JP2000214566A - Thermal developing device and method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress uneven density and to accomplish high-speed thermal developing with high image quality by supplying thermal developing material to a drum at a timing that the position of the leading end of the thermal developing material may be shifted on the drum in the drum rotating direction between the thermal developing materials which are continuously heated by the drum. SOLUTION: The time TR for rotating the drum once and the shortest interval time Tmin for supplying the leading end of the film F to the drum are set so as to satisfy the following expression: Tmin≠N×TR(provided that N denotes an optional natural number). That is, by supplying the film F to the drum by a pair of supply rollers at the timing so that the position of the leading end of the film F may be shifted on the drum in the rotating direction of the drum among the continuously supplied films F, the films F are prevented from being continuously held at the same position on the drum. The film F to be heated at first is held at the position P1, and the film F to be heated next is held at a position P2 shifted from the position P1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat development apparatus and a heat development method for supplying a heat development material onto an outer peripheral surface of a drum and heating the heat development material to perform heat development.

[0002]

2. Description of the Related Art By continuously supplying a sheet-like heat developing material to an outer peripheral surface of a heated drum, a thermal reaction occurs in the heat developing material, whereby an image formed as a latent image can be visualized. A heat developing device capable of forming a target image has been developed (see Japanese Patent Application Laid-Open No. 10-500977).
According to such a thermal developing device, a sheet-like thermal developing material is
It is supplied to the outer peripheral surface of the drum rotating at a constant rotation speed, and after the drum rotates by a predetermined rotation angle while holding the thermal developing material, the heated thermal developing material is peeled off from the outer peripheral surface of the drum, and at the same time, a new one is obtained. Since the thermal developing material is supplied to the outer peripheral surface of the drum, it is possible to efficiently heat the sheet-like thermal developing material.

[0003]

In such a heat developing apparatus, the time TR during which the drum makes one rotation is equal to the time interval T during which the leading end of the heat developing material is supplied to the drum. Therefore, the heat developing material continuously heated by the heat treatment can be developed under the same conditions, and a mechanism for chucking the heat developing material can be provided on the drum, which is considered to be preferable.

However, it has been found that, in such a case, after a large number of thermal developing materials are thermally developed, density unevenness occurs at the front end and the rear end of the developed thermal developing material in the drum rotation direction.

[0005] In particular, an apparatus capable of thermally developing a plurality of different sizes of heat-developable materials in the direction of rotation of the drum. It was found that heat development caused unevenness in density at the center of the screen, significantly impairing image quality.

Accordingly, Japanese Patent Application Laid-Open No. 11-102059, filed prior to the application claiming the domestic priority of the present application, discloses a density unevenness at the front end and the rear end when continuously developing a film of a certain size. In order to eliminate the problem, it is described that the interval of feeding the photosensitive material is set to more than 0.6 and less than 0.9 or more than 1.1 and less than 1.9.

However, Japanese Patent Application Laid-Open No. H11-102059 discloses
If the time interval for feeding the photosensitive material is 30.7 seconds or 49.9 seconds as in the embodiment described in the above item, there is no problem.
If min is to be shortened to 27 seconds or less, simply doing so cannot prevent the density unevenness from causing a problem.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to suppress the occurrence of such density unevenness and enable high-speed, high-quality thermal development.

[0009]

The present inventors have made intensive studies on the causes of such density unevenness, and as a result, have found the following, and made the present invention. The means for solving the above-mentioned problems are shown below.

(Claim 1) A heat developing material on an outer peripheral surface is heated while rotating at a constant rotation speed.
A drum having an elastic layer of 1 mm or more and a metal supporting member for directly or indirectly supporting the elastic layer, a plurality of rotatable rollers biased by the drum, and a sheet on an outer peripheral surface of the drum; Supply means for supplying the heat-developable material in the form of a solid, and heating the heat-developable material supplied by the supply means while holding the heat-developable material on the outer peripheral surface of the drum by the plurality of rollers. In the thermal developing device for developing, the elastic layer has a thickness of 2 mm or less, a thermal conductivity of 0.4 (W / m / K) or more, and the supply unit includes:
At least between the heat developing materials that are continuously heated by the drum, at a timing at which the position on the drum at which the tip of the heat developing material is supplied shifts in the rotation direction of the drum, the heat developing material is removed. A thermal developing device, wherein the thermal developing device is supplied to the drum.

(Explanation of Claim 1) The thermal developing materials which are continuously heated by the drum, that is, the thermal developing materials supplied at the shortest time interval Tmin, have the positions on the supplied drum in the rotational direction. Therefore, the position at which the front end of the thermal developing material is held is changed, so that only a part of the outer peripheral surface of the drum is not cooled, and the temperature of the entire outer peripheral surface is equalized. Can be
As a result, the effect of suppressing the occurrence of density unevenness and improving the image quality of the thermally developed heat-developable material is described in, for example, JP-A-11-1
As described in Japanese Patent No. 02059, when a heat developing material is guided by urging a guide belt against a metal drum, it is simply obtained. However, when a plurality of guide rollers are urged on the drum to guide the heat development material, a metal support member is provided to increase the rigidity and facilitate processing accuracy, and the heat development material is applied to the drum surface. An elastic layer is provided to improve the adhesion, but if this elastic layer is provided, the density unevenness tends to increase due to the temperature unevenness caused by only one sheet of the heat developing material, and the above-described effect cannot be simply obtained. To But,
When the elastic layer has a thickness of 2 mm or less, and has a thermal conductivity of 0.4 (W / m /
K) or more, it is possible to suppress the temperature non-uniformity caused by only one sheet of the heat-developable material and obtain the above-described effect.
In this case, the minimum time interval Tmin satisfies the following expression 12 with respect to the time TR during which the drum makes one rotation and an arbitrary natural number N. Formula 12: Tmin ≠ N × TR

(Claim 2) The thermal developing material on the outer peripheral surface is heated while rotating at a constant rotational speed, and the thickness of the surface is 0.1 mm.
A drum having an elastic layer of 1 mm or more and a metal supporting member for directly or indirectly supporting the elastic layer, a plurality of rotatable rollers biased by the drum, and a sheet on the outer peripheral surface of the drum; Supply means for supplying a heat-developable material in the form of a roller, and heating the heat-developable material supplied by the supply means while holding the heat-developable material on the outer peripheral surface of the drum by the plurality of rollers. In the thermal developing device for developing, the elastic layer has a thickness of 2 mm or less, a thermal conductivity of 0.4 (W / m / K) or more, and the time for one rotation of the drum is TR, and the n-th supply is performed. Assuming that a time interval between the time at which the tip of the heat developing material is supplied to the drum and the time at which the tip of the (n + 1) th heat developing material is supplied to the drum is T (n), an arbitrary natural number N And the following equations 3 to 5 Thermal development apparatus abundance of natural number n that satisfies is equal to or less than 50%. Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1)

(Description of Claim 2) The time when the drum makes one rotation is TR, the time at which the leading edge of the n-th supplied thermal developing material is supplied to the drum, and the leading edge of the n + 1-th thermal developing material. Is assumed to be T (n) with respect to the time at which is supplied to the drum, the natural number n that satisfies all of the above equations 3 to 5 is 50% or more with respect to an arbitrary natural number N. The temperature of the entire outer peripheral surface can be equalized without cooling only a part of the outer peripheral surface of the drum, thereby suppressing the occurrence of density unevenness and the image of the thermally developed heat-developable material. The effect of improving the quality of the toner is simply obtained when the heat developing material is guided by urging the guide belt against the metal drum as described in, for example, JP-A-11-102059. However, when developing a heat developing material by urging a plurality of guide rollers against the drum, a metal support member is provided to enhance rigidity and facilitate processing accuracy, and the heat developing material is applied to the drum surface. An elastic layer is provided to improve the adhesion, but if this elastic layer is provided, the density unevenness tends to increase due to the temperature unevenness caused by only one sheet of the heat developing material, and the above-described effect cannot be simply obtained. To However, when the elastic layer has a thickness of 2 mm or less and a thermal conductivity of 0.1 mm.
When it is 4 (W / m / K) or more, it is possible to suppress the temperature non-uniformity caused by only one sheet of the heat developing material and obtain the above-described effect.

(Claim 3) A drum for heating the heat developing material on the outer peripheral surface while rotating at a constant rotation speed, and a supply means for supplying a sheet-like heat developing material on the outer peripheral surface of the drum are provided. The supply unit supplies the thermal developing material to the drum at a predetermined transport speed through a predetermined supply path for supplying the thermal developing material. The exposure unit exposes the thermal developing material on the supply path. Means for heating the heat development material supplied by the supply means on the outer peripheral surface of the drum while heating the heat development material.
And the shortest time interval Tmin at which the tip of the thermal development material is supplied to the drum satisfies the following formulas 1 and 2 for an arbitrary natural number N: The exposing means, based on image data formed at random time intervals, exposing the heat developing material at random time intervals when the minimum time interval Tmin or the minimum time interval Tmin is exceeded, whereby the supply means Is the minimum time interval Tmin or the minimum time interval Tmin
When the heat development material is supplied to the drum at random time intervals, the time required for the drum to make one rotation is TR, and the time at which the tip of the nth supplied heat development material is supplied to the drum is The time interval between the time at which the tip of the (n + 1) th thermal developing material is supplied to the drum is T
Assuming that (n), for any natural number N, the following equation 3
A thermal developing apparatus wherein the abundance of natural numbers n that satisfies all of Expressions 5 to 50 is 50% or more. Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1)

(Explanation of claim 3) Since the time interval at which the image data is formed is random, the time interval corresponding to the time interval at which the image data is formed is the shortest time interval Tmin.
In the following cases, the exposure time interval is the shortest time interval Tmin
When the time interval exceeds the minimum time interval Tmin, the exposure time interval becomes a random time interval exceeding the minimum time interval Tmin. Since the supply means supplies the thermal developing material at a predetermined transport speed through a predetermined supply path, the supply means determines that the time interval formed is the shortest time interval Tm.
In the case of less than or equal to in, the time interval to be supplied to the drum satisfies the above formulas 1 and 2 for an arbitrary natural number N, and if it exceeds the shortest time interval Tmin, the thermal developing material is supplied to the drum at random time intervals. Is what you do. By doing so, for any natural number N, for any natural number N, the abundance of the natural number n that satisfies all of the above-mentioned Expressions 3 to 5 becomes 50% or more, and the tip of the heat developing material becomes Substantially lowering the probability of being continuously supplied to the same position on the drum reduces the occurrence of temperature unevenness in the rotational direction on the drum, thereby more effectively suppressing the occurrence of temperature unevenness. On the other hand, when the time interval at which image data is formed is short, heat development is performed at the shortest time interval Tmin, and when the time interval at which image data is formed is long, heat development is performed at that time interval. it can. In addition,
The time interval corresponding to the time interval at which the image data was made is:
For example, the time interval at which the image data is generated may be itself, or the time interval at which the image data is generated + α.

(Claim 4) The supply means changes the transport direction by transporting the thermal developing material carried in from the carry-in direction into the supply path in a carry-out direction different from the carry-in direction. Unit, the transport direction conversion unit,
By carrying out the thermal developing material after carrying out the previous thermal developing material, the thermal developing material is carried out at a time interval with the previously carried out thermal developing material at the minimum time interval Tmin or more. The heat developing material according to claim 3.

(Explanation of claim 4) Even if the supply means is not provided with a timer in order to supply the thermal development material to the drum at a time interval longer than the shortest time interval Tmin, the shortest time interval can be obtained at the transport direction changing section. Tmin can be defined,
In addition, the degree of freedom of the supply path increases. If the degree of freedom of the supply path increases, it is easy to reduce the size of the apparatus, to make it easier for the operator to handle the heat-developable material, and to make the processing when a jam occurs easier. Further, the heat development material may be stopped at the transport direction changing unit and exposed. This makes it possible to perform favorable exposure without unevenness on the heat development material.

(5) A drum for heating the heat developing material on the outer peripheral surface while rotating at a constant rotation speed, a plurality of rotatable rollers urged by the drum, and an outer peripheral surface of the drum. Supply means for supplying a sheet-like heat development material to the drum, and a developing temperature of 80 ° C. or higher while holding the heat development material supplied by the supply means on the outer peripheral surface of the drum by the plurality of rollers. In a heat development device that heats the heat development material by heating for a predetermined heat development time, at least, between the heat development materials supplied to the drum at the time interval of the shortest time interval Tmin, The supply means supplies the thermal developing material to the drum at a timing at which a position at which the tip of the thermal developing material is held shifts in a rotating direction of the drum, and the shortest time interval Tmin is 27 seconds or less, and among the rotatable rollers urged against the drum, at least the roller that first contacts the thermal developing material supplied to the drum is a solid roller. Developing device.

(Explanation of Claim 5) A heat-developable material can be held in close contact with the outer peripheral surface of the drum by means of a rotatable roller urged against the drum. In this case, if the shortest time interval Tmin is 27 seconds or less, and if the roller to which the heat developing material supplied to the drum comes into contact first is a hollow roller, the temperature of this roller is rapidly reduced, A temperature difference occurs between the front end and the rear end of the device, and density unevenness occurs. However, since the roller to which the thermal developing material supplied to the drum first comes into contact is a solid roller, this temperature difference is suppressed, and temperature unevenness due to the synchronization of the rotation cycle of the drum and the supply interval of the film is suppressed. The density unevenness can be favorably suppressed by a synergistic effect with the effect.

(Claim 6) The heat developing material on the outer peripheral surface is heated while rotating at a constant rotation speed, and the thickness of the surface is set at 0.
A drum having an elastic layer of 1 mm or more and a metal supporting member for directly or indirectly supporting the elastic layer, a guide member urged by the drum, and a sheet-like thermal development on the outer peripheral surface of the drum A supply means for supplying a material, wherein the heat development material supplied by the supply means is held on the outer peripheral surface of the drum by the guide member, and a predetermined heat development time at a development temperature of 80 ° C. or more. In the thermal developing device that thermally develops the thermal developing material by heating during the period, at least between the thermal developing materials supplied to the drum at a time interval of the shortest time interval Tmin, the supply unit includes the thermal developing material. The thermal developing material is supplied to the drum at a timing when the position where the leading end of the developing material is held is shifted in the rotation direction of the drum.
min is 27 seconds or less, and the thickness of the elastic layer is 0.1 mm or less.
A thermal developing device having a thickness of not more than 70 mm and a ratio of a thermal conductivity (W / m / K) to a thickness (m) of the elastic layer of not less than 50 (W / m ² / K).

(Explanation of Claim 6) Since the drum has the metal supporting member, the rigidity is high, and the processing accuracy is easily obtained.
In addition, since the elastic layer is provided on the surface, the adhesion between the heat developing material and the drum can be enhanced, and the occurrence of density unevenness due to poor adhesion can be suppressed. However, if the minimum time interval Tmin is 27 seconds or less, the temperature of the surface of the elastic layer tends to be drastically reduced only by thermally developing one thermal developing material. However, when the elastic layer satisfies the conditions of the thickness and the thermal conductivity described above, heat is transmitted well from the metal support member to the surface of the elastic layer, and the temperature decrease of the surface of the elastic layer is suppressed.
In addition, the density unevenness can be satisfactorily suppressed by the synergistic effect of the effect of suppressing the temperature unevenness due to the synchronization of the rotation period of the drum and the film supply interval. The thermal conductivity of the elastic layer is preferably 0.4 (W / m / K) or more from the viewpoint of suppressing temperature unevenness in the elastic layer.

(Claim 7) The heat developing material on the outer peripheral surface is heated while rotating at a constant rotation speed, and the thickness of the surface is set at 0.
A drum having an elastic layer of 1 mm or more and a metal supporting member for directly or indirectly supporting the elastic layer, a guide member urged by the drum, and a sheet-like thermal development on the outer peripheral surface of the drum A supply means for supplying a material, wherein the heat development material supplied by the supply means is held on the outer peripheral surface of the drum by the guide member, and a predetermined heat development time at a development temperature of 80 ° C. or more. In the thermal developing device that thermally develops the thermal developing material by heating during the period, at least between the thermal developing materials supplied to the drum at a time interval of the shortest time interval Tmin, the supply unit includes the thermal developing material. The thermal developing material is supplied to the drum at a timing when the position where the leading end of the developing material is held is shifted in the rotation direction of the drum.
min is 27 seconds or less, and the shortest time interval Tmin
Satisfies said TR and the following formula 8 or formula 9: Equation 8: 19/20 × TR ≧ Tmin ≧ 21/40 × TR Equation 9: 26/20 × TR ≧ Tmin ≧ 21/20 × TR

(Explanation of Claim 7) Since the drum has the metal supporting member, the rigidity is high, and the processing accuracy is easily obtained.
In addition, since the elastic layer is provided on the surface, the adhesion between the heat developing material and the drum can be enhanced, and the occurrence of density unevenness due to poor adhesion can be suppressed. However, if the minimum time interval Tmin is 27 seconds or less, the temperature of the surface of the elastic layer tends to be drastically reduced only by thermally developing one thermal developing material. However, the shortest time interval Tmin is equal to TR and the above equation 8
Or, since Expression 9 is satisfied, the time TR for one rotation of the drum TR
Since the front end of the heat developing material is relatively long with respect to the shortest time interval Tmin supplied to the drum, the temperature of the surface of the elastic layer whose temperature has decreased only by heat developing one sheet of the heat developing material is as follows. It is easy to recover before the thermal developing material is supplied, and the temperature unevenness caused by the synchronization of the rotation period of the drum and the film supply interval is suppressed, and the density unevenness can be suppressed synergistically.

(Claim 8) The shortest time interval Tmin
Satisfies the following equation (10) with the TR. Formula 10: 19/20 × TR ≧ Tmin ≧ 21/40 × TR

(Explanation of Claim 8) Since the time TR during which the drum makes one rotation is longer than the shortest time interval Tmin in which the tip of the heat developing material is supplied to the drum, the temperature unevenness is easily recovered, and the accumulated temperature unevenness is easily recovered. And the unevenness in temperature due to the synchronization of the rotation cycle of the drum and the film supply interval is suppressed, and the unevenness in density can be synergistically suppressed.

(Claim 9) The heat development material on the outer peripheral surface is heated while rotating at a constant rotation speed, and the thickness of the surface is set to 0.1 mm.
A drum having an elastic layer of 1 mm or more and a metal supporting member for directly or indirectly supporting the elastic layer, a guide member urged by the drum, and a sheet-like thermal development on the outer peripheral surface of the drum A supply means for supplying a material, wherein the heat development material supplied by the supply means is held on the outer peripheral surface of the drum by the guide member, and a predetermined heat development time at a development temperature of 80 ° C. or more. In the thermal developing apparatus for thermally developing the thermal developing material by heating during the
The rotation time is defined as TR, and the time interval between the time when the leading edge of the n-th supplied thermal developing material is supplied to the drum and the time when the leading edge of the n + 1-th thermal developing material is supplied to the drum is T. Assuming that (n), for any natural number N, the abundance of natural numbers n that satisfies all of the following Expressions 3 to 5 is 50% or more. Expression 3: (N−1 / 20) × TR ≧ T (N) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1/20) × TR ≦ T (n + 1) Equation 5: ( N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) A temperature sensor and a sheet heater Are provided in close contact with each other, and control heating of the heater according to the temperature detected by the temperature sensor. Wherein the control target temperature of the heater at the timing of supplying the thermal development material onto the drum surface is higher than at other times.

(Explanation of Claim 9) The temperature difference due to the difference between the position of the elastic layer surface and the position of the temperature sensor is larger at the timing when the thermal developing material is heated than at other timings. However, by setting the control target temperature of the heater at the timing when the thermal developing material is heated to a target temperature higher than other timings, the temperature unevenness due to the adverse effect is suppressed, and the rotation period of the drum and the film Since the supply intervals of the films are not likely to be synchronized, the unevenness in temperature due to the synchronization of the rotation cycle of the drum and the supply interval of the film can be suppressed, and the unevenness in density can be suppressed synergistically.

(Claim 10) The heat developing material on the outer peripheral surface is heated while rotating at a constant rotation speed, and the surface is directly or indirectly supporting the elastic layer having a thickness of 0.1 mm or more and the elastic layer. A drum having a metal support member, a guide member urged by the drum, and a supply unit for supplying a sheet-like heat developing material on the outer peripheral surface of the drum, and supplied by the supply unit. A heat developing device that heats the heat developing material at a developing temperature of 80 ° C. or higher for a predetermined heat developing time while holding the heat developing material on the outer peripheral surface of the drum by the guide member; , The time when the drum makes one rotation is TR, the time at which the tip of the n-th supplied thermal developing material is supplied to the drum, and the time at which the leading edge of the n + 1-th thermal developing material is supplied to the drum. Is defined as T (n ), The natural number n that satisfies all of the following Expressions 3 to 5 is 50% or more for an arbitrary natural number N. Expression 3: (N−1 / 20) × TR ≧ T (n) ) Or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1/20) × TR ≦ T (n + 1) Equation 5: (N− (1/20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) The drum on the inner periphery of the metal supporting member is divided in the conveying width direction. A temperature sensor and a planar heater provided in close contact with the metal support member are provided for each of a plurality of regions, and the heat development material of the heater corresponding to a region through which the heat development material does not pass is provided on the drum surface. The heater control target temperature Te11 at the timing of supplying the The heater control target temperature Te12, the heater control target temperature Te21 at the timing of supplying the heat development material of the heater corresponding to the area through which the heat development material passes onto the drum surface, and the other timings. The target control temperature Te22 of the heater is expressed by the following equation 1.
1. A heat developing apparatus, wherein Formula 11: Te11−Te12 <Te21−Te22

(Explanation of Claim 10) Since the probability that the rotation cycle of the drum and the supply interval of the film are synchronized is low, the temperature difference caused by the difference between the surface of the elastic layer and the position of the temperature sensor causes the heat developing material to pass through. In the region where the thermal development material is heated, the timing is greater than the other timings, but in the region where the thermal development material does not pass, there is unevenness in the conveyance width direction where there is not much change. But Equation 11
By satisfying the above condition, the temperature unevenness due to these adverse effects is suppressed, and the probability that the rotation period of the drum and the supply interval of the film are synchronized is low. The density unevenness can be suppressed synergistically.

(11) A ramp process is performed by controlling heating of the heater.
0. The heat developing apparatus according to 0.

(Explanation of Claim 11) Since the heating control of the heater is smoothed by the ramp processing, the occurrence of the temperature unevenness due to the rapid fluctuation of the temperature is suppressed, and the occurrence of the density unevenness due to this is suppressed. Note that the ramp process is a process in which the control target does not change rapidly with time but changes gradually and continuously. As an example of the ramp processing, when the control target temperature changes discontinuously with respect to time, there is a method of changing the control target temperature continuously, but it is not limited thereto.

(Claim 12) At least between the heat development materials supplied to the drum at a time interval of the shortest time interval Tmin, the supply means is configured such that the position where the front end of the heat development material is held, The thermal developing material is supplied to the drum at the timing of shifting in the rotation direction of the drum.
The minimum time interval Tmin at which the tip of the thermal developing material is supplied to the drum satisfies the following expression 1 for an arbitrary natural number N. Heat development equipment.

(Explanation of Claim 12) Since the position on the drum to be supplied is shifted by at least 1/20 of the circumference of the drum between the heat developing materials continuously heated by the drum, In addition, temperature unevenness in the rotation direction on the drum is less likely to occur, so that occurrence of density unevenness can be effectively suppressed.

(Claim 13) The time TR during which the drum makes one rotation and the shortest time interval Tmin at which the tip of the thermal development material is supplied to the drum are expressed by the following equation 2 for an arbitrary natural number N. 13. The heat developing device according to claim 12, wherein the condition is satisfied.

(Explanation of the thirteenth aspect) Even between every other sheet of the heat developing material continuously heated by the drum, the position on the drum to be supplied is shifted at least 1/20 of the circumference of the drum. Since the supply is performed, temperature unevenness in the rotation direction on the drum is more unlikely to occur, so that the occurrence of density unevenness can be more effectively suppressed.

(Claim 14) The supply means is for supplying to the drum thermally developing materials having different lengths along the rotation direction of the drum, and a diameter D of the outer peripheral surface of the drum, The length Lmax in the rotation direction of the heat development material having the maximum length along the rotation direction of the drum among the heat development materials supplied by the supply unit satisfies the following Expression 6. The heat developing device according to claim 1. Formula 6: π × D <2 × Lmax (π is a circular constant) (Explanation of Claim 14) A heat developing material having different lengths along the rotation direction of the drum is supplied to the drum. When the diameter D of the outer peripheral surface of the drum and the length Lmax in the rotational direction of the thermal developing material having the maximum length along the rotational direction of the thermal developing material supplied by the supply unit satisfy the above-described Expression 6. It is possible to suppress unevenness in the density of the heat-developed material that has been heat-developed in the center of the screen, and to improve the image quality.

The means for supplying the heat developing material of different sizes along the rotation direction of the drum to the drum includes, for example, a first case for accommodating a heat developing material of a first size, A second case accommodating a heat development material having a size of 2. The supply means supplies the heat development material to the drum from both the first case and the second case. The first case and the second case can supply the heat developing material having different lengths along the rotation direction of the drum to the drum when the supply unit supplies the heat developing material to the drum. One example is, but not limited to, accommodating a heat development material of a size.

(Claim 15) In the drum, the diameter D of the outer peripheral surface for holding the thermal developing material and the length of the thermal developing material supplied by the supply means along the rotational direction of the drum are equal to each other. The minimum length L in the rotational direction of the heat-developable material
The heat developing device according to any one of claims 1 to 14, wherein min satisfies Expression 7 below. Formula 7: Lm
in <π × D (π is pi)

(Explanation of Claim 15) The curl of the heat developing material is suppressed by increasing the diameter of the drum in accordance with the length of the heat developing material in the rotation direction where the length along the rotation direction of the drum is minimum. In addition, since the heat capacity of the drum can be equal to or more than a predetermined amount, the temperature of the entire drum can be prevented from lowering due to the supply of the heat developing material, and the occurrence of density unevenness can be suppressed.

(Claim 16) The photothermographic material is
16. A sheet-like heat-developable material having a minimum heat-development temperature of 80 [deg.] C. or more containing photosensitive silver halide grains, an organic silver salt and a silver ion reducing agent. Kano thermal development device.

(Claim 17) In the thermal developing apparatus according to any one of claims 1 to 15, the minimum thermal development temperature containing photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent is 8 or less.
A heat development method comprising thermally developing a sheet-like heat development material at 0 ° C. or higher.

(Explanation of Claims 16 and 17) The heat-developable material contains photosensitive silver halide grains, an organic silver salt and a silver ion reducing agent, and has a temperature not lower than the minimum developing temperature of 80 ° C. or higher. In the case where the heat development is performed by the heat developing device, strong density unevenness occurs due to a particularly small temperature difference. However, since the heat developing device according to any one of claims 1 to 15, the heat developing material is continuously disposed at the same position on the outer peripheral surface of the drum. Not only is it not supplied, it suppresses the occurrence of density unevenness and not only obtains a good image, but also has high photosensitivity as a heat-developable material, so that the exposure speed can be increased and image formation with high productivity can be achieved. Can be.

[0043]

[Common explanation] The time required for one rotation of the drum is TR, and n
If the time interval between the time at which the leading end of the thermally developed material supplied to the drum is supplied to the drum and the time at which the leading end of the thermally developed material supplied at the (n + 1) th time is supplied to the drum is T (n), an arbitrary When the natural number n that satisfies all of the following Expressions 3 to 5 with respect to the natural number N is 50% or more, not only the heat development materials supplied to the drum at the time interval of the shortest time interval Tmin, but also Regarding the thermal developing material supplied to the drum at a wider time interval, the leading end of the thermal developing material
Since the probability of being continuously supplied to the same position on the drum is substantially reduced, temperature unevenness in the rotational direction on the drum is less likely to occur, so that temperature unevenness can be more effectively suppressed. .

Incidentally, the existence ratio of the natural number n satisfying the above equation is
When developing M sheets of heat developing materials (M is 100 sheets in the embodiment, but preferably about 100 sheets or more), the leading ends of these heat developing materials are supplied to the drum. The natural number n that satisfies the above equation can be calculated from the time TR at which the drum makes one revolution, but the method is not limited to this. Also,
The abundance of natural numbers n satisfying the above equation is 70% or more (particularly 90% or more) from the viewpoint of suppressing density unevenness more effectively.
It is preferred that Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1)

[0045]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments and examples of the present invention, which are examples of the present invention, will be described. Therefore, the meaning of the terms of the invention and the invention itself should not be construed as being limited by the description of the embodiments and examples of the invention, and it is needless to say that the invention can be appropriately changed / improved. FIG. 1 is a front view of a heat developing apparatus according to an embodiment of the present invention, and FIG.
FIG. 2 is a left side view of the heat developing device. Thermal developing device 1
Reference numeral 00 includes a storage section 110 for the film F, which is a sheet-like heat development material shown in the embodiment, an exposure section 120 for exposing the film F, and a development section 130 for developing the film F. The operation of the heat developing device 100 will be described with reference to FIGS.

In FIG. 2, a film F stored in a case C is stored in the storage section 110 in two stages together with the case C. The film F taken out of the case C by a take-out device (not shown) is drawn out in the direction (horizontal direction) shown by the arrow (1) in the figure. Further, the film F drawn out of the case C
Is transported in a direction (downward) indicated by an arrow (2) in the figure by a transport device 141 composed of a pair of rollers. In addition, by accommodating a film F having a different length in the transport direction on the drum 14 described later for each of the two cases C, the length of the case C in the transport width direction is provided for each of the two cases C. It is needless to say that a plurality of films F having different lengths in the transport direction can be thermally developed on the drum 14 by accommodating different films F.

The film F conveyed below the heat developing device 100 is further conveyed to a conveying direction changing unit 145 below the heat developing device 100.
The transport direction is changed (arrow (3) in FIG. 2 and arrow (4) in FIG. 1), and the process proceeds to an exposure preparation stage.
Further, the film F is obtained from the left side of the heat developing device 100.
In a direction (upward) indicated by an arrow (5) in FIG. 1, the sheet is conveyed by a conveying device 142 including a pair of rollers.
0 to the laser light L in the infrared range of 810 to 780 nm
Irradiated.

The film F receives the laser beam L to form a latent image in a manner described later. Thereafter, the film F is transported in the direction (upward) indicated by the arrow (6) in FIG.
When it reaches the supply roller pair 143, it is supplied to the drum 14 as it is. That is, they are supplied at random timing.

Further, the film F is held on the outer peripheral surface of the drum 14 and rotates at a constant rotation speed together with the drum 14 in a direction indicated by an arrow (7) in FIG. In this state, the film F is heated from the drum,
The latent image is formed as a visible image in a mode described later. Thereafter, when the film F is rotated to the right in FIG. 1 with respect to the drum, the film F is separated and cooled while being conveyed in the direction indicated by the arrow (8) in FIG. It is conveyed in the directions shown in (9) and (10) and can be taken out from the upper part of the thermal developing device 100.

FIG. 3 is a schematic diagram showing the configuration of the exposure unit 120. The exposing unit 120 deflects the laser light L, the intensity of which has been modulated based on the image signal S, by the rotating polygon mirror 113 to perform main scanning on the film F, and also moves the film F in the main scanning direction with respect to the laser light L. The sub-scanning is performed by relatively moving in a direction substantially perpendicular to the above, and a latent image is formed on the film F using the laser beam L.

A more specific configuration will be described below. In FIG. 3, an image signal S which is a digital signal output from an image signal output device 121 is converted into an analog signal by a D / A converter 122 and input to a modulation circuit 123. The modulation circuit 123, based on the analog signal,
The driver 124 of the semiconductor laser 110 is controlled to emit the modulated laser light L from the semiconductor laser 110.

The laser beam L emitted from the semiconductor laser 110 is converged only in the vertical direction by the cylindrical lens 115, and is applied to the rotating polygon mirror 113 rotating in the direction of arrow A in FIG. As incident light. The rotating polygon mirror 113 changes the reflection of the laser beam L in the main scanning direction, and the changed laser beam L
After passing through an fθ lens 114 including a cylindrical lens formed by combining a plurality of lenses, the light is reflected by a mirror 116 provided on the optical path so as to extend in the main scanning direction, and is conveyed in a direction indicated by an arrow Y by a conveying device 142. The main scanning is repeatedly performed in the direction of the arrow X on the operated surface of the film F to be operated (sub-scanned). That is, the laser light L is applied to the entire surface to be scanned on the film F.

The cylindrical lens of the fθ lens 114 transmits the incident laser beam L onto the surface of the film F to be scanned.
The focus is converged only in the sub-scanning direction, and the distance from the fθ lens 114 to the surface to be scanned of the film F is equal to the focal length of the entire fθ lens 114. As described above, in the main exposure section 120, the cylindrical lens 115 and the fθ lens 114 including the cylindrical lens are provided so that the laser beam L is once converged on the rotary polygon mirror 113 only in the sub-scanning direction. Therefore, even if the rotary polygon mirror 113 is tilted or shaken, the scanning position of the laser beam L on the surface to be scanned of the film F is not shifted in the sub-scanning direction.
Scan lines of equal pitch can be formed. The rotary polygon mirror 113 has an advantage that it is superior in scanning stability to other optical polarizers such as a galvanometer mirror. As described above, a latent image based on the image signal S is formed on the film F.

FIGS. 4 to 6 are views showing the structure of the developing unit 130 for heating the film F. More specifically, FIGS.
5 is a perspective view of the developing unit 140, FIG. 5 is a cross-sectional view of the configuration of FIG. 4 taken along the line IV-IV and viewed in the direction of the arrow, and FIG. 6 is a view of the configuration of FIG. FIG.

The developing unit 130 has a drum 14 for heating the film F on the outer peripheral surface while rotating at a constant rotation speed. The developing unit 130 is formed on the film F by maintaining the film F at a predetermined minimum heat development temperature or higher for a predetermined shortest heat development time while holding the film F on the outer peripheral surface of the drum 14. The latent image is formed as a visible image. Here, the minimum thermal development temperature is a minimum temperature at which the latent image formed on the film F starts to be developed by a thermal reaction, and is 115 to 120 ° C. in the present embodiment. On the other hand, the shortest thermal development time is a time required for completing a thermal reaction sufficient to visualize a latent image on the film F by maintaining the thermal development temperature at or above the minimum thermal development temperature.

In the present embodiment, the developing section 130 is incorporated in the thermal developing apparatus 100 together with the exposing section 120, but may be configured separately from the exposing section 120. In such a case, a transport unit that transports the film F from the exposure unit 120 to the development unit 130 is required.

Outside the drum 14, fifteen small-diameter rollers 16 are provided as guide members, and are arranged in parallel with the drum 14 and at equal intervals in the circumferential direction of the drum 14. At both ends of the drum 14, three guide brackets 21 supported by the frame 18 are provided on each side. In addition, by combining the guide brackets 21, opposed C-shaped shapes are formed at both ends of the drum 14.

Each guide bracket 21 has five elongated holes 42 extending in the radial direction. The shafts 40 provided at both ends of the roller 16 protrude from the long holes 42. One end of a coil spring 28 is attached to each of the shafts 40, and the other end of the coil spring 28 is attached near the inner edge of the guide bracket 21. Therefore, each roller 16 is urged to the outer periphery of the drum 14 by a predetermined force based on the urging force of the coil spring 28. The film F is formed on the outer periphery of the drum 14 and the roller 1.
6 and the drum 1
4 is pressed against the outer peripheral surface, whereby the entire surface is uniformly heated.

The shaft 2 coaxially connected to the drum 14
The reference numeral 2 extends outward from the end member 20 of the frame 18 and is rotatably supported by the end member 20 by a shaft bearing 24. A gear (not shown) is formed on a rotating shaft 23 of a micro step motor (not shown) which is arranged below the shaft 22 and attached to the end member 20. On the other hand, a gear is also formed on the shaft 22. The power of the micro step motor is transmitted to the shaft 22 via the chain 25 connecting the two gears, whereby the drum 14 rotates. The transmission of power from the rotating shaft 23 to the shaft 22 may be performed via a gear train instead of a chain.

As shown in FIG. 5, in the present embodiment, the roller 16 is
It is provided over a range of degrees. Two reinforcing members 30 (FIG. 5) connect the end members 20 of the frame 18 and additionally support the end members 20.

A plate-shaped (planar) heater 32 is attached to the entire inner periphery of the drum 14, and the outer periphery of the drum 14 is controlled under the control of a control electronic device 34 shown in FIG. It is designed to be heated. The supply of power to the heater 32 is provided by a slip
This is performed via a ring assembly 35.

In this embodiment, in order to make the structure of the heat developing device 100 compact, the drum 14 is formed in a rotatable cylindrical shape. Is also good. For example, it is conceivable that the film F is placed on a belt conveyor provided with a heater, and the film F is heated while being conveyed by the belt conveyor.

As shown in FIG. 5, the drum 14 includes an aluminum support tube 36 as a metal support member, and a flexible layer (elastic layer) 38 attached to the outside of the support tube 36. ing. The flexible layer 38 may be indirectly attached to the support tube 36. The support tube 36 according to the present embodiment has a length of 45.7.
cm, the wall thickness is 0.64 cm, and the outer diameter is 16 cm. However, within a range satisfying the above equation 7,
The diameter and thickness of the support tube 36 can be arbitrarily changed. For example, the thickness of the metal support tube 36 of the drum 14 is 0.70 cm or more, The effect of accumulating the temperature unevenness in both the width direction is reduced, and in combination with the effect of the present invention that shifts the supply position in the transport direction, the temperature unevenness can be extremely reduced, and the density unevenness can be hardly recognized. If it exceeds 0.0 cm, when the film F is continuously supplied, the temperature unevenness is not large even if the supply position in the transport direction is constant, but not only the cost becomes high but also the heat capacity of the drum 14 becomes large. 2.0 cm or less is preferable because the amount of heat required from the initial state to the heat development state increases and the temperature control becomes difficult.

On the other hand, the uneven thickness of the support tube 36 is as follows.
For example, it is preferable to keep it within 4%. Further, the flexible layer 38 has a sufficiently smooth surface to increase the degree of adhesion to the film F to be heated.
The surface roughness Ra is desirably smaller than 6.3 μm (especially 3.2 μm).

However, the surface roughness Ra of a specific material such as silicon-based
0.3 to prevent sticking to the drum 14
It is preferable that the thickness be at least μm, and it is more desirable that the thickness be at least 2.3 μm. If the surface roughness Ra is not less than 2.3 μm, the gas, especially the volatile material, can be used for the flexible layer 38 and the film F.
It is easy to be discharged from between.

The flexible layer 38 has a sufficient thermal conductivity of 0.3 W / m / K or more, so that the surface temperature of the outer peripheral surface of the drum 14 is maintained uniformly. In the present embodiment, the thermal conductivity of the flexible layer 38 is 0.4 W / m /
K or more.

Since the flexible layer 38 is used, the film 16 can be more securely adhered to the drum 14 by the roller 16 without sacrificing wear resistance. The flexible layer 38 has a Shore A measured with a durometer.
The hardness is preferably 70 or less (especially 60 or less). In the present embodiment, the Shore A hardness measured by a durometer is 55 or less.

It should be noted that certain materials contain an additive for increasing the thermal conductivity and silicon, and such a material has been found to be particularly useful for forming the flexible layer 38. Have been. Although the thermal conductivity of silicon contained in such a material is relatively small, the silicon improves the pressing performance of the film F and the durability (abrasion resistance) to the film F.

On the other hand, in order to improve the processing capacity of development, it is necessary to increase the thermal conductivity. However, the additives in the above-mentioned materials contribute to maintaining the thermal conductivity at a high level. It is. However, in the material forming the flexible layer 38, if the additive amount of the additive is increased, the pressing performance and durability of the silicon are reduced. There is. The silicon-containing material has an advantage that it is easily separated from the film F and is chemically inert.

The thickness of the flexible layer 38 is preferably 0.1 mm or more, and it is also possible to use a thinner flexible layer 38. However, there is a problem that its manufacture becomes difficult. Further, since the drum 14 has the metal supporting member, the rigidity is high, the processing accuracy is easily obtained, and the
Since the elastic layer 38 having a thickness of at least mm is provided on the surface,
The adhesion between the heat developing material and the drum can be improved, and the occurrence of density unevenness due to poor adhesion can be suppressed. And it is more preferable that the thickness of the flexible layer 38 is 0.4 mm or more.

Further, the variation in the thickness of the flexible layer 38 is as follows.
On the surface region, it is preferable that the content is 20% or less (particularly 10% or less). In the present embodiment, it is suppressed to 5% or less. The ratio of the thermal conductivity to the thickness of the flexible layer is 0.0
It is preferable that the number is 2 or more, because the temperature difference between the region where the film F is located and the other region is small, and the density unevenness hardly occurs.

When the thickness of the flexible layer is 2 mm or less, the instability of heating of the heat-developable material due to excessive elastic deformation is prevented, and heat is transmitted from the metal supporting member to the surface of the elastic layer. Preferred from the viewpoint of heatability, especially 0.7 mm
It is preferable that the temperature is equal to or less because the temperature unevenness hardly occurs and the density unevenness hardly occurs.

In the present embodiment, a rotatable roller 16 is used as a guide member. However, other means, such as a small movable belt, can be used. In the present embodiment, an aluminum tube having an outer diameter of 2.18 cm and a wall thickness of 1 mm is used as the roller 16. Since the roller 16 is hollow, the suppression of heat conduction is assisted, whereby the influence of the heat of the roller 16 during development can be eliminated as much as possible.

As described above, the urging force of the coil spring 28 is used to reduce the pressing force of the roller 16 so that the film F adheres more securely to the outer peripheral surface of the drum 14 and receives sufficient heat transfer. Care must be taken when choosing the value, as it is a decision. If the urging force of the coil spring 28 is too small, heat may be unevenly transmitted to the film F, so that image development may be incomplete. If the biasing force is too small, the roller 16
There is a fear that the robot will not hang around. In such a case, when the film F rotates with the drum 14 and the roller 16 is in contact with the film F, the film F
May be damaged by the roller 16.

On the other hand, the urging force of the coil spring 28 needs to be small enough that the roller 16 does not cause any indentation on the film F. In addition, when each coil spring 28 is used for the roller 16 provided around the cylindrical drum 14, the urging force of each coil spring 28 is applied to each roller 16.
Should be determined in consideration of the gravity acting on the surface. For example,
The coil spring 28 biasing the roller 16 located above the drum 14 is more responsive to the weight of the roller 16 than the other coil springs 28 biasing the roller 16 at the bottom of the drum 14. By using a small urging force, substantially the same surface pressure can be applied to the entire film F.

In order to solve or alleviate the above-described problem, in one example, the force applied to the film F by the roller 16 is changed in the width direction 1 of the film F.
The range of 7.2 to 200 g per centimeter (especially,
(In the range of 7.2 to 100 g). In the present embodiment, this force is between 14 and 30 g per centimeter in the width direction of the film F. In addition, by maintaining the force within this range, harmony between the reduction of the indentation and the reduction of the unevenness of the image can be ensured.

The space between adjacent rollers 16 in addition to the force exerted by each roller 16 can be said to be important for high quality image formation on the film F. When the film F is supplied to the drum 14,
The temperature is generally room temperature (approximately 20 ° C.). Therefore, in order to maximize the processing capacity of the developing unit 130,
The film F must be rapidly heated from room temperature to the minimum heat development temperature (115-120 ° C. or higher in this embodiment) required to start development.

However, the base material contained in a certain kind of film F, for example, a plate material based on a polyester film or a plate material based on another thermoplastic (material), There is a risk of thermal expansion and contraction (shrinkage). Therefore, in order to make the dimensional change uniform so that wrinkles (folds) are not formed, the film F
Must be evenly heated when alternating between a state held flat and an unrestrained state. In order to realize this, the plurality of rollers 16 change the area (region) of the film F located between the adjacent rollers 16 when the film F is not restrained between the rollers 16 and the drum 14. Are provided at intervals so as to allow for

However, as described above, in order to conduct heat sufficiently and uniformly to uniformly develop the film F, the roller 16 is held for a predetermined time while the film F is urged against the drum 14. Must.
As a result, the spacing located between adjacent rollers 16 should be selected so that wrinkles are minimized and that the heating of film F occurs quickly and uniformly. is there.

Further, on the outer periphery of the cylindrical drum 14,
The rigidity of the film F itself causes its leading edge to extend tangentially between the rollers 16, but the rollers 16 must be sufficiently close together to suppress this. Such an arrangement is important for holding the film F between the roller 16 and the drum 14.

As shown in FIGS. 4 to 6, fifteen rollers 1
6 are provided over 224 degrees in the rotation direction of the drum 14, and each space is 16 degrees from the center to the center.
Separated by degrees. This configuration has a base thickness of 0.18 if the diameter of the drum 14 is between 8.9 cm and 20.3 cm and the diameter of the roller 16 is 2.18 cm.
mm, such as a polyester film whose film F is relatively hard, and a film F whose film thickness is smaller, such as a polyester film whose base thickness is 0.10 mm. It is what you do.

The heater 32 is provided in close contact with the inner periphery of the drum 14 to heat the outer peripheral surface of the drum 14. As the heater 32 for heating the drum 14, an etched resistive foil heater can be used.

The electronic device 34 for controlling the heater includes the drum 1
4, and the power supplied to the heater 32 can be adjusted according to the temperature information sensed by the temperature sensors S1 and S2. The details of the temperature control will be described later. The heater 32 and the control electronic device 34 can adjust the outer surface temperature of the drum 14 so that the temperature becomes suitable for the development of the specific film F. It goes without saying that a temperature sensor for detecting this temperature is also provided in close contact with the inner periphery of the drum 14. In the present embodiment, the heater 32 and the control electronic device 34 can heat the drum 14 to a temperature of 60C to 160C.

Here, the heater 32 and the control electronic device 3
It is preferable to maintain the temperature of the drum 4 in the width direction of the drum 14 within 2.0 ° C. (in particular, within 1.0 ° C.). In the present embodiment, the temperature is maintained within 0.5 ° C.

The undeveloped film F supplied at a predetermined timing from the supply roller pair 143 is supplied to the developing unit 130 by the heating member 14 and the lowermost roller 16 (ie, the nip 52 shown in FIG. 5). It is supplied into the formed grip. Next, the film F is transferred to the drum 14
Rotate together. At this time, the film F is urged against the drum 14 by the roller 16 and is brought into contact with the outer periphery of the drum 14 for a predetermined time during the rotation.

Since the drum 14 can move at substantially the same speed as the film F to be developed, the possibility that the surface of the film F is scratched (damaged or damaged) is reduced, thereby securing a high quality image. can do. After being transported between the drum 14 and the roller 16, the developed film F is transferred to a nip portion (that is, a nip 50 shown in FIG. 5) formed by the roller 16 and the drum 14 located at the most upstream side. It is guided and pulled out of the developing unit 130.

The developing unit 130 is configured to develop various films F such as a 0.178 mm polyester base layer coated with a photothermographic emulsion containing infrared-sensitive silver halide as described in Examples. Can be. The drum 14 is maintained at a temperature of 115 ° C. to 138 ° C., for example, at 124 ° C.
For about 15 seconds, which is a predetermined time, at a rotational speed such that it is held in contact with its outer peripheral surface. At the predetermined time and the temperature, the film F can be raised to a temperature of 124 ° C.

The thickness and the thermal conductivity of the flexible layer 38 are selected so that the continuous processing of the plurality of films F can be efficiently performed. Of course, these parameters can be varied according to the specific characteristics (properties) of the film F to be developed and according to the desired throughput. For example, the temperature and rotation speed of the drum 14 can be varied, as well as the predetermined time that the film F contacts the drum 14, to develop a film F having different development requirements.

In addition, similarly to the drum 14, the rollers 16
A flexible layer can also be provided. Also, instead of providing the roller 16 with a flexible layer, the drum 14 may be provided with a less flexible outer layer. Further, the drum 14 may be a rotating roller, and a cylindrical drum or a supported flat endless belt may be configured to function as the roller 16.

The heat-developable emulsion layer of the film F is composed of the flexible layer 38
Is preferably in contact with. However, the opposite side of the film F can also be in contact with the flexible layer 38. In addition, it is desirable that the thermally developed emulsion layer of the film F be in contact with the outer peripheral surface of the drum 14. However, the opposite side of the film F also
Further, it can be in contact with the drum 14.

Following the thermal development of the image, the film F is preferably withdrawn from the development station 130 and guided in a direction away from the surface of the drum 14 and then cooled.
It can be guided in the direction of 0A. However, due to the structure for pulling out and guiding the film F, the risk of scratching (damage) is reduced, and the risk of wear on the surface is also reduced. In addition, the developed film F is gradually cooled at first in the cooling device,
Thereafter, it is rapidly cooled.

FIG. 7 is a cross-sectional view of the film F shown in the example, and is a diagram schematically showing a chemical reaction in the film F during exposure. FIG. 8 is a cross-sectional view similar to FIG. 7, schematically showing a chemical reaction in the film F during heating. In the film F, a photosensitive layer mainly composed of polyvinyl butyral is formed on a support (base layer) made of PET, and a protective layer made of cellulose butyrate is further formed thereon. The photosensitive layer contains silver behenate (Beh. Ag), a reducing agent and a toning agent.

When the film F is irradiated with the laser beam L from the exposure unit 120 during the exposure, as shown in FIG.
Silver halide grains are exposed to the area irradiated with the laser beam L, and a latent image is formed. On the other hand, when the film F was heated, as shown in FIG. 8, silver ions (Ag) were converted from silver behenate.
⁺ ) Is released, and the behenic acid releasing silver ions forms a complex with the toning agent. Thereafter, silver ions are diffused, and the reducing agent acts with the exposed silver halide grains as nuclei to form a silver image by a chemical reaction. As described above, the film F contains the photosensitive silver halide particles, the organic silver salt, and the silver ion reducing agent, and is not substantially thermally developed at a temperature of 40 ° C. or lower, and is not substantially developed at a temperature of 80 ° C. or higher. Thermal development is performed at a temperature higher than the temperature.

One problem in the image formation based on the thermal development is that if the sheet-like thermal development material (film F) is not uniformly heated, the thermal development material will have a temperature variation, and the thermal development material will be formed due to this. That is, the density of the image may vary. Therefore, the drum 14
Needs to be heated to a uniform temperature of, for example, about 120 ° C. over the entire circumference.

On the other hand, the sheet-like heat developing material (film F) is maintained at room temperature before being supplied to the drum 14, so that heat development is not performed carelessly. I have. However, the temperature of the heat developing material before being heated by the drum 14 is usually lower by about 90 to 100 ° C. than the temperature of the outer peripheral surface of the drum 14, and the heat developing material is supplied to the drum 14 to cool the drum surface. As a result, the outer peripheral surface of the drum 14 with which the heat developing material comes into contact is cooled, and the temperature in that region is reduced.

Here, if the size of the heat developing material supplied to the drum 14 is constant and the position held on the outer peripheral surface of the drum 14 is also constant, the leading end and the rear end of the heat developing material Except for the above, the outer peripheral surface of the drum 14 is uniformly cooled, so that there is no particular variation in the density of the image located at the center. However, there are cases where it is desired to suppress variations in the density of the images located near the front end and the rear end of the heat developing material and to ensure high image quality. Note that the size used here refers to the length of the heat development material in the rotation direction of the drum 14.

In addition, there is a case where it is desired to supply the heat developing materials of different sizes to the drum 14 in any order. In such a case, at the same holding position on the outer peripheral surface of the drum 14,
For example, when a plurality of small-sized thermal developing materials are supplied, the outer peripheral surface of the drum 14 in contact with the thermal developing material is cooled, and a region where the surface temperature is partially reduced is generated. Thereafter, when a large-size heat-developable material is supplied over an area where the temperature has decreased and an area where the temperature has not decreased, a large change in the image density occurs at the boundary. Becomes Such density changes may degrade the quality of the image.

On the other hand, when the temperature of the outer peripheral surface of the drum 14 is partially reduced, the heated heat developing material is peeled off from the drum 14 and then the temperature of the outer peripheral surface of the drum 14 becomes uniform. It is also conceivable to wait until the temperature becomes and then supply a new heat developing material. However, it takes a relatively long time until the temperature of the outer peripheral surface of the drum 14 becomes uniform, which causes a new problem that the processing time is delayed.

FIG. 9 is a diagram for explaining such a problem. FIG. 9A shows the drum 14 and the films F1, F
2 is an expanded view, in which the vertical axis indicates the position of the drum 14 in the width direction, and the horizontal axis indicates the position of the drum 14 in the rotation direction. FIG. 9B is a diagram illustrating a temperature distribution on the outer peripheral surface of the drum 14, where the vertical axis indicates the temperature and the horizontal axis indicates the position of the drum 14 in the rotation direction. 9 (c) and 9 (d)
Is a diagram showing the density distribution of the image of the film F, wherein the vertical axis represents the density and the horizontal axis represents the position of the drum 14 in the rotation direction. Note that, as shown in FIG. 9, the sizes of the films F1 and F2 are shorter than the circumference of the drum 14.

Here, it is assumed that two or more small-sized films F1 are heated in the same area P1 or P2 of the drum 14. In such a case, the areas P1 and P2 on the outer peripheral surface of the drum 14 are cooled, and as shown in FIG. 9B, lower by about 3 degrees than the other areas, depending on conditions such as the temperature of the film. Might be. From such a state, when the film F1 of the same small size is heated in the same region P1 or P2 of the drum 14, the temperature distribution follows the temperature distribution on the outer peripheral surface of the drum 14 shown in FIG. 9B. Becomes

According to the heat development of the present embodiment, the higher the heating temperature, the higher the density of the image tends to be. Accordingly, as shown in FIG. 9C, the density of the image on the film F1 increases at the positions P1 and P2, that is, near the leading end and the trailing end of the film F1, and decreases at other places. When a main image is not formed near the leading end and the trailing end of the film F1, it is unlikely that the density of the image becomes a problem, but it may be near the leading end and the trailing end. However, there are cases where it is desired to suppress variations in image density.

Further, when two or more small-sized films F1 are heated in the same areas P1 to P2 of the drum 14, and then a large-sized film F2 is heated in the areas P1 to P3 of the drum 14, Its temperature distribution includes
As shown in FIG. 9B, a relatively large change portion (near the position P2) occurs in the central region of the film F2.

As described above, if the film F2 is heated with the portion where the temperature distribution changes, the density of the image greatly changes at the central portion of the film F2 as shown in FIG. 9D. It is difficult to secure a high quality image. In particular, since there is a high possibility that the main image of the observer's attention is located at the center of the film F2, the observer may feel uncomfortable even with a slight change in density.

Therefore, in the present embodiment, variations in image density are reduced in the following manner. FIG. 10 is a diagram for explaining an aspect of reducing the density variation of an image. FIG. 10A is a developed view showing a position for sequentially holding a plurality of films F with respect to the drum 14, the vertical axis indicates the supply order of the films F, and the horizontal axis indicates the rotation direction of the drum 14. Indicates the position.
FIG. 10B is a diagram illustrating a temperature distribution on the outer peripheral surface of the drum 14, where the vertical axis indicates the temperature and the horizontal axis indicates the position of the drum 14 in the rotation direction. FIGS. 10 (c) and 10 (d)
FIG. 4 is a diagram illustrating a density distribution of an image on a film F, where the vertical axis indicates density and the horizontal axis indicates a position of the drum 14 in the rotation direction.

That is, in the case where the film F is continuously heated by the drum 14, if the film F is always held at the same position, the temperature at that position on the outer peripheral surface of the drum 14 decreases, so If it is held, the outer peripheral surface of the drum 14 is cooled substantially uniformly, so that the temperature distribution can be maintained substantially uniform.

It is needless to say that the heat developing materials continuously heated by the drum 14 are the heat developing materials supplied to the drum 14 at the shortest time interval Tmin.

More specifically, the time TR during which the drum 14 makes one rotation and the shortest time interval Tmin, which is the shortest time interval at which the leading end of the film F is supplied to the drum 14, are determined with respect to an arbitrary natural number N. , The following equation 12 is satisfied. Expression 12: Tmin ≠ N × TR That is, the position at which the leading end of the film F is held between at least the continuous films F by the supply roller pair 143 is the drum 1
The film F is supplied to the drum 14 at a timing such that the film F shifts in the rotation direction of the drum 4.
What is necessary is not to keep it in the same position continuously.

More specifically, as shown in FIG. 10A, the film F to be heated first is held from the position P1, and the film F to be heated next is moved to the position P2 shifted from the position P1. , The temperature distribution on the outer peripheral surface of the drum 14 becomes uniform as shown in FIG. Therefore, a small-sized film F1,
Alternatively, regardless of the large-size film F2, it is possible to uniformly heat the entire surface of the film F2, so that the density distribution of the image can be made substantially constant (FIG. 1).
0 (c), see FIG. 10 (d)).

Further, in this embodiment, the drum 1
The time TR in which the film 4 rotates once and the shortest time interval Tmin in which the leading end of the film F is supplied to the drum 14 satisfy the following equation 1 for an arbitrary natural number N.

As a result, the drum 1 supplied between the films F continuously heated by the drum 14 is supplied.
4 is supplied at a position deviated by at least 1/20 of the circumference of the drum, that is, by setting the amount of deviation between continuously supplied films to 360/20 = 18 degrees or more, Temperature distribution on the outer peripheral surface of the drum 14 can be efficiently made uniform, whereby temperature unevenness in the rotation direction on the drum 14 is less likely to occur, and the occurrence of density unevenness in the image can be more effectively suppressed. .

Further, the time TR during which the drum 14 makes one rotation and the shortest time interval Tmin at which the leading end of the film F is supplied to the drum 14 satisfy the following expression 2 for an arbitrary natural number N. It has become.

As a result, the position on the drum 14 to be supplied is shifted by at least 1/20 of the circumference of the drum even between every other film F continuously heated by the drum 14. Therefore, the temperature non-uniformity in the rotation direction on the drum 14 is less likely to occur, and the occurrence of the density non-uniformity is more effectively suppressed.

In particular, the minimum time interval Tmin between the time when the leading edge of the film is supplied to the drum and the time when the leading edge of the next film is supplied to the drum,
It is desirable that the time for one rotation of TR satisfy the following Expressions 13 to 15. Thereby, 21/40 × TR ≦
Tmin, the shortest time interval Tmin is sufficient, and after the thermal development of one film F, the outermost surface of the drum 14 is exposed during the shortest time interval Tmin until the next film F is continuously thermally developed. Can restore the temperature,
Since Tmin ≦ 39/20 × TR, the shortest time interval Tm
Since “in” is sufficiently small, the productivity of thermal development for thermally developing the film F is high. Equation 13: 21/40 × TR ≦ Tmin ≦ 19/20 × TR Equation 14: 21/20 × TR ≦ Tmin ≦ 59/40 × TR Equation 15: 61/40 × TR ≦ Tmin ≦ 39/20 × TR

FIG. 12A shows the position of the film F when the film F is continuously supplied to the drum 14 at the shortest time interval Tmin. As shown in FIG. 12A, since the position where the film F is supplied is regularly shifted, the temperature distribution on the outer peripheral surface of the drum 14 is as shown in FIG.
It becomes flat as shown in FIG. The entire surface can be uniformly heated, and as shown in FIG. 12C, the concentration distribution of the thermally developed film F can be made flat.

Further, the time required for the drum 14 to make one rotation is represented by TR
When a time interval between the time when the leading edge of the n-th supplied film is supplied to the drum and the time when the leading edge of the (n + 1) -th supplied film is supplied to the drum is T (n), an arbitrary natural number With respect to N, the natural number n that satisfies all of the following Expressions 3 to 5 is 50% or more.
It is desirable to do. Thereby, not only between the heat development materials continuously heated by the drum, that is, not only between the heat development materials supplied to the drum at the shortest time interval Tmin, but also at a wider time interval. Also, since the probability that the leading end of the heat developing material is substantially continuously supplied to the same position on the drum becomes low, the temperature unevenness in the rotation direction on the drum hardly occurs. Therefore, the occurrence of temperature unevenness is more effectively suppressed, and the temperature distribution on the outer peripheral surface of the drum 14 is
The uniformity can be efficiently achieved, and the occurrence of density unevenness in the image can be more effectively suppressed. Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) To explain, when n = 1, the film F
The time interval T1 between 1 and the subsequent film F2 is:
Formula (5) is satisfied, the time interval T2 between the film F2 and the subsequent film F3 is satisfied with the formula (6), and the time interval T1 + T2 is satisfied with the formula (7). However, when n = 2, the film F3
And the subsequent time interval T3 between the film F4 and
For example, when 100 sheets of the film F are successively thermally developed such that the equation (6) is not satisfied, the number of sheets satisfying all of the above equations 3 to 5 is 50 for an arbitrary natural number N. If there are 50 sheets that do not satisfy any of the above equations 3 to 5 for an arbitrary natural number N, the existence rate is 50%. As described above, the above-described existence rate can be statistically obtained from the supply timing.

The natural number n that satisfies the above expression is such that when the thermal development processing is performed on M films F (the M images are preferably about 100 or more) successively,
The time at which the leading end of the film F is supplied to the drum 14 is recorded sometime, and from the time TR during which the drum 14 makes one rotation, the natural number n satisfying the above equation can be calculated as a percentage. Not limited. Further, the abundance of the natural number n satisfying the above equation is preferably 70% or more (particularly 90% or more) from the viewpoint of more effectively suppressing density unevenness.

Further, in this embodiment, since the temperature distribution on the outer peripheral surface of the drum 14 can be made substantially constant as described above, not only the lengths of the drums 14 in the rotational direction are the same but also different sizes. Can be heated in any order. More specifically, even after heating a plurality of small-sized films, it is possible to suppress the occurrence of temperature unevenness before and after the rotation direction at the position on the drum 14 where the rear end of the film is located. Thereafter, for example, as shown by a dashed line x in FIG.
It is possible to prevent the density unevenness of the image from occurring in any part, and to improve the image quality.

Next, a mechanism for determining a supply timing for supplying the film F to the drum 14 according to the present embodiment will be described. In FIG. 4, a motor 1 is provided on one roller of the supply roller pair 143 located below the drum 14.
51 are connected. Further, the motor 151 controls the film F sent from the exposure unit 120 at random timing.
Is supplied to the drum 14 as it is. This is the exposure unit 12
Since the time required to convert the image data used for exposure with 0 from the transmitted compressed data format to the exposure data format differs for each image data, the timing at which the image data can be restored is a random timing. Therefore, the film F is sent from the exposure unit 120 at random timing.

In this case, it is better to do the following. A transport direction conversion unit 145 that converts the transport direction of a film provided in a common transport path for a plurality of films F of different sizes from (3) to (4).
During the shortest time interval Tmin from when the film F enters in the transport direction (3) to when the film F exits in the transport direction (4), the next film F is transported by the transport direction converter 14.
It is needless to say that the film F is not overlapped by the transport direction conversion unit 145 so that the film F does not fall within the range (5).
And if the time required to convert from the transmitted compressed data format to the exposure data format exceeds the shortest time interval Tmin, wait until image data can be restored, The film F is supplied to the exposure unit 120 at random timing.

Thus, the probability that an arbitrary natural number N satisfies all of the above-described equations 3 to 5 can be increased without providing a special control device. It is preferable because the transfer direction of the film can be changed, the degree of freedom of the transfer path is high, the apparatus can be downsized, and the jam film can be easily taken out.

When the exposure unit 120 performs exposure while the film F is stopped, it goes without saying that the exposure unit 120 may also serve as the transport direction conversion unit 145.

<Modification 1> Next, a modification of the present embodiment will be described. In the present embodiment, time intervals exceeding the shortest time interval Tmin are controlled to be random.
The supply timing may be adjusted so as to be appropriately driven under the control of the control device 150 and to satisfy all of the above Expressions 3 to 5 for an arbitrary natural number N.

More specifically, the supply roller pair 143 temporarily stops when the film F reaches the supply roller pair 143, and supplies the film F to the drum of the developing unit 130 rotating at a constant rotation speed. Has the function of determining In this case, the supply means includes a supply roller pair 14.
3, the motor 151, and the control device 150. In this case, the rotation of the supply roller pair 143 is stopped for the film F conveyed from the lower conveyance unit 142 (FIG. 1), and the film F is temporarily stopped just before the supply roller pair 143. Here, from the phase of the drum 14 detected by a sensor (not shown), the control device 150 transfers the film F to the drum 14 at a constant time interval T that satisfies the following Expressions 21 and 22 for an arbitrary natural number N. And supplies a drive signal to the motor 15 at an appropriate timing by detecting the phase of the drum 14 with a sensor (not shown).
1 and rotate until the sensor 152 detects the passage of the rear end of the film F. The rotation of the motor 151 operates the supply roller pair 143 to supply the film F to the drum 14. Note that, depending on the timing at which the film F is transported, the supply roller pair 1
43 may be rotating. Thus, when the drum 14 rotates to a predetermined position, the supply roller pair 143
Starts rotating, the following equations (21) and (22) are obtained.
The film F is supplied onto the outer peripheral surface of the drum 14 at a constant time interval T satisfying the following.

In this modification, the time TR during which the drum 14 makes one rotation and the leading end of the film F
When the constant time interval T supplied to the film 14 satisfies the above equation 21 with respect to an arbitrary natural number N, the drum 14 supplied between the continuously heated films F
Since the upper position is supplied at least 1/20 of the circumference of the drum, that is, by setting the amount of deviation between continuously supplied films to 360/20 = 18 degrees or more, the outer periphery of the drum 14 is supplied. The temperature distribution on the surface can be made uniform efficiently, whereby temperature unevenness in the rotation direction on the drum 14 is less likely to occur, and the occurrence of density unevenness in the image can be more effectively suppressed.

Further, the time TR during which the drum 14 makes one rotation and the shortest time interval Tmin at which the leading end of the film F is supplied to the drum 14 satisfy the above expression 22 for an arbitrary natural number N. Thus, the position on the drum 14 to be supplied is shifted at least 1/20 of the circumference of the drum even between every other film F continuously heated by the drum 14, so that the drum 1
4, the temperature unevenness in the rotation direction on the upper surface becomes less likely to occur,
Therefore, the occurrence of density unevenness can be more effectively suppressed.

<Modification 2> As a modification of this modification, the supply means includes a sensor 1 for detecting the leading end of the film.
52, a supply roller pair 143 provided on the upstream side in the transport direction of the sensor 152, a motor 151, and a control device 150 having a clock. When the sensor 152 detects the leading end of the film F, the sensor 152 Based on the time when the leading end of the film F was detected last time and two times before, and the clock thereof, the control device 150 controls the arbitrary natural number N at a constant time interval T that satisfies all of the above equations 21 and 22. Then, the drive signal is transmitted to the motor 151, and the film F is rotated until the sensor 152 detects the passage of the rear end of the film F. In other cases, the rotation of the supply roller pair 143 is stopped, and the film F conveyed from the lower conveyance unit 142 (FIG. 1) temporarily stops until a certain time interval T is reached. By the rotation of the motor 151,
The supply roller pair 143 operates to transfer the film F to the drum 1
4 can be supplied. Note that the supply roller pair 143 may be rotating depending on the timing at which the film F is transported.

Then, a sensor is provided in front of the exposure unit 120 so that the next film F does not overlap the film F in which the rotation of the supply roller pair 143 is stopped and stopped, and the film F is supplied by the supply roller pair 143. If it is detected by the start that the leading end of the next film F is about to pass, the transport roller 142 may be stopped in order to stop the next film F.

In this case, the feeding unit 110 supplies the next film F so that the film F is not supplied to the direction changing unit 145 until the next film F is supplied to the exposure unit 120. It is preferable not to start sending.

In this way, the control device 150
10A, the holding position of the film F is appropriately shifted, for example, as shown in FIG. 10A, so that the variation in the density of the image to be developed can be minimized. It becomes possible.・ ・ The above is the end of the modification.

Since the film F is held at an arbitrary position by the outer peripheral surface of the drum 14 and the roller 16,
It is not necessary to provide a film holding mechanism on the drum 14, but an appropriate chucking mechanism may be provided as needed.

When the shortest time interval Tmin is 27 seconds or less, the processing time when the thermal development of the film F is continued can be shortened. Is a hollow roller, the temperature of this roller is rapidly lowered, a temperature difference occurs between the front and rear ends of the heat developing material, and density unevenness occurs, but the heat developing material supplied to the drum contacts first. If the roller is a solid roller, density unevenness can be satisfactorily suppressed by a synergistic effect of suppressing this temperature difference and suppressing temperature unevenness caused by synchronizing the rotation period of the drum and the film supply interval.

When the shortest time interval Tmin is 27 seconds or less, the temperature of the surface of the elastic layer is liable to be drastically reduced only by thermally developing one heat developing material.
When n satisfies the following expression 8 or 9, the time TR during which the drum makes one rotation is relatively long with respect to the shortest time interval Tmin at which the tip of the thermal development material is supplied to the drum. 1. The temperature of the surface of the elastic layer, which has dropped due to thermal development of only one thermal developing material, can easily recover before the next thermal developing material is supplied, and the rotation cycle of the drum and the film supply interval are synchronized. Temperature unevenness due to the above-mentioned process, and the density unevenness can be synergistically suppressed. Equation 8: 19/20 × TR ≧ Tmin ≧ 21/40 × TR Equation 9: 26/20 × TR ≧ Tmin ≧ 21/20 × TR

In this case, when the time TR for one rotation of the drum 14 satisfies the following expression 10, the time for one rotation of the drum 14 is sufficient, and the development time is sufficiently long. Can reduce the winding angle of the film F, and the film F can be easily handled.
There is no need to bend the film F at a large angle when the film F is separated from the film F, the curl or the like is not easily generated in the thermally developed film F, and the effect of uniformly cooling the outer peripheral surface of the drum 14 by the film F is easily obtained. And uneven density can be suppressed. Note that the shortest time interval Tmin in this case is a fixed time interval T of the modification of the present embodiment.
Needless to say, it includes. Formula 10: 19/20 × TR ≧ Tmin ≧ 21/40 × TR

In this embodiment, the drum 14
The diameter D of the outer peripheral surface of the film and the length Lmax in the rotation direction of the film having the largest size in the rotation direction of the drum 14 are expressed by the following equation
To meet. Formula 6: π × D <2 × Lmax (π is a pi)

With such a configuration, the size of the drum 14 can be small, and the configuration of the heat developing apparatus 100 can be made compact. However, if this is simply done, in the case where the heat developing materials having different lengths along the rotation direction of the drum 14 are supplied to the drum 14, noticeable density unevenness occurs at the center of the screen of the heat developing material. However, as described above, by shifting the position on the outer peripheral surface of the drum 14 where the leading end of the film F is held, the occurrence of density unevenness in the central portion of the screen of the heat developing material can be suppressed well. Can be

On the other hand, the diameter D of the outer peripheral surface of the drum 14 for holding the film F, and the length L in the rotation direction of the film F whose length along the rotation direction of the drum 14 is the minimum.
When min satisfies the following expression 7, the drum diameter is increased in accordance with the rotational direction length of the heat development material, which has the minimum length along the rotational direction of the drum,
Since the development processing capacity can be increased, curling of the heat developing material can be suppressed, and the heat capacity of the drum can be set to a predetermined amount or more. Can be suppressed. Formula 7: Lmin <π × D (π is a circular constant) If the width of the heating area on the outer periphery of the drum 14 is formed larger than the width of the film F, a visible image can be formed over the entire surface of the film F. Becomes

Since the outer peripheral surface of the drum 14 must have smoothness, a temperature sensor for detecting the temperature of the drum 14 cannot be provided on the outer peripheral surface of the drum 14.
Needless to say, a temperature sensor is provided inside the device 4.
In the drum 14 of the present embodiment, the temperature sensor is provided in close contact with the inner periphery of the metal support member, and the sheet heater 32 is also provided in close contact with the inner periphery of the metal support member. The heating of the heater 32 is controlled according to the temperature detected by the temperature sensor.

However, the temperature difference between the temperature of the elastic layer surface and the temperature of the temperature sensor due to the difference in the position of the elastic layer surface and the temperature sensor depends on the timing of heating the film F (mainly, the film F is placed on the surface of the drum 14). (The timing at which the film F is supplied) is large, and the other timings are small. Therefore, there is a problem that the thermal development temperature substantially differs between the leading end and the trailing end of the film F, and density unevenness occurs.

Therefore, for example, the film F is transferred to the drum 14
Information about the timing of supplying on the surface of is obtained from the sensor 152 shown in FIG. 4, and according to the information,
A planar heater 32 provided in close contact with the inner periphery of the drum 14
By controlling the heating of the drum 14 by
By increasing the control target temperature of the heater 32 at the timing when the film F is supplied onto the surface of the drum 14 to a target temperature higher than the control target temperature of the heater 32 at other timings, the heating amount of the heater 32 is increased, At the timing when the film F is supplied onto the surface of the drum 14 and the other timing, the temperature of the surface of the elastic layer does not differ, and
The unevenness in temperature due to the adverse effect is suppressed, and the unevenness in temperature due to the synchronization of the rotation cycle of the drum 14 and the supply interval of the film F is suppressed.

FIG. 11 is an expanded view of the support tube 36 according to the present embodiment. Y direction is film F
And the X direction corresponds to the length direction of the film F. The outer peripheral surface of the drum 14 is on the lower surface side. The planar heater 32 is formed, for example, by rolling a nichrome wire w or the like at a fine pitch on the surface (inner peripheral surface) of the support tube 36. The central region 32 a and the side region 32 b adjacent in the Y direction are formed. , 32c. Each area 32a
32c, the heaters 32 can be independently controlled in temperature.

A groove 36a is formed on the inner surface of the support tube 36 between the side region 32b and the central region 32a.
Is formed on the inner surface of the support tube 36 between the central region 32a and the side region 32c.
Are formed. A wire-shaped temperature sensor S1 is arranged in the groove 36a, and a wire-shaped temperature sensor S2 is arranged in the groove 36b. The sensors S1 and S2 can measure not the temperature of the heater 32 but the temperature of the support tube 36 based on the self-resistance that changes with temperature. Although not shown, the heater 32 and the sensors S1 and S2 are covered with a heat insulating layer (not shown).

Here, when the film F having a width substantially equal to the width of the central region 32a is supplied to the drum 14, the central region 32a is cooled by the film F, so that the heater 32 applied to the central region 32a is not heated. Although the heating is controlled, the temperatures of the side regions 32b and 32c also increase accordingly.

In a region where the film F passes, the temperature sensor detects a temperature higher than the surface temperature of the drum 14, and in a region where the film F does not pass, the temperature sensor detects a temperature substantially equal to the surface temperature of the drum 14. And, in particular,
Shortest time interval Tmi for supplying film F to drum 14
If n is as short as 27 seconds or less, the time interval between the heat development of the previous film F and the supply of the next film F becomes very short, and the actual surface temperature of the drum 14 and the temperature sensor Since the difference between the detected temperatures becomes large, the heater control target temperature Te11 at the timing when the film F of the heater corresponding to the area where the film F does not pass over the drum surface, and the heater control target temperature at other timings Te12, a heater control target temperature Te21 at a timing at which the thermal development material of the heater corresponding to the area where the film F passes on the drum surface, and a heater control target temperature Te22 at other timings
Solves this problem by satisfying Equation 11 below. Formula 11: Te11−Te12 <Te21−Te22

That is, the temperature difference due to the difference between the position of the elastic layer surface and the position of the temperature sensor is larger in the area where the film F passes than in the other timings when the film F is heated. Although there is unevenness in the conveyance width direction where there is not much change in the area where no change occurs, by satisfying Expression 11, temperature unevenness due to these adverse effects is suppressed, and the rotation interval of the drum is synchronized with the film supply interval. Temperature unevenness can be suppressed, and density unevenness can be suppressed synergistically.

For example, in the area where the film F passes,
At the timing of supplying the film F to the drum 14, the control target temperature of the heater 32 is increased, and the film F is supplied to the drum 1.
At a timing other than the timing at which the toner is supplied to the drum 4, the control target temperature of the heater 32 is lowered, and the average temperature of the outer peripheral surface of the drum 14 can be made as uniform as possible. Not drum 1
The temperature unevenness due to the time of 4 can be suppressed, and the density unevenness can be favorably suppressed. In this embodiment, the temperature sensor is provided in close contact with the support tube 36 and measures the temperature of the support tube 36 to control the temperature. The temperature may be controlled by directly measuring the temperature.

It is to be noted that the value set substantially from the time when the leading end of the film F first contacts the drum 14 to the time when the trailing end of the film F first contacts the drum 14 and the value set during other periods. It is preferable that the temperature control is performed to achieve a certain value because smoothing of the temperature control is achieved when smoothing is performed by the ramp processing.

In the apparatus of this embodiment, the developing time is about 15 seconds, the drum diameter is about 0.161 m, and the angle with respect to the drum 14 provided with rollers (the drum 1 for thermal development).
4) is about 220 °, the time for one rotation of the drum 14 is 24.5 seconds, and the circumferential speed of the drum 14 is 0.02.
It is clear that it is 06 (m / sec). The maximum film size is 0.356 (m) x 0.432.
(M), which is a half cut size, and is the shortest time interval Tm from when the film F enters in the transport direction (3) to when the film F exits in the transport direction (4) in the transport direction conversion unit 145.
During “in”, Tmin is 38.3 seconds because the next film F is prevented from entering the transport direction conversion unit 145 so that the films F are not overlapped by the transport direction conversion unit 145.

The light-sensitive silver halide used in the heat-developable material is typically 0.75 to 25 with respect to the organic silver salt.
mol% can be used, preferably
It can be used in the range of 2 to 20 mol%.

The silver halide may be silver bromide, silver iodide, silver chloride, silver bromoiodide, silver chlorobromoiodide,
Any photosensitive silver halide such as silver chlorobromide may be used. The silver halide may be in any form that is photosensitive, including, but not limited to, cubic, orthorhombic, tabular, tetrahedral, and the like.

The organic silver salt is any organic material containing a source of reducing on silver. Organic acids, especially long chain fatty acids (10
-30 carbon atoms, preferably 15-28 carbon atoms)
Are preferred. When the ligand is 4.0 to 10.0 overall
It is preferable that the organic or inorganic silver salt complex has a certain stability between the two. Then, about 5% of the weight of the image forming layer
It is preferably about 30%.

The organic silver salt which can be used in the heat developing material is a silver salt which is relatively stable to light, and which contains an exposed photocatalyst (for example, photographic silver halide) and a reducing agent. Is a silver salt that forms a silver image when heated to a temperature of 115 to 120 ° C or higher.

Preferred organic silver salts include silver salts of organic compounds having a carboxyl group. They include silver salts of aliphatic carboxylic acids and silver salts of aromatic carboxylic acids. Preferred examples of the silver salt of an aliphatic carboxylic acid include silver behenate, silver stearate and the like. Silver salts with halogen atoms or hydroxyl in aliphatic carboxylic acids can also be used effectively. Silver salts of compounds having a mercapto or thione group and derivatives thereof can also be used. Further, a silver salt of a compound having an imino group can be used.

The reducing agent for the organic silver salt may be any material capable of reducing silver ions to metallic silver, and is preferably an organic material. Conventional photographic developers such as phenidone, hydroquinone and catechol are useful. However, phenol reducing agents are preferred. The reducing agent is used in the image forming layer.
It should be present at 10% by weight. In a multi-layer configuration,
If the reducing agent is added to a phase other than the emulsion layer, a slightly higher proportion, about 2 to 15% by weight, is more desirable.

In the case of thermal development at a development temperature of 80 ° C. or higher, the thermal development material is continuously supplied to the same position on the outer peripheral surface of the drum, and the thermal development is performed. Density unevenness tends to occur due to such a small temperature difference. However, since the time TR during which the drum makes one rotation and the shortest time interval Tmin at which the tip of the heat developing material is supplied to the drum satisfy the above-described formula 1 for an arbitrary natural number N, the heat developing material Is not continuously supplied to the same position on the outer peripheral surface of the drum, the occurrence of density unevenness is suppressed, and a good image can be obtained. In particular, when the measures described in the above-described embodiment are implemented, the occurrence of density unevenness is further suppressed, and a better image is obtained.

The heat-developable material contains photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent.
When the thermal development is performed at a temperature not lower than the minimum development temperature of 80 ° C. or higher, strong density unevenness occurs particularly due to a small temperature difference. Time interval T supplied to
min satisfies the above-described expression 1 for an arbitrary natural number N, so that the heat development material is not continuously supplied to the same position on the outer peripheral surface of the drum, and the occurrence of density unevenness is suppressed. In addition to obtaining a good image, the photosensitivity as a heat developing material is high, so that the exposure speed can be increased and an image can be formed with high productivity.

<Example of Improvement of Apparatus> An example in which the thermal developing apparatus of the above embodiment is further improved will be described below. Of the rotatable rollers 16 urged by the drum, at least the drum 1
A total of four rollers, the leading roller to which the film F supplied to the roller 4 first contacts and the subsequent roller, are not hollow, but are solid steel rollers.

Accordingly, if the shortest time interval Tmin
If the heat developing material supplied to the drum is a hollow roller, the temperature of the roller is rapidly reduced, and the temperature difference between the front end and the rear end of the heat developing material is rapidly reduced. However, if the roller to which the thermal developing material supplied to the drum comes into contact first is a solid roller, the heat capacity of the roller 16 is large, and thus the film F is heated from the back side by the roller 16. The temperature difference between the area where the film F is located and the other area is small, so that the development time can be shortened, and the temperature does not easily decrease even if the heat is taken away by the contacting film F. For example, it is possible to suppress density unevenness such as a difference in image density between the vicinity of the leading edge of the film and the vicinity of the trailing edge of the film. Satisfactorily suppressed density unevenness by a synergistic effect with the effect of suppressing the degree unevenness "may heat development a good image can be obtained.

When the shortest time interval Tmin is 27 seconds or less, the temperature of the surface of the elastic layer is liable to be drastically reduced only by thermally developing one heat developing material.
0.00070 (m) or less, and the thickness (m) of the elastic layer
Ratio of thermal conductivity (W / m / K) to 500 (W / m
² / K) or more, heat is transmitted well from the metal support member to the surface of the elastic layer, the temperature drop on the surface of the elastic layer is suppressed, and the rotation cycle of the drum and the film supply interval are synchronized. The density unevenness can be favorably suppressed by a synergistic effect with the effect of suppressing the temperature unevenness. The thermal conductivity of the elastic layer is preferably 0.4 (W / m / K) or more from the viewpoint of suppressing temperature unevenness in the elastic layer.

[0159]

Hereinafter, the film F will be described. Silver halide-silver behenate dry soap is disclosed in U.S. Pat.
Prepared by the method described in No. 049. The silver halide had 9 mole% of the total silver, while silver behenate had 91 mole% of the total silver. The silver halide was a 0.055 μm silver bromoiodide emulsion having 2% iodide.

The heat-developable emulsion was homogenized with 455 g of the above-mentioned silver halide-silver behenate dry soap, 27 g of toluene, 1918 g of 2-butanone, and polyvinyl butyral (B-79 manufactured by Monsanto). The homogenized heat-developed emulsion (698 g) and 60 g of 2-butanone were cooled to 12.8 ° C. while stirring. Pyridinium hydrobromide perbromide (0.92 g) was added and stirred for 2 hours.

3.25 ml of a calcium bromide solution (CaBr (1 g) and 10 ml of methanol) were added, followed by stirring for 30 minutes. Further, polyvinyl butyral (158 g; B-79 manufactured by Monsanto) was added, and 20
Stirred for minutes. The temperature was raised to 21.1 ° C. and the following was added with stirring over 15 minutes. 3.42 g of 2- (tribromomethylsulfone) quinoline, 28.1 g of 1,1-bis (2-hydroxy-3,5-dimethylphenyl) -3,5,5-trimethylhexane, 5-methylmercaptobenzimidazole Solution containing 0.545 g 41.1 g, 2- (4-chlorobenzoyl) benzoic acid 6.12 g S-1 (sensitizing dye) 0.104 g methanol 34.3 g Isocyanate (Desmoder N3300, manufactured by Mobay) 2.14 g Tetrachlorophthalic anhydride 0.97 g Phthalazine 2.88 g The dye S-1 has the following structure.

Embedded image

An active protection topcoat solution was prepared using the following components: 2-butanone 80.0 g methanol 10.7 g cellulose acetate butyrate (CAB-171-155, manufactured by Eastman Chemicals) 8.0 g 4-methylphthalate Acid 0.52 g MRA-1, Mottle reducing agent, N-ethyl perfluorooctanesulfonylamide ethyl methacrylate / hydroxyethyl methacrylate / acrylic acid weight ratio 70:20:10 Tertiary polymer 0.80 g

The heat-developable emulsion and the topcoat were simultaneously coated on a 0.18 mm blue polyester film base. The knife coater was set up with two bars or knives coating simultaneously at a distance of 15.2 cm. The silver trip layer and the top coat were multi-layer coated by pouring the silver emulsion on the film prior to the rear knife and the top coat on the film prior to the front bar.

The film was then pulled forward so that both layers were coated simultaneously. This was obtained by performing the multilayer coating method once. The coated polyester base was dried at 79.4 ° C. for 4 minutes. As the knife, as dry coating weight per 1 m ² for the silver layer is 23g, then dry coating weight per 1 m ² is adjusted so as to be 2.4g for the top coat Was.

The film F applied in this manner is 0.1 to 0.1%.
356 (m) x 0.256 (m) (14 x 10 inches)
A large number of film F of large quarter section and 0.356
It was cut into a large number of films F (m) × 0.432 (m), which were cut in half, and laminated. Then, a light-shielding film for accommodating the stacked 126 films F for each size until the film F was set in the case C was prepared. And
For each size, 126 films F laminated by the prepared light-shielding film were light-shielded and packaged.

(Experiment) Then, for the following experiment, in the first case C, a light-shielded and wrapped large-sized film F was set, the package was opened in a light-shielded state, and the light-shielded film was removed. The film F was set in a state where it can be supplied. Similarly, in the second case C, a half-sized film F light-shielded and wrapped was set, the package was opened in a light-shielded state, the light-shielded film was removed, and the film F was set in a state in which the film F could be supplied. When the film F supplied from any of the cases C is supplied to the drum 14, the size in the transport width direction is 0.356 (m), that is, the size in the transport direction is different. , Case C
Is set to

Experiment 1 The above-mentioned heat developing apparatus (all rollers 16 are hollow rollers, an aluminum tube having a thickness of 1 mm and a reputation of 2.18 cm), and an aluminum support tube 36 of the drum 14 having a length of 45.7cm, outer diameter 16cm, wall thickness 0.6
4 cm, the soft layer 38 has a surface roughness of 2.3 μm or more and 3.2 μm or less, a thickness of 0.5 mm, a variation of 5% or less, a thermal conductivity of 2 W / m / K, and a shore. A hardness is 55, and is an elastic layer containing a silicon-containing elastic material) at the timing when various compressed image data having three rows of uniform density regions at both ends in the width direction and the center can be restored. By exposing and supplying, at the timing of supplying one film F at random timing and, on average, the time corresponding to two rotations of the drum, 100 sheets of the above-described large-section film F are used. The film was heat developed. The abundance of natural numbers n satisfying the expressions (5) to (7) was about 90%. And these 100 films F
Immediately after the thermal development (within the time corresponding to two rotations of the drum), the film F having a half-cut size was thermally developed.

Experiment 2 The image data of Experiment 1 was converted to substantially the same image data by the above-mentioned thermal developing apparatus, so that the time interval of the supplied large-sized film F was substantially equal to the time for two rotations of the drum. Controlling to be equal, using the above-mentioned film F,
One hundred films were heat developed. The abundance of natural numbers n satisfying the expressions (5) to (7) was about 60%. Immediately after these 100 films F were thermally developed (within two rotations of the drum), the half-size film F was thermally developed.

Experiment 3 (Comparative Example) In the above-described thermal developing apparatus, the image data of Experiment 1 was changed to substantially the same image data. Is controlled to be exactly equal to the time of
One hundred films were heat developed. The abundance of natural numbers n satisfying the expressions (5) to (7) was 0%. Immediately after these 100 films F were thermally developed (within two rotations of the drum), the half-size film F was thermally developed.

Experiment 4 The shortest time interval Tmin was increased by increasing the transport speed to the transport direction changing unit 145 in the above-described thermal developing apparatus.
Tmin = 0.9 × TR, minimum time interval Tmi
By exposing and supplying various compressed image data having a uniform density region of three rows at both ends and the center in the width direction at timing of a time interval of n or more, and supplying the compressed image data, random At the timing and, on average, at the timing of supplying one film F in the time of one rotation of the drum, using the film F of the above-mentioned large quarter size,
One hundred films were heat developed. The abundance of natural numbers n satisfying the expressions (5) to (7) was about 80%. Immediately after these 100 films F were thermally developed (within two rotations of the drum), the half-size film F was thermally developed.

Experiment 5 In the above-described thermal developing apparatus, the shortest time interval Tmin was increased by increasing the transport speed to the transport direction changing unit 145.
Tmin = 1.1 × TR, minimum time interval Tmi
By exposing and supplying various compressed image data having a uniform density region of three rows at both ends and the center in the width direction at timing of a time interval of n or more, and supplying the compressed image data, random At the timing and, on average, at the timing of supplying one film F in the time of one rotation of the drum, using the film F of the above-mentioned large quarter size,
One hundred films were heat developed. The abundance of natural numbers n satisfying the expressions (5) to (7) was about 90%. Immediately after these 100 films F were thermally developed (within the time corresponding to one rotation of the drum), a half-cut film F was thermally developed.

Experiment 6 (Comparative Example) In the above-described thermal developing apparatus, by increasing the transport speed to the transport direction conversion unit 145, the same image data was obtained.
100 films were thermally developed using the above-mentioned film F by controlling so that the time interval of the supplied film F of the large quarter size was exactly equal to the time for one rotation of the drum. The existence rate of the natural number n satisfying the expressions (5) to (7) is
It was 0%. Immediately after these 100 sheets of film F have been subjected to thermal development (within one drum rotation).
Then, a half-size film F was heat-developed.

Experiments 7 to 12 All the rollers 16 were 2 cm in diameter from the above-mentioned heat developing apparatus.
And the aluminum support tube 36 of the drum 14 is 45.7 cm long and 16 c outside diameter.
m, the thickness is 0.72 cm, the flexible layer 38 has a surface roughness of 2.3 μm or more and 3.2 μm or less, a thickness of 0.5 mm, a variation of 5% or less, and a thermal conductivity of 2W /
The experiment was performed in the same manner as in Experiments 1 to 6, except that the elastic layer was m / K, the Shore A hardness was 55, and the elastic layer contained a silicon-containing elastic material.

Evaluation. Maximum Density Difference in Film For each of the 100 films, the density at the leading end, center, and rear end in the transport direction was measured with a densitometer, and the measured maximum density difference in the film was determined. And it evaluated by the maximum value of this maximum density difference.

Evaluation. Visual Evaluation 100 films F were visually evaluated according to the following criteria. (Criterion) A: Density unevenness was not found, and a good image was obtained. B: There was a film with some density unevenness, but a substantially good image was obtained at a level almost indistinguishable. C: Density unevenness was slight, but at a practical level. D: Density unevenness was found, and it was at a level of whether or not it could be practically used. E: Density unevenness was apparent, and the level was not suitable for practical use. F: Fifth and subsequent films cannot be practically used because there is noticeable density unevenness. G: Not practical because there is noticeable density unevenness from the second and third films.

Evaluation. Maximum density difference within half-cut size 100 half-film F is heat-developed immediately after heat-development of half-size film F.
The densities at the center and at the rear end were measured with a densitometer, and the maximum density difference in the measured film was determined. Evaluation. Immediately after 100 sheets of the film F were continuously heat-developed, the heat-developed half-cut size film F was visually evaluated according to the following criteria. A: No density unevenness was found, and a good image was obtained. B: Substantially good image was obtained at a level where density unevenness was slight but hardly recognized. C: Density unevenness was slight, but at a practical level. D: Density unevenness was found, and it was at a level of whether or not it could be practically used. E: Clear density unevenness was found at the center of the screen, and the level was not suitable for practical use. F: Since there is noticeable density unevenness at the center of the screen, it cannot be used practically. G: Practically impossible because there is a strongly noticeable density unevenness in the center of the screen.

Experimental Results Experiment: Tmin: Evaluation: Evaluation: Evaluation: Evaluation Experiment 1: 38.3: 0.10: A: 0.10: A: Example Experiment 2: 38.3: 0.15: C: 0.20: C: Example Experiment 3: 38.3: 0.25: F: 0.30: F: Comparative Example Experiment 4: 22.1: 0.20: C: 0.20: C: Example Experiment 5: 26.9: 0.20: C: 0.15: C: Example Experiment 6: 24.5: 0.30: G: 0.35: G: Comparative Example Experiment 7: 38.3: 0 .10: A: 0.10: A: Example Experiment 8: 38.3: 0.15: C: 0.20: C: Example Experiment 9: 38.3: 0.25: F: 0.30 : F: Comparative example Experiment 10: 22.1: 0.10: A: 0.10: A: Example Experiment 11: 26.9: 0.10: A: 0.10 : A: Example Experiment 12: 24.5: 0.30: G: 0.35: G: Comparative Example

According to the present invention, the occurrence of density unevenness in the heat-developable material can be suppressed.

[Brief description of the drawings]

FIG. 1 is a front view of a heat developing device according to an embodiment of the present invention.

FIG. 2 is a left side view of the heat developing device according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating a configuration of an exposure unit 120.

FIG. 4 is a diagram illustrating a configuration of a developing unit that heats a film, and is a perspective view of the developing unit.

5 is a cross-sectional view of the configuration of FIG. 4 taken along line IV-IV and viewed in the direction of the arrow.

FIG. 6 is a front view of the configuration of FIG. 4;

FIG. 7 is a cross-sectional view of the film F, schematically showing a chemical reaction in the film F during exposure.

FIG. 8 is a cross-sectional view similar to FIG. 7, schematically showing a chemical reaction in the film F during heating.

FIG. 9 is a diagram for explaining a problem of the related art.

FIG. 10 is a diagram for explaining a mode of reducing density variations of an image according to the present embodiment.

FIG. 11 is an expanded view of a support tube 36 according to another embodiment.

FIG. 12A is a diagram showing the position of the film F when the film F is continuously supplied to the drum 14 at the shortest time interval Tmin, and FIG.
12 is a diagram showing a temperature distribution on the outer peripheral surface of FIG.
FIG. 4 is a diagram showing a density distribution of a thermally developed film F.

DESCRIPTION OF SYMBOLS 14 Drum 16 Roller 18 Frame 21 Guide bracket 28 Coil spring 30 Reinforcing member 32 Heater 34 Control electronics 38 Flexible layer 100 Thermal developing device 110 Storage unit 120 Exposure unit 130 Developing unit 143 Supply roller pair 150A Cooling unit 150 Control unit 151 Motor F Film

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yosuke Tateishi 591-7 Kamihirose, Sayama City, Saitama Prefecture Konica Corporation (72) Inventor Yasuaki Tamakoshi 591-7, Kamihirose, Sayama City, Saitama Prefecture Konica Corporation

Claims (17)

[Claims] 1. An elastic layer having a thickness of 0.1 mm or more on a surface thereof and a metal support for directly or indirectly supporting the elastic layer, wherein the thermal developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a plurality of rotatable rollers urged against the drum, and a supply unit for supplying a sheet-like heat developing material on an outer peripheral surface of the drum, and supplied by the supply unit. In a heat developing device that thermally develops the heat developing material by heating while holding the heat developing material on the outer peripheral surface of the drum by the plurality of rollers,
The elastic layer has a thickness of 2 mm or less and a thermal conductivity of 0.4 (W
/ M / K) or more, and at least between the thermal developing materials continuously heated by the drum, the position on the drum to which the tip of the thermal developing material is supplied is A heat developing apparatus, wherein the heat developing material is supplied to the drum at a timing shifted in a rotation direction of the drum. 2. An elastic layer having a thickness of 0.1 mm or more on the surface and a metal support for directly or indirectly supporting the elastic layer, wherein the thermal developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a plurality of rotatable rollers urged against the drum, and a supply unit for supplying a sheet-like heat developing material on an outer peripheral surface of the drum, and supplied by the supply unit. In a heat developing device that thermally develops the heat developing material by heating while holding the heat developing material on the outer peripheral surface of the drum by the plurality of rollers,
The elastic layer has a thickness of 2 mm or less and a thermal conductivity of 0.4 (W
/ M / K) or more, and the time for the drum to make one rotation is TR
The time interval between the time when the leading edge of the n-th supplied thermal developing material is supplied to the drum and the time when the leading edge of the n + 1-th supplied thermal developing material is supplied to the drum is T (n).
Then, for an arbitrary natural number N, the following Expressions 3 to 5
Wherein the abundance of natural numbers n satisfying all of the following conditions is 50% or more. Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) 3. A drum for heating the heat developing material on the outer peripheral surface while rotating at a constant rotation speed, and a supply unit for supplying a sheet-like heat developing material on the outer peripheral surface of the drum, The supply means supplies the heat development material to the drum at a predetermined conveyance speed through a predetermined supply path for supplying the heat development material, and has an exposure means for exposing the heat development material on the supply path. In the thermal developing apparatus for thermally developing the thermal developing material by heating while maintaining the thermal developing material supplied by the supply unit on the outer peripheral surface of the drum, a time TR during which the drum makes one rotation; The shortest time interval Tm at which the tip of the thermal developing material is supplied to the drum
in satisfies the following formulas 1 and 2 for an arbitrary natural number N; The exposure means is based on image data formed at random time intervals, the shortest time interval Tmin, or, when exceeding the shortest time interval Tmin, by exposing the heat developing material at random time intervals, The supply means may be the shortest time interval Tmin or the shortest time interval Tm
When the time exceeds in, the heat development material is supplied to the drum at random time intervals, and the time during which the drum makes one rotation is TR, and the time at which the tip of the nth supplied heat development material is supplied to the drum And T (n) is the time interval between the time at which the tip of the thermal developing material supplied to the n + 1-th and the time at which the tip of the thermal developing material is supplied to the drum, a natural number that satisfies all of the following Expressions 3 to 5 for an arbitrary natural number N A thermal developing apparatus wherein the abundance of n is 50% or more. Equation 3: (N−1 / 20) × TR ≧ T (n) or (N + 1/20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1) / 20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) 4. The supply means has a transport direction conversion unit for converting the transport direction by transporting the thermally developed material carried in from the carry-in direction to a carry-out direction different from the carry-in direction in the supply path. Then, the transport direction conversion unit carries out the thermal development material by carrying out the thermal development material before carrying out the thermal development material, so that the time interval with the thermal development material carried out earlier is not less than the minimum time interval Tmin, The heat developing device according to claim 3, wherein the material is carried out. 5. A drum for heating the heat developing material on the outer peripheral surface while rotating at a constant rotation speed, a plurality of rotatable rollers urged by the drum, and a sheet-shaped roller on the outer peripheral surface of the drum. Supply means for supplying a thermal developing material of
While holding the thermal developing material supplied by the supplying means on the outer peripheral surface of the drum by the plurality of rollers,
At a developing temperature of 0 ° C. or higher, for a predetermined thermal developing time, a thermal developing apparatus that thermally develops a thermal developing material by heating,
At least between the thermal development materials supplied to the drum at the time interval of the shortest time interval Tmin, the supply unit shifts the position where the tip of the thermal development material is held in the rotation direction of the drum. The thermal developing material is supplied to the drum at a timing, the minimum time interval Tmin is 27 seconds or less, and the thermal developing material is supplied to at least the drum among rotatable rollers urged by the drum. A heat developing device, wherein a roller which contacts the heat developing material first is a solid roller. 6. An elastic layer having a thickness of 0.1 mm or more on a surface thereof and a metal support for directly or indirectly supporting the elastic layer, wherein the heat developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a guide member urged by the drum, and a supply unit for supplying a sheet-like thermal development material on the outer peripheral surface of the drum, and the heat development supplied by the supply unit. While holding the material on the outer peripheral surface of the drum by the guide member, at a developing temperature of 80 ° C. or more,
In a heat developing device that heats the heat developing material by heating for a predetermined heat developing time, at least between the heat developing materials supplied to the drum at time intervals of the shortest time interval Tmin, The means supplies the thermal developing material to the drum at a timing at which the tip of the thermal developing material is held is shifted in the rotation direction of the drum, and the shortest time interval Tmin is 27 seconds or less. Wherein the thickness of the elastic layer is 0.70 mm or less, and the thermal conductivity (W /
m / K) is 50 (W / m ² / K) or more. 7. An elastic layer having a thickness of 0.1 mm or more on a surface thereof and a metal support for directly or indirectly supporting the elastic layer, wherein the thermal developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a guide member urged by the drum, and a supply unit for supplying a sheet-like thermal development material on the outer peripheral surface of the drum, and the heat development supplied by the supply unit. While holding the material on the outer peripheral surface of the drum by the guide member, at a developing temperature of 80 ° C. or more,
In a heat developing device that heats the heat developing material by heating for a predetermined heat developing time, at least between the heat developing materials supplied to the drum at time intervals of the shortest time interval Tmin, The means supplies the thermal developing material to the drum at a timing at which the tip of the thermal developing material is held is shifted in the rotation direction of the drum, and the shortest time interval Tmin is 27 seconds or less. Wherein the shortest time interval Tmin satisfies the following expression 8 or 9 with the TR. Equation 8: 19/20 × TR ≧ Tmin ≧ 21/40 × TR Equation 9: 26/20 × TR ≧ Tmin ≧ 21/20 × TR 8. The thermal developing apparatus according to claim 7, wherein the shortest time interval Tmin satisfies the following equation (10) with the TR. Formula 10: 19/20 × TR ≧ Tmin ≧ 21/40 × T
R 9. An elastic layer having a thickness of 0.1 mm or more on the surface and a metal support for directly or indirectly supporting the elastic layer, wherein the thermal developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a guide member urged by the drum, and a supply unit for supplying a sheet-like thermal development material on the outer peripheral surface of the drum, and the heat development supplied by the supply unit. While holding the material on the outer peripheral surface of the drum by the guide member, at a developing temperature of 80 ° C. or more,
In a heat developing device that heats the heat developing material by heating for a predetermined heat developing time, the time for one rotation of the drum is TR, and the tip of the n-th supplied heat developing material is supplied to the drum. The time interval between the time at which the thermal development material supplied to the (n + 1) th supply is supplied to the drum is defined as T.
Assuming that (n), for any natural number N, the following equation 3
-The existence rate of the natural number n that satisfies all of the expressions 5 is 50% or more, and the expression 3: (N-1/20) x TR ≥ T (n) or (N + 1/20) x TR ≤ T (n) Expression 4 : (N−1 / 20) × TR ≧ T (n + 1) or (N + 1/20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) A temperature sensor and a planar heater are provided in close contact with the inner periphery of the metal support member, and are provided according to the temperature detected by the temperature sensor. A thermal developing apparatus for controlling heating of the heater, wherein a control target temperature of the heater at a timing when the thermal developing material is supplied onto the drum surface is higher than other control timings. 10. An elastic layer having a thickness of 0.1 mm or more on a surface and a metal support for directly or indirectly supporting the elastic layer, wherein the thermal developing material on the outer peripheral surface is heated while rotating at a constant rotation speed. A drum having a member, a guide member urged by the drum, and a supply unit for supplying a sheet-like thermal development material on the outer peripheral surface of the drum, and the heat development supplied by the supply unit. A heat developing apparatus for thermally developing a thermally developed material by heating at a development temperature of 80 ° C. or more for a predetermined thermal development time while holding the material on the outer peripheral surface of the drum by the guide member, Is the time when the tip of the n-th supplied thermal developing material is supplied to the drum, and the time interval between the time when the leading edge of the n + 1-th supplied thermal developing material is supplied to the drum. Is T (n), For any natural number N, the existence rate of the natural number n that satisfies all of the following Expressions 3 to 5 is 50% or more; Expression 3: (N−1 / 20) × TR ≧ T (n) or (N + 1) / 20) × TR ≦ T (n) Equation 4: (N−1 / 20) × TR ≧ T (n + 1) or (N + 1/20) × TR ≦ T (n + 1) Equation 5: (N−1 / 20) × TR ≧ T (n) + T (n + 1) or (N + 1/20) × TR ≦ T (n) + T (n + 1) For each of a plurality of regions that divide the drum on the inner periphery of the metal support member in the conveyance width direction. A temperature heater and a planar heater provided in close contact with the metal support member, and a timing for supplying the thermal developing material of the heater corresponding to an area through which the thermal developing material does not pass onto the drum surface. Control target temperature Te11 of the heater at the time, the heater at other timing The control target temperature Te12, the heater control target temperature Te21 at the timing of supplying the thermal developing material of the heater corresponding to the area through which the thermal developing material passes onto the drum surface, and the heater at the other timings Of the control target temperature Te22 of the following equation 1
12. The thermal developing apparatus according to claim 11, wherein the following condition is satisfied. Formula 11: Te11−Te12 <Te21−Te22 11. The thermal developing apparatus according to claim 9, wherein a ramp process is performed by controlling heating of the heater. 12. At least between the thermal developing materials supplied to the drum at a time interval of the shortest time interval Tmin, the supply means determines that the position at which the tip of the thermal developing material is held is the position of the drum. The thermal developing material is supplied to the drum at a timing of shifting in the rotation direction, and a time TR during which the drum makes one rotation and a minimum time interval Tmin during which the tip of the thermal developing material is supplied to the drum
Satisfies the following expression 1 with respect to an arbitrary natural number N. The thermal developing apparatus according to claim 3, wherein 13. A time TR during which the drum makes one revolution,
The shortest time interval Tmin at which the leading end of the heat developing material is supplied to the drum is expressed by the following equation (2) for an arbitrary natural number N.
The thermal developing device according to claim 12, wherein the following condition is satisfied. 14. The supply means for supplying to the drum thermal development materials having different sizes along the rotation direction of the drum, and a diameter D of the outer peripheral surface of the drum.
And the length Lmax in the rotational direction of the thermal developing material having the maximum length along the rotational direction of the drum among the thermal developing materials supplied by the supply unit satisfies the following expression 6. The heat developing apparatus according to claim 1. Formula 6: π × D <2 × Lmax (π is a pi) 15. The diameter of the outer peripheral surface of the drum that holds the heat development material and the length of the heat development material supplied by the supply unit along the rotation direction of the drum are the minimum. The rotational direction length Lmin of the heat developing material is
The heat developing device according to claim 1, wherein the following formula 7 is satisfied. Formula 7: Lmin <π × D (π is a pi) 16. The heat-developable photosensitive material is a sheet-shaped heat-developable material containing photosensitive silver halide particles, an organic silver salt, and a silver ion reducing agent and having a minimum heat development temperature of 80 ° C. or higher. The thermal developing device according to claim 1, wherein 17. The heat developing apparatus according to claim 1, wherein a sheet containing photosensitive silver halide grains, an organic silver salt, and a silver ion reducing agent and having a minimum heat development temperature of 80 ° C. or higher. A thermal development method, comprising thermally developing a heat-developable material in the shape of a circle.