurethane resin; LACSTAR 7310K, etc., manufactured by Dainippon Ink and Chemicals as a rubber-based resin;
As vinylidene chloride resin, L manufactured by Asahi Kasei Corporation
502 and the like, and examples of polyolefin resin include Chemipearl S124 manufactured by Mitsui Petrochemical Co., Ltd.
These polymers may be used alone or as a blend of two or more.

The average particle size of the dispersed particles in the latex is from 1 to
The range is preferably 50,000 nm, more preferably about 5 to 1,000 nm. There is no particular limitation on the particle size distribution of the dispersed particles, and a material having a wide particle size distribution or a material having a monodispersed particle size distribution may be used. Minimum film formation temperature of latex (MF
T) is −30 ° C. to 90 ° C., more preferably 0 ° C. to 70 ° C.
Is preferred.

As described above, in the image forming layer of the first recording material, it is preferable that 50% by weight or more of the total binder is latex, and that 70% by weight or more is latex. If necessary, a hydrophilic polymer such as gelatin, polyvinyl alcohol, methylcellulose, hydroxypropylcellulose, carboxymethylcellulose, or hydroxypropylmethylcellulose may be added to the image forming layer in a range of 50% by weight or less of the total binder. good. Further, the dispersed particles (polymer) of the latex are 2
It is preferable that the equilibrium water content at 5 ° C. and 60% RH is 2 wt% or less, more preferably 1 wt% or less.

Such a first recording material may have various layers in addition to the above-described image forming layer. For example, a surface protective layer, an antihalation layer, a back (coat) layer formed on the surface opposite to the image forming layer of the support, and a layer formed on the same surface as the back layer for the purpose of protecting the image forming layer and preventing adhesion. Backside resistive heating lay
er), an antistatic or conductive layer, a vapor-deposited metal layer, and the like.

The image-forming layer of the first recording material or another layer on the same side as the image-forming layer may contain, in addition to these essential components, a color tone agent, a sensitizing dye, an antifoggant, Agents, stabilizer precursors, benzoic acids for the purpose of increasing sensitivity and preventing fogging, mercapto compounds and sisulfide compounds for the purpose of suppressing or accelerating development, improving spectral sensitization efficiency, and improving storage stability before and after development Known additives contained in recording materials, such as thione compounds, dyes and pigments for the purpose of improving color tone, preventing irradiation, plasticizers, lubricants, ultra-high contrast agents, high-contrast accelerators, hardeners, etc. May be contained.

As another example of a suitable recording material A used in the present invention, the following recording materials are exemplified. This photosensitive heat-developed (thermochromic) recording material (hereinafter referred to as a second recording material) is a recording material in which a photosensitive and thermosensitive (thermochromic) image forming layer is provided on a support. A compound having an electron-accepting colorless dye encapsulated in a thermoresponsive microcapsule, a compound having an electron acceptor and a polymerizable vinyl monomer in the same molecule in addition to the thermoresponsive microcapsule, and a photopolymerization initiator The recording material contains: Further, as another photosensitive / thermosensitive recording material (hereinafter, referred to as a third recording material), a recording material in which a photosensitive / thermosensitive (thermochromic) image forming layer is provided on a support, wherein the image forming layer is It is a recording material containing an electron-donating colorless dye encapsulated in heat-responsive microcapsules, and an electron-accepting compound, a polymerizable vinyl monomer, and a photopolymerization initiator in addition to the heat-responsive microcapsules.

The second and third recording materials cure the composition (hereinafter referred to as a photocurable composition) outside the thermoresponsive microcapsules by exposure to light, and are fixed. As a result, the compound having mobility (not immobilized) having the electron accepting portion and the polymerizable vinyl monomer portion or the electron accepting compound moves in the image forming layer, and the electron donating property in the microcapsule is changed. Is a recording material that forms an image by developing a colorless dye of the formula (1). Both recording materials are disclosed in Japanese Patent Application No. 8-3337 by the present applicant.
No. 24 describes this in detail.

The compound having an electron-accepting portion and a polymerizable vinyl monomer portion in the same molecule, which is used in the photocurable composition of the second recording material, refers to an electron-accepting group and a vinyl group in one molecule. Is a compound containing Specifically, styrenesulfonylaminosalicylic acid, vinylbenzyloxyphthalic acid, zinc β- (meth) acryloxyethoxysalicylate, vinyloxyethyloxybenzoic acid, β- (meth) ataacryloxyethylorselinate, β- ( (Meth) acryloxyethoxyphenol, β- (meth) acryloxyethyl-β-resorcinate, hydroxystyrenesulfonic acid-N-ethylamide, β- (meth) acryloxypropyl-p-hydroxybenzoate,
(Meth) acryloxymethylphenol, (meth) acrylamidopropanesulfonic acid, γ-styrenesulfonyloxy-β- (meth) acryloxypropanecarboxylic acid, and the like, and a metal salt thereof, for example, a zinc salt can be preferably used.

The above compound can be suitably used also as a polymerizable vinyl monomer of the photocurable composition of the third recording material. In addition, as the polymerizable vinyl monomer used in the third recording material, various monomers having at least one vinyl group in a molecule can be used.
For example, (meth) acrylic acid and its esters,
(Meth) acrylamides; maleic anhydride, maleic esters; itaconic acid, itaconic esters; styrenes; vinyl ethers and esters; N-vinyl heterocycles; allyl ethers and esters. In particular, a monomer having a plurality of vinyl groups in the molecule is preferable. For example, (meth) acrylates of polyhydric alcohols, polyhydric phenols, (meth) acrylates of bisphenols, and (meth) acrylate-terminated epoxy There are resins and (meth) acrylate-terminated polyesters. Specifically, ethylene glycol diacrylate, ethylene glycol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hydroxypentaacrylate, hexanediol-1,5-dimethacrylate,
Examples thereof include diethylene glycol dimethacrylate. These monomers have a molecular weight of about 100 to about 500.
Those having about 0 are preferably used.

The photopolymerization initiator used in the second and third recording materials is a compound capable of initiating the photopolymerization of the vinyl monomer, and is preferably used in combination with a green, red to infrared absorbing dye. In addition, it is said that it has sensitivity in this wavelength region and generates radicals upon irradiation with light (Japanese Patent Laid-Open No.
No. 143044) Organic borate salt compounds, more preferably organic borate salts of cationic dyes. The organic borate generates a radical in response to the irradiated laser beam, and the radical initiates the polymerization of the vinyl monomer portion.

As the organic borate salt, a compound represented by the following general formula (1) is used.

Embedded image

In the above general formula (1), M is
Li metal atom, quaternary ammonium, pyridinium, quino
Linium, diazonium, morpholinium, tetrazoli
, Acridinium, phosphonium, sulfonium,
Oxosulfonium, sulfur, oxygen, carbon, halogeniu
, Cu, Ag, Hg, Pd, Fe, Co, Sn, M
cation selected from o, Cr, Ni, As, Se
N is an integer of 1 to 6, R ¹, R^Two, R^ThreeAnd R^Four
Each represents a halogen atom, a substituted or unsubstituted alkyl
Group, substituted or unsubstituted alkenyl group, substituted or unsubstituted
Substituted alkynyl group, alicyclic group, substituted or unsubstituted ant
Alkenyl group, substituted or unsubstituted alkaryl group,
Is an unsubstituted aryloxyl group, a substituted or unsubstituted
Alkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted
Represents a substituted silyl group. Where R¹, R^Two, R^ThreeAnd
And R^FourMay be the same or different from each other, and these
Of these, two or more groups may be bonded to form a cyclic structure.

In the above formula (1), examples of the borate anion include tetraethyl borate, triisobutyl methyl borate, di-n-butyl-di-t-butyl borate, tetraphenyl borate, tetra-p-chlorophenyl borate, and tri-borate. m-chlorophenyl-n-hexyl borate, triphenylethyl borate, trimethylbutyl borate, tolyl isopropyl borate,
Triphenylbenzyl borate, tetraphenyl borate, tetrabenzyl borate, triphenylphenethyl borate, triphenyl-p-chlorobenzyl borate, triphenylethenituburiborate, di (α-nephthyl) -dipropyl borate, triphenylsilyl triphenyl Examples thereof include borate, tritolylsilylphenyl borate, and tri-n-butyl (dimethylphenylsilyl) borate.

The following is an example of the organic borate salt represented by the general formula (1).

Embedded image

In order to increase the light absorption efficiency of the recording light L or the like,
The organic borate salt represented by the general formula (1) is preferably used as a spectral sensitizing dye in combination with green to red and infrared absorbing dyes. Particularly, the maximum absorption wavelength is 500 to 1
Organic cationic dyes having a wavelength range of 100 nm are preferably used, and specifically, cationic methine dyes,
Examples include a cationic carbonium dye, a cationic quinone imine dye, a cationic indoline dye, and a cationic styryl dye. More specifically, as the cationic methine dye, polymethine dye, cyanine dye, azomethine dye, more preferably cyanine, carbocyanine, dicarbocyanine, tricarbocyanine, hemicyanine, etc., as a cationic carbonium dye , A triarylmethane dye, a xanthene dye, an aridudine dye, more preferably rhodamine, etc., and as the cationic quinone imine dye, a dye selected from azine dyes, oxazine dyes, thiazine dyes, quinoline dyes, thiazole dyes, These can be used alone or in combination of two or more.

As the photopolymerization initiator, more preferably,
An organic borate salt of a cationic dye represented by the following general formula (2) is used.

[0045]

Embedded image

In the above formula (2), D ⁺ represents a cationic dye, and R ¹ , R ² , R ³ and R ⁴ are a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl. Group, substituted or unsubstituted aralkyl group, substituted or unsubstituted alkaryl group, substituted or unsubstituted alkenyl group, substituted or unsubstituted alkynyl group, substituted or unsubstituted aryloxyl group, substituted or unsubstituted allylic group It is a group selected from a click group, a substituted or unsubstituted heterocyclic group, a substituted or unsubstituted allyl group, a substituted or unsubstituted silyl group, and an alicyclic group. Also,
R ¹ , R ² , R ³ and R ⁴ may be the same or different from each other, and two or more of these groups may be bonded to form a cyclic structure.

In the above general formula (2), the cationic dye represented by D ⁺ acts as a spectral sensitizing dye, and has a wavelength region of 500 nm or more, especially 550 nm to 550 nm.
An organic cationic dye having an absorption peak in a wavelength region of 1100 nm is preferably exemplified. Specifically, as such an organic cationic dye, those exemplified for the compound of the general formula (1) can be suitably used. Further, as the borate anion, the same ones as in the general formula (1) are preferably exemplified.

An example of the organic borate salt of the cationic dye represented by the general formula (2) is shown below.

Embedded image

[0049]

Embedded image

The content of these photopolymerization initiators is preferably 0.01% by weight to 20% by weight based on the total weight of the photocurable composition (outside of the thermoresponsive microcapsules).

In both recording materials, 2-phenyl-4,6-bis (trichloromethyl) -S-triazine and 2- (p-chlorophenyl) -4 were used together with the above-mentioned photopolymerization initiator and spectral sensitizing dye. , 6-Bis (trichloromethyl)-
S-triazine, 2- (p-methoxyphenyl) -4,
6-bis (trichloromethyl) -S-triazine, carbon tetrachloride, carbon tetrabromide, iodoform, p-nitro-α,
A compound having an active halogen group in the molecule, such as α, α-tribromoacetophenone, can be used in combination as an auxiliary. These compounds are preferably added in an amount of 0.01 to 20 mol based on 1 mol of the spectral sensitizing dye (cationic dye).

An electron-accepting compound is added to the photocurable composition of the third recording material. Further, the photocurable composition of the second recording material may also be added with an electron-accepting compound, if necessary, to improve the color density.
Examples of the electron accepting compound include phenol derivatives such as 2,2'-bis (4-hydroxyphenyl) propane, 4-t-butylphenol, and 4-phenylphenol;
Salicylic acid derivatives such as pentadecylsalicylic acid, 3,5-di (α-methylbenzyl) salicylic acid, 3,5-di (tert-octyl) salicylic acid, metal salts of aromatic carboxylic acids, acid clay, bentonite, novolak resins, Metal-treated novolak resins, metal complexes, and the like. These electron accepting compounds are preferably used in an amount of about 5% by weight to about 1000% by weight of the colorless electron donating dye.

The photocurable composition of such a recording material has, in addition to these compounds, a photocrosslinkable composition such as polyvinyl cinnamate, polyvinyl cinnamylidene acetate, and α-phenylmaleimide group. You may add a photocurable composition etc. Further, these photocrosslinkable compositions may be used as photocurable components. Furthermore, in the photocurable composition, in addition to these compounds, if necessary, to prevent thermal and temporal polymerization of the photocurable composition, with the aim of enhancing stability , P-methoxyphenol, hydroquinone, pyrogallol, 2-hydroxybenzophenone, cuprous chloride and the like may be added. These are present in an amount of 0.1% based on the total weight of the photocurable composition.
It is preferable to add about 001% by weight to 5% by weight.

The photocurable composition is emulsified and dispersed and contained in the image forming layer. Solvents used for emulsifying and dispersing the photocurable composition include cottonseed oil, kerosene, aliphatic ketone, aliphatic ester, paraffin, naphthenic oil, alkylated biphenyl, chlorinated paraffin, phosphate esters such as diphenyl phosphate, and acetyl. Citrate esters such as tributyl citrate; benzoic esters such as octyl benzoate; (meth) such as methyl (meth) acrylate
Examples thereof include acrylates, alkyl halides such as methylene chloride and carbon tetrachloride, and methyl isobutyl ketone. Aliphatic esters and alkyl halides are preferred, and those having a solubility in water of 10% by volume or less are more preferred. These solvents are used for the photopolymerizable compound.
It is preferably used in a proportion of from 500 parts by weight to 500 parts by weight.

As the water-soluble polymer that can be used for emulsifying and dispersing the photocurable composition, a compound that is soluble in water at 25 ° C. in an amount of 5% by weight or more is preferable. Derivatives, proteins such as albumin, cellulose derivatives such as methylcellulose, sugar derivatives such as starches (including denatured starch), polyvinyl alcohol, carboxy denatured polyvinyl alcohol, polyacrylamide, saponified vinyl acetate-polyacrylic acid copolymer, Synthetic polymers of polystyrene sulfonate sugars are mentioned, and gelatin and polyvinyl alcohol are particularly preferable.

On the other hand, as the electron-donating colorless dye encapsulated in the microcapsules of the image forming layers of both recording materials, various conventionally known dyes can be used. In particular,
Triphenylmethanephthalide-based compounds such as 3,3-bis (p-dimethylaminophenyl) -6-dimethylaminophthalide, leuco-auramine-based compounds such as N-halophenyl-leuco-auramine, rhodamine-B-anilino Lactams and other rhodamine lactam compounds; 2- (dibenzylamino) fluoran and other fluoran compounds; phenothiazine compounds such as benzoyl leuconmethylene blue; spiropyran compounds such as 3-methyl-spiro-dinaphthopyran; Various compounds can be used, such as a sulfide compound, a totaphenylmethane compound, a triazene compound, and a fluorene compound. When this recording material is a full-color recording material, U.S. Pat. No. 4,900,149 is used as an electron-donating colorless dye for cyan, magenta, and yellow, and U.S. Pat. , 80
0,148, etc., and JP-A-63-53542, etc., for the cyan coloring type.

Microcapsules containing such an electron-donating colorless dye can be obtained by a method known in the art. For example, an interfacial polymerization method disclosed in Japanese Patent Publication No. 42-771, a method by precipitation of a polymer disclosed in U.S. Pat. No. 3,660,304, and a method disclosed in U.S. Pat. No. 3,796,669. Method using the disclosed isocyanate polyol wall material, U.S. Pat.
A method using an isocyanate wall material disclosed in 914,511, a method using a urea formaldehyde-resorcinol-based wall forming material disclosed in U.S. Pat. No. 4,089,802, and the like are disclosed. Especially,
It is preferable to form a polymer film as a microcapsule wall after emulsifying the core substance.

In particular, a microencapsulation method by polymerization of a reactant from the inside of an oil droplet is preferable in that a recording material having a capsule having a uniform particle size and excellent preservability can be obtained within a short time. For example, when polyurethane is used as a capsule wall material, a polyvalent isocyanate such as m-phenylene diisocyanate or 2,6-tolylene diisocyanate and a second substance which reacts therewith to form urethane (capsule wall) (for example, Polyols such as aliphatic or aromatic polyhydric alcohols and polyamines such as ethylenediamine and trimethylenediamine) are mixed in an oily liquid to be encapsulated, emulsified and dispersed in water, and then the temperature is increased. A polymer formation reaction occurs to form microcapsule walls. At this time, an auxiliary solvent having a low boiling point and strong dissolving power can be used in the oily liquid.

The microcapsules can also be prepared using a water-soluble polymer such as a water-soluble anionic polymer, a nonionic polymer and an amphoteric polymer. Arabic gum, alginic acid, sulfated starch,
Sulfated cellulose, (meth) acrylic acid-based (co) polymer, carboxy-modified polyvinyl alcohol and the like, nonionic polymers include polyvinyl alcohol and hydroxyethyl cellulose, and amphoteric compounds include gelatin and the like. , Gelatin, gelatin derivatives and polyvinyl alcohol are preferred. The water-soluble polymer is 0.0
It is used as a 1% to 10% by weight aqueous solution.

In such a thermochromic recording material, the average particle size of the capsule is 20 μm or less, and particularly preferably 5 μm or less from the viewpoint of resolution. On the other hand, if the capsule is too small, the surface area for a certain solid content becomes large, and a large amount of a wall material is required. Therefore, the thickness is preferably 0.1 μm or more. The colorless electron-donating dye may be present in a solution state in the microcapsule, or may be present in a solid state.

The thermochromic recording material may have various layers such as a protective layer and an intermediate layer in addition to the image forming layer. Further, in each layer of the image forming layer, the intermediate layer and the protective layer of the recording material, particularly in the protective layer, a curing agent, particularly, a gelatin hardening agent such as chrome alum or zirconium sulfate used in the production of photographic light-sensitive materials. It is preferable to use the agent in combination. Further, each layer of the thermochromic recording material has a coating aid,
For various purposes such as antistatic, smoothness improvement, emulsification dispersion, adhesion prevention, various surfactants such as ionic surfactants such as saponin and polyethylene oxide may be used.
In addition, various additives such as dyeing agents for preventing irradiation and halation, ultraviolet absorbers, plasticizers, optical brighteners, coating aids, antistatic agents and slipperiness improvers may be added. Good. Further, it is preferable to add a known matting agent such as silica or polystyrene in the protective layer.
Colloidal silica such as Nissan Chemical's Snowtex series may be added to reduce the adhesiveness, and a fluorescent dye or a blue dye as a bluing agent to increase the whiteness of the recording material may be added. Is also good.

The first, second and third recording materials having such characteristic image forming layers are prepared by preparing a coating solution (emulsion) containing the components of each layer by using a solvent, if necessary. It can be produced by applying and drying by a known means. As the solvent, various solvents used for producing the recording material can be used. Specifically, water, alcohols such as ethanol and isopropanol, halogen-based solvents such as ethylene chloride, ketones such as cyclohexanone and methyl ethyl ketone. , Esters such as methyl acetate cellosolve and ethyl acetate, toluene, xylene, etc. are exemplified.If necessary, a plurality of types may be used in combination. Various surfactants such as nonionic, anionic, cationic, and fluorine may be added. As a coating method, known methods such as a blade coater, a rod coater, a knife coater, a roll doctor coater, a reverse roll coater, a transfer roll coater, a gravure coater, a kiss roll coater, and a curtain coater can be used. In addition, the application amount of each paint,
Of course, the amount of adhesion of each layer after drying is adjusted to be a predetermined amount.

The support for these recording materials is not particularly limited, and various materials used in ordinary recording materials can be used. Specifically, polyester films, polyethylene terephthalate films, polyethylene naphthalate films And resin films such as cellulose nitrate film, cellulose ester film, polyvinyl acetal film and polycarbonate film, various metals such as aluminum, zinc and copper, glass and paper.

The recording apparatus 10 in the illustrated example is basically applied with the photosensitive material supply section 12, the width adjustment section 14, the image exposure section 16, and the heating and developing apparatus of the present invention in the order of conveyance of the recording material A. And a discharge tray 80. Although not shown in FIG. 1 in order to simplify the drawing and clarify the configuration, the recording 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 or a band. Are supplied to the recording device 10 and supplied to the recording device 10 one by one. The photosensitive material supply unit 12 (hereinafter, referred to as a supply unit 12) supplies the recording material A from the magazine 20.
Are taken out and supplied to the width shifter 14 located downstream (hereinafter, referred to as downstream) in the transport direction of the recording material A. The loading units 22 and 24 and the suction cups 26 arranged in each loading unit And supply roller pairs 30 and 32 and transport roller pairs 34 and 36 using
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 recording 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 single-wafer means arranged in each loading section includes suckers 26 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 is supplied to the supply roller pairs 30 and 32 disposed in the respective loading sections. Supply. The recording material A supplied to the supply roller pair 30 is supplied to the conveyance guides 38 and 4.
The recording material A supplied to the supply roller pair 32 while being guided by the transport rollers 40 while the guide material 40 is guided by the transport guides 40 and 42. 14.

The width shifter 14 adjusts the position of the recording material A in a direction perpendicular to the conveying direction (hereinafter referred to as the width direction), and thereby the position of the recording material A in the main scanning direction in the downstream recording unit 16. 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. In addition, the width shifter 1
The alignment of the recording material A in No. 4 may be performed by a so-called center resist that performs alignment with reference to the center of the recording material A.

The image exposing section 16 (hereinafter, referred to as the exposing section 16) is a portion where the recording material A is exposed 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 makes the light incident on a predetermined recording position X. A control device 52 and a polygon mirror 5 as an optical deflector
4, an fθ lens 56, and a falling mirror 58. In addition, the exposure unit 46 includes a known light beam scanning device such as a collimator lens or beam expander for shaping the light beam L emitted from the light source, a surface tilt correction optical system, or a mirror for changing the optical path. Various members to be arranged are arranged as needed.

The light source 50 is a laser that emits a light beam L in a narrow band wavelength range according to the spectral sensitivity characteristics of the recording material A, particularly a light source such as a laser diode (LD). Image data from an image data source R such as MRI and CT is sent to the exposure control device 52. The exposure control device 52 performs tone correction (density correction) on the supplied image data, and drives the light source 50 in accordance with the obtained image data, that is, the recorded image, for example, drives the light source 50 by pulse width modulation, and performs the recording image A light beam L that has been pulse width modulated in accordance with is emitted.

In the image recording apparatus of the present invention,
The modulation method in image recording is not limited to the above-described pulse width modulation, and may be pulse number modulation or intensity modulation. In the case of an apparatus using a light beam as a recording unit as shown in the illustrated example, an AOM (acousto-optic modulator),
External modulation using a modulation element such as an EOM (Electric Engineering Modulator) or a spatial modulation element such as a liquid crystal shutter array may be used.

The light beam L emitted from the light source 50 after being subjected to the pulse width modulation as described above is deflected in the main scanning direction by the polygon mirror 54, and is modulated by the fθ lens 56 so as to form an image at the recording position X. Falling mirror 58
As a result, the optical path is changed, and the light enters the recording position X. The recording device 10 in the illustrated example is a device that performs monochrome image recording, 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. R (red), G (green), and B
An exposure unit having three types of light sources that emit light beams having wavelengths corresponding to the spectral sensitivity characteristics of (blue) is used.

On the other hand, the sub-scanning conveyance 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, the light beam L pulse-modulated in accordance with the recorded image is deflected in the main scanning direction, so that the recording material A is two-dimensionally scanned and exposed by the light beam to form a latent image. Is recorded.

The recording material A on which the latent image has been recorded in the exposure section 16 is then transported by the transport roller pairs 64 and 66 and the like, and is transported to the thermal developing section 18. The heat development unit 18 is a part to which the heat development device of the present invention is applied,
The latent image is made visible by heating the recording material A to thereby develop the latent image into a visible image. As shown in FIGS. 1 and 3, a heating drum 68 and an endless belt 7 are provided.
0, the peeling claw 72 (see FIG. 1), and the first sensor 90.
, A second sensor 92, and a control unit 94 (see FIG. 3).

As shown in FIG. 3, the heating drum 68 is a drum having a heating element 69 built therein. The surface of the heating drum 68 is heated and held at a temperature corresponding to the heat development temperature of the recording material A. , And the recording material A is nipped and conveyed together with the endless belt 70. The heating element 69 is not particularly limited as long as it can heat the surface of the heating drum 68 and can perform on / off control, and a heating light source such as a halogen lamp and a heater are preferably exemplified. The heating element 69 in the illustrated example is a rod-shaped halogen lamp,
a. Both ends of the heating element 69 protrude from both ends of the shaft 68a and are fixed to the side plate, and are connected to a power supply 69a.
When turned off, heat generation and heat generation stop are performed.

The heat development time may be adjusted by changing the conveying speed according to the type of the recording material A. For example, when the recording material containing the latex (first recording material) is used as the recording material A, the heat development time is 10 seconds to 90 seconds, and the recording material containing the thermoresponsive microcapsules (the first recording material) is used. When the second recording material and the third recording material are used, the time is about 3 seconds to 60 seconds.

The endless belt 70 has rollers 74a,
It is stretched around four rollers 74b, 74c and 74d and is pressed so as to be wound around the heating drum 68. The peeling claw 72 applies the recording material A to the heating drum 68.
The recording material A is conveyed by the heating drum 68, and the recording material A is lightly contacted with and separated from the heating drum 68.

The heat developing section 18 is not limited to the configuration shown in the drawings, as long as it can perform heat development by bringing at least the recording material A into contact with the periphery of the heating drum 68. Configurations can be employed. For example, instead of the endless belt 70, rollers may be provided in multiple stages along the circumference of the heating drum 68, and the recording material A may be nipped and conveyed between the multiple rollers and the heating drum 68.

Here, as described above, conventionally, a single temperature sensor is provided so as to measure the temperature at the center of the drum. However, the temperature of the drum is controlled by detecting only the center of the drum, despite the non-uniform temperature distribution in which both ends of the drum become hot and the center of the drum becomes cold when the recording material A is carried in. When,
Even if both ends of the drum are sufficiently high, a situation may occur in which the recording material A is further heated, and both ends in the width direction of the recording material A are heated at a temperature equal to or higher than the set temperature, and density unevenness may occur in the width direction of the recorded image. There is a problem that there is.

On the other hand, according to the present invention, a first sensor 90 for detecting the temperature T _{1 of} an area through which the recording material A can pass (hereinafter, referred to as a passing area) in the width direction of the surface of the heating drum 68, 68 A region in the width direction of the surface where the recording material A does not always pass (hereinafter, referred to as a non-passing region)
A second sensor 92 for detecting the temperature T _2, and a control unit 94 for controlling the heating element 69 on the basis of these two detected temperature T ₁ and T ₂ is provided, setting the temperature T ₁ of the passing area temperature T _A Not only (T ₁ ≧ T _A ), but also when the temperature T _{1 in the} passage area is lower than the set temperature T _A (T ₁ <T _A ).
, The temperature T _{2 in} the non-passing region is equal to the predetermined upper limit temperature T
_When the temperature exceeds _B (T ₂ > T _B ), the power supply to the heating element 69 is stopped to stop the heating, thereby preventing an excessive rise in the temperature of the passage area and eliminating the density unevenness in the width direction. This makes it possible to obtain a high-quality recorded image.

That is, as shown in FIG. 3, the heat developing section 18 is provided with a first sensor 90, a second sensor 92, and a control section 94. The first sensor 90 is for detecting the temperature T ₁ in the passage area on the surface of the heating drum 68, and is a section in the passage area on the surface of the heating drum 68, and where the wound endless belt 70 is separated. Are provided so as to correspond to. The second sensor 92 is for detecting the temperature T ₂ of the non-passing region of the heating drum surface 68, but is provided so as to correspond to the non-passing area of the heating drum 68 surface, even in the non-passage region It is preferable to be provided so as to correspond to the vicinity of the passage area, since it is possible to more effectively prevent a high temperature at both ends of the passage area.

The first sensor 90 and the second sensor 92 are not particularly limited as long as they can detect the temperature of the surface of the heating drum 68 by contact or non-contact. Conventional sensors such as thermocouples and thermistors can be used. Various known temperature detecting means can be used. Among them, it is preferable to use a thermocouple because it is compact, has excellent responsiveness, and is inexpensive.

The control unit 94 includes a first sensor 90 and a second sensor 90.
Detection temperature T of sensor 92₁, T_TwoHeating element 6 based on
9 controls on / off of the power supply 69a. Ingredient
Physically, the control unit 94 includes a passage area of the heating drum 68.
Temperature T at which is to be controlled _AIs set, and
Upper limit temperature that the non-passing area of the heating drum 68 should not exceed
Degree T_B(T_B> T_A) Is set. Further, the control unit 9
4 is the detected temperature T of the first sensor₁Is the set temperature T_ALess than
(T₁≤T_A), The power supply 69a of the heating element 69 is turned on.
To generate heat, and the detection temperature T of the first sensor₁Is T_AOver
Eru (T₁> T_A), The power supply 69a of the heating element 69 is turned off.
To stop heat generation in principle,
Detection temperature T of two sensors_TwoIs the predetermined temperature T_BWhile crossing
(T_Two> T _B) Includes the detected temperature T of the first sensor.₁Smiling
Not (so T₁≤T_A), The heating element 69
The power supply 69a is turned off to stop heat generation.

As described above, the control unit 94 includes the set temperature T _A.
And the upper limit temperature T _B is set. The set temperature T _A is not particularly limited as long as it is a temperature that is optimal for thermal development of the recording material A to be used, and may be appropriately determined according to the characteristics of the recording material A and the development time (conveyance speed of the recording material A). Good. For example, when a recording material containing the latex (first recording material) is used as the recording material A, the recording material may have a temperature of 100 ° C to 1 ° C.
When a recording material (second recording material and third recording material) containing the thermoresponsive microcapsules is used at 40 ° C, 85 ° C to 150 ° C is exemplified, and particularly preferably 120 ° C.

Further, as the upper limit temperature T _B , T _B >
The recording material A and the heating drum 68 are not particularly limited as long as they satisfy T _A , that is, T _B = T _A + α (α> 0).
In consideration of the temperature characteristics of the recording material A, the relationship with the set temperature T _A , the developing time (conveying speed of the recording material A), and the like, the temperature immediately before the density unevenness starts to occur in the recording material A (particularly, both ends in the width direction) Just set it. For example, when the above-described first to third recording materials are used, the temperature difference α is preferably set to 1 to 5 ° C, and particularly preferably 2 ° C. If the value of α is too large, the temperature at both ends of the drum becomes too high and the recording material A
Undesirable occurs a possibility that density unevenness occurs, the value of α is too small, since the heat within the drum center portion is not sufficiently heated it is impossible to heat development at a suitable setting temperature T _A to be stopped .

Accordingly, the control section 94 performs on / off control of the heating element 69 as shown in Table 1 below.

Thus, overheating of the non-passage area detected by the second sensor 92 can be effectively prevented. Therefore, the heating drum 68 increases the temperature of both ends of the passage area as the temperature of the non-passage area increases.
It is possible to make the uneven temperature distribution in the width direction of the surface as uniform as possible, prevent the density unevenness of the recorded image, and realize high-quality thermal development.

In such a thermal developing section 18, the recording material A carried in by the carrying roller pair 66 is nipped and carried by the endless belt 70 and the rollers 76 and 78, and is transported between the heating drum 68 and the endless belt 70. The latent image which has been carried in between and is thermally developed by the heating drum 68 while being conveyed in accordance with the rotation of the heating drum 68 becomes a visible image by exposure. Next, 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, and the heating drum 68
And the recording material A, and the recording material A is separated from the heating drum 68.

The recording material A peeled from the heating drum 68 by the peeling claw 72 after the thermal development by the heating drum 68 is completed in this way is transported out of the apparatus, and is converted into a tray as a hard copy from which an image is reproduced. It is discharged to 80.

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

[0091]

Hereinafter, the present invention will be described in more detail with reference to specific examples of the present invention. (Embodiments 1 to 3) In the above-described image recording apparatus 10 of the present invention, when the above-described first recording material is used and the on / off of the heater as the heating element 69 is controlled under the conditions shown in Table 2. , The temperature range ΔT in the width direction of the recording material A
Was examined. Specifically, when the detected temperatures of the first sensor and the second sensor were the temperatures shown in Table 1, the heating of the recording material A was performed by turning the heater on or off. At this time, the temperature distribution in the width direction of the recording material A was measured by a thermocouple thermometer (Anritsu Meter Co., Ltd.), the range [Delta] T - was calculated (= maximum temperature T _H lowest temperature T _L). Table 2 shows the results.

[0092] (Comparative Example 1) except that the control of the heater on / off based on only the detected temperature T ₁ of the first sensor, the same methods and under the same conditions as in Example 2 to measure the temperature distribution,
The range ΔT was calculated. Table 2 shows the results.

(Results) As shown in Examples 1 to 3 in Table 2, when the control of the present invention shown in Table 1 was performed, the range ΔT was significantly reduced to 1 ° C., and the temperature distribution was uniform. It turns out that it becomes. Also, no density unevenness was observed in any of the recording images thermally developed in Examples 1 to 3. On the other hand, as shown in Comparative Example 1 of Table 2, if the detected temperature T ₂ of the second sensor exceeds the upper limit temperature T _B (T ₂
> T _B ), when thermal development is performed with the heater turned on, the range ΔT becomes as large as 2 ° C., and the temperature distribution becomes non-uniform. The recorded image thus obtained showed some density unevenness. Therefore, the effect of the present invention is clear.

[0094]

As described above in detail, according to the present invention, there is provided a heat developing apparatus for performing heat development by bringing a photosensitive heat development recording material imagewise exposed into contact with a heating drum.
Excessive heating of both ends of the heating drum is prevented, and a high-quality recorded image in which a desired density is sufficiently developed without density unevenness in the width direction of the recording material can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic view of an example of an image recording apparatus to which a heat development device of the present invention is applied.

FIG. 2 is a schematic view of an example of an exposure section of the image recording apparatus shown in FIG.

FIG. 3 is a schematic view of an example of a heating drum of the image recording apparatus shown in FIG.

FIG. 4 is a diagram showing a temperature distribution in a width direction of a heating drum surface. (A) shows the state before the recording material is carried in,
(B) shows the state after the recording material has passed.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 (Image) recording device 12 (Recording material) supply part 14 Width adjustment part 16 (Image) exposure part 18 Thermal development part (Heating development apparatus) 20 Magazine 22, 24 Loading part 26, 28 Suction cup 30, 32 Supply roller pair 34 , 36, 44, 60, 62, 64, 66 transport roller pair 38, 40, 42 transport guide 46 exposure unit 48 scanning transport means 50, 82 light source 52 exposure controller 54 polygon mirror 56 fθ lens 58 falling mirror 68 heating drum 68a shaft 69 heating element 69a power supply 70 endless belt 72 peeling claw 74a, 74b, 74c, 74d, 76, 78 roller 80 discharge tray 84 sensor 90 first sensor 92 second sensor 94 control unit A recording material

Claims (3)

[Claims] (1) By energizing a heating element to generate heat,
The photosensitive heat-developable recording material after imagewise exposure is heated to a predetermined set temperature T.
_AAnd a heating drum for heating and developing.
Contacting the photothermographic recording material around the
A heating and developing device for further performing heat development, wherein the photosensitive thermal expression in a width direction of a surface of the heating drum is provided.
Provided corresponding to the area through which the image recording material can pass,
Temperature T of the passage area on the surface of the heating drum₁The first to detect
1) and the photosensitive thermal expression in a width direction of the heating drum surface.
Provided corresponding to the area where the image recording material does not always pass,
Temperature T of the non-passing area on the surface of the heating drum _TwoDetect
A second sensor, and a detected temperature T of the first sensor.₁Is the set temperature T_ATo
Over temperature and the detected temperature T of the second sensor_TwoBut
Predetermined upper limit temperature T_B(T_B> T_A)
While at least one of them is energized,
Is stopped, and the heater is energized during the rest.
A heating and developing device comprising a control unit. 2. The photosensitive heat-developable recording material has a support formed in a sheet shape and an image forming layer provided on the support, wherein the image forming layer is 50% or more of a binder. There is composed of latex, and a layer containing a reducing agent of organic silver salt and organic silver salts, the upper limit temperature T _B is defined in claim 1 wherein a set temperature T 1 to 5 ° C. temperature higher than _a Heat development device. 3. The photosensitive heat-developable recording material has a support formed in a sheet shape and a light-sensitive heat-sensitive recording layer provided on the support. In addition to the electron-donating colorless dye encapsulated in the microcapsules and, in addition to the thermoresponsive microcapsules, a compound having an electron acceptor and a polymerizable vinyl monomer in the same molecule, and a photopolymerization initiator. Or a layer containing an electron-donating colorless dye encapsulated in a thermoresponsive microcapsule, and an electron accepting compound, a polymerizable vinyl monomer, and a photopolymerization initiator, in addition to the thermoresponsive microcapsule. , and the upper limit temperature T _B is heat development apparatus according to claim 1 wherein a 1 to 5 ° C. temperature higher than the set temperature T _a.