JPH0811331A - Image forming apparatus - Google Patents

Abstract

PURPOSE:To provide an image forming apparatus having the merits of an electrophotographic system and a thermal recording system, imparting high image quality and excellent in durability. CONSTITUTION:An image forming apparatus has a photothermal recording member 2 constituted by successively forming an amorphous silicon photoconductive layer 4, a conductive layer 5 and a surface protective layer 6 on a cylindrical light previous conductive support 3, the light irradiation means 7 emitting pulse beam arranged in the recording member 2, the peripheral surface press member 9 arranged outside the irradiation means 7 in opposed relation thereto and pressing thermal recording paper or recording paper 8 on which an ink film 16 is superposed to the outer peripheral surface of the photothermal recording member 2 in a planar state and the cooling means 12 of the photothermal recording member 2. Photothermal recording is performed by irradiating the photothermal recording member 2 with pulse beam while applying voltage across the light previous conductive support 3 and the conductive layer 5. A hot-melt ink coating means, a thermally fixable toner coating means or a toner supply means is arranged to the surface of the photothermal recording member 2 or peripheral surface press means 9 to apply recording to plain paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermosensitive recording type image forming apparatus, and more particularly to an image forming apparatus using a photothermographic recording body having a light irradiating means arranged therein.

[0002]

2. Description of the Related Art As a recording device for image or character information,
Image forming devices and printing devices using various methods, such as wire dot impact, color development type or transfer type thermal (thermal recording), inkjet, electrophotography, electrostatic recording, etc., are known, and are currently widely used by taking advantage of their respective characteristics. ing.

Among the above-mentioned methods, the electrophotographic method represented by the Carlson method has advantages such as high recording speed, excellent image quality, and good storability of recorded images due to plain paper recording. And is widely used as a high-speed and high-quality image forming apparatus.

In the Carlson method, however, corona charging, exposure, development, and
Means for transferring, fixing, cleaning and discharging are arranged, and an image is formed on a recording paper through many processes. Therefore, the configuration of the device is complicated and it is difficult to reduce the size,
Alternatively, the corona discharge for charging the photoconductor is usually 5
There is a problem that a high voltage power supply of up to 7 kV is required, handling is dangerous, and ozone is generated due to the discharge to adversely affect the surroundings.

Amorphous selenium (a-Se) system and amorphous silicon (a-Si) are used for the photosensitive member.
Although a photoconductive material such as a system or various organic photoconductors (OPC) is used, a thick photosensitive layer having a thickness of 20 to 80 .mu.m is usually required for charging to a surface potential of 400 to 1000V.

Further, in the electrophotographic image forming apparatus, there is a problem of dust collection contamination and corona wire contamination in the corona charger, or contamination in the apparatus due to toner scattering from the developing device. There are also problems such as the life of the cleaning means due to wear of the cleaning blade, and the life of the developer due to wear of the developer coating and deterioration of its characteristics.In actual use, regular maintenance (maintenance work such as cleaning, adjustment, etc. And parts replacement) was required quite often.

Therefore, as a method of simplifying the periodical maintenance, a method of replacing a cartridge in which the main part of the image forming process is integrated according to the wear and deterioration of parts has been developed, which is particularly used in the field of personal use. Is increasing rapidly. However, the replacement cost of the cartridge is high,
Moreover, when used cartridges are thrown away, they cause a problem of industrial waste, and it takes a lot of time and cost to collect and reuse the cartridges from end users to a reprocessing plant. .

By the way, recently, an electrophotographic method which does not require corona charging has been proposed (Japanese Patent Publication No. 2-4900, Japanese Examined Patent Publication).
60-59592, JP-A-58-153957, etc.). According to this method, a drum-shaped or belt-shaped photosensitive member in which a transparent conductive layer and a photosensitive layer are sequentially formed on a transparent support is exposed from the transparent support side and a developing bias voltage is applied. The surface of the photoconductor is rubbed with a magnetic brush made of conductive magnetic toner on the applied developing device, whereby charging, exposure, and development are performed almost simultaneously to form a toner image on the photoconductor. This toner image is transferred onto recording paper using a transfer roller or a corona transfer device, and is fixed by a fixing means to form a recorded image, while the toner remaining on the photoconductor after transfer is collected by a developing device and reused. To be done.

In the electrophotographic system which does not require corona charging, there is a problem that recording on plain paper is difficult because a conductive toner is used as a developer, but a combination of a conductive carrier and an insulating toner is used. A two-component developer has been proposed, and good plain paper recording is becoming possible. Since the image forming process is simpler than that of the Carlson method, the size of the apparatus becomes smaller, ozone is not generated by charging, and the charging potential is as low as 30 to 100 V. Therefore, the photosensitive layer thickness of the photoconductor is several to ten. It has the advantage that several μm is sufficient. However, it has not yet been put to practical use.

On the other hand, the heat-sensitive recording system represented by a color-forming type or transfer-type thermal has a small recording voltage, can be directly driven by an integrated circuit, does not generate noise during recording, and causes environmental problems such as ozone generation. It is widely used in small-sized image forming apparatuses because it has advantages such as a simple structure, an advantage in size reduction, weight reduction, and cost reduction.

The recording principle of the color-developing thermal is that a thermal head having a large number of minute heating elements is brought into contact with a heat-sensitive recording paper which receives heat to develop color, and the heating elements are selectively driven to generate heat. This is for recording by recording color on a thermosensitive recording paper. This type of image forming apparatus has a simple structure and high reliability.

The transfer-type thermal recording principle is that the recording film such as plain paper is brought into close contact with an ink film coated with heat-melting ink or sublimable ink and brought into contact with the thermal head. Is a method of melting or sublimating and transferring to a recording paper, and is a method that solves the drawback of the color-developing thermal relating to the recording storability while utilizing the simplicity of the thermal recording method. As the heat-meltable or sublimable ink applied to the ink film, a mixture of a coloring material such as pigment or dye with a binder such as wax is used, and colorization is also realized by changing the coloring material.

In any of the above thermal recording systems, a thermal head is used as the recording medium. This thermal head, if it is a so-called line head, has 2000 to 3000 minute heating elements arranged in series (in a line), and the recording information is sequentially input to the heating element as a serial electric signal to scan in the main scanning direction. A two-dimensional image is obtained by running the recording paper and performing recording in the sub-scanning direction while performing the recording.

However, since this heating element cannot continuously generate heat and requires cooling time, the heating element is usually divided into several blocks and driven. Therefore, there is a limit to increase the recording speed. Further, since the minimum dot (pixel) size for recording is determined by the element size of the heating element of the thermal head formed in the photo-etching process, miniaturization of the heating element to improve the recording density is complicated and difficult to manufacture. Therefore, there is a problem that the cost becomes high, it is difficult to secure reliability, and the recording life is shortened. As described above, the thermal recording method using the conventional thermal head has a problem that it is difficult to obtain a high-resolution image. Furthermore, the ink film necessary for recording on plain paper is mostly disposable except for the part that is transferred to plain paper.
There is also a problem that it is wasteful and the running cost is high.

Regarding the recording material of such a heat sensitive recording system, the present inventors have recently proposed a light heat sensitive recording method utilizing photoelectric conversion for driving a heating element (Japanese Patent Application No. 63-335127).
No., Japanese Patent Application No. 4-171122, etc.). According to this method, a transparent electrode, a photoconductive layer or a photoconductive layer and a heating resistor layer, a second electrode, and a protective layer as needed are sequentially formed on a transparent substrate. Thermal recording is performed by applying the voltage between the translucent electrode and the second electrode and applying light to the photoconductive layer from the substrate side to energize the photoconductive layer to generate heat and to generate heat. . Since the optical signal is used for writing the recording information in this manner, a complicated manufacturing process such as a heating element such as a thermal head or an electrode pattern formation is not required, and a high-sensitivity photothermal recording method with high resolution can be realized. It is a thing.

[0016]

However, even in the electrophotographic system which does not require corona charging, an image forming process for charging, exposing and developing at substantially the same time and a plurality of processes such as transfer and fixing are required. Therefore, it is difficult to reduce the size to the same as that of the thermal recording type device. Further, since the same developing device as that used in the Carlson method is used, there is a problem that the inside of the device is contaminated due to toner scattering, and there is also a problem that maintenance work is required.

On the other hand, even in the above-described light and heat sensitive recording system, an ink film is used for recording on plain paper, and therefore improvement in running cost has been desired. Further, in Japanese Patent Application No. 63-335127, since a flat plate-shaped substrate is used, when the recording speed is increased, the light irradiation time per dot is drastically shortened and it becomes difficult to obtain a sufficient heat generation amount. It was difficult to increase the recording speed sufficiently. Further, Japanese Patent Application No. 4-171122 proposes to apply a heat-melting ink to the surface of the recording material in advance, and to attach the ink of only the heat-generating portion irradiated with light to the plain paper, The structure of the apparatus for applying the heat-meltable ink and the control of the melting and solidification of the ink are complicated, and improvements for increasing the recording speed have been desired.

The present invention has been completed in view of the above circumstances, and an object thereof is to reduce the image recording process while ensuring the image quality and recording speed equivalent to those of the electrophotographic system.
An object of the present invention is to provide an image forming apparatus which is excellent in image reproducibility and resolution, which is capable of reducing the size and cost of the apparatus and reducing maintenance work, does not generate ozone, and does not cause environmental problems.

Another object of the present invention is to make the structure of the recording medium simpler than that of the thermal recording system, to increase the image resolution while making the recording medium easy to manufacture and high in reliability, high in recording speed and high in image quality. To provide a long-life image forming apparatus.

Still another object of the present invention is to provide an image forming apparatus of the photothermographic recording type, which has a high recording speed and reduces the running cost of plain paper recording.

Still another object of the present invention is to use an amorphous silicon photoconductive layer having high hardness and excellent heat resistance as the photoconductive layer of the recording medium, and to provide an optical signal from a light irradiating means arranged inside the recording medium. An object of the present invention is to provide an image forming apparatus of a photothermographic recording system of high image quality, stable image characteristics, and high reliability, which performs heat-sensitive recording by converting recorded information to be written as heat.

[0022]

According to a first aspect of the present invention, in an image forming apparatus, an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer are sequentially provided on a cylindrical translucent conductive support. Formed photothermographic material, light irradiating means arranged inside the light sensitive recording body and radiating pulsed light, and arranged outside the light sensitive recording body so as to face the light irradiating means. A peripheral pressure member that presses the recording paper on which the thermal recording paper or the ink film is superposed on the outer peripheral surface of the photothermographic recording medium, and a cooling unit that lowers the temperature of the outer peripheral surface of the thermal recording medium. Is to have.

The image forming apparatus according to claim 2 of the present invention is
On a cylindrical translucent conductive support, a photothermographic recording medium formed by sequentially forming an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer, and arranged inside the photothermographic recording medium,
A light irradiating means for irradiating pulsed light and a peripheral surface-applying member which is arranged outside the light-sensitive thermosensitive recording medium so as to face the light-irradiating means and presses the recording paper in a planar manner on the outer peripheral surface of the light-sensitive thermal recording material. It has a pressure body, a cooling means for lowering the temperature of the outer peripheral surface of the light-sensitive recording body, and an ink application means for applying a heat-melting ink to the outer peripheral surface of the light-sensitive recording material.

An image forming apparatus according to a third aspect of the present invention is formed by sequentially forming an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer on a cylindrical translucent conductive support. A photothermographic recording medium, a light irradiation unit arranged inside the photothermographic recording unit for irradiating pulsed light, and a light irradiation unit arranged outside the photothermographic recording unit so as to face the light irradiation unit. A peripheral pressure member that presses the outer peripheral surface of the recording body in a planar manner, an ink applying unit that applies a heat-meltable ink to the surface of the peripheral pressure body, and a recording paper on the outer peripheral surface of the photothermographic recording body. And a cooling unit for lowering the temperature of the outer peripheral surface of the photothermographic recording medium.

An image forming apparatus according to a fourth aspect of the present invention is the image forming apparatus according to the second or third aspect, wherein the heat fixing property is replaced with the ink applying means for applying the heat-meltable ink. It is characterized in that a toner application means for applying toner is provided.

Further, the image forming apparatus according to a fifth aspect of the present invention is formed by sequentially forming an amorphous silicon type photoconductive layer, a conductive layer and a surface protective layer on a cylindrical translucent conductive support. A photothermographic recording medium, a light irradiation unit arranged inside the photothermographic recording unit for irradiating pulsed light, and a light irradiation unit arranged outside the photothermographic recording unit so as to face the light irradiation unit. Toner supply means for supplying heat fixing toner to the outer peripheral surface of the recording body, pressure transfer means for pressing the recording paper against the outer peripheral surface of the light-sensitive recording body, and cooling for lowering the temperature of the outer peripheral surface of the light-sensitive recording body. And means.

[0027]

In the image forming apparatus of the present invention, since the photothermographic recording body having the above-mentioned configuration is used, it is not necessary to separately form and arrange the heating elements like a thermal head, and it is possible to form a fine electrode pattern or drive the division. A large number of IC chips are also unnecessary. Therefore, the structure of the recording medium is simplified, and the recording power can be supplied from one power source at a time, so that the structure can be simplified.

In the recording section of the image forming apparatus of the present invention, in which the recording medium is irradiated with light to generate heat to perform heat-sensitive recording, in the main scanning direction, light irradiation based on recorded information can be performed line by line. Therefore, it is possible to simultaneously record one line in the main scanning direction. On the other hand, the recording in the sub-scanning direction is performed by sequentially moving the heat generating portion as the cylindrical recording body rotates, so that it is possible to sufficiently wait for the heat generating portion to cool. Therefore, the recording speed in thermal recording can be made extremely high. The recording body rotates with the movement of the recording paper, and the recording medium and the recording medium do not rub against each other, so that the recording body is hardly worn and a stable recorded image can be obtained for a long period of time. In addition, the recording medium uses a photoconductive layer of amorphous silicon that has a long service life and excellent stability, and a surface protective layer is also formed, resulting in a much more durable image than the conventional thermal recording system. It becomes a forming device.

Further, when a material having a small thermal conductivity such as glass is used for the substrate of the photothermographic recording body used in the image forming apparatus of the present invention, the escape of heat in the recording portion in the lateral direction becomes small, It is possible to obtain a recorded image with high resolution according to the light irradiation. In that case, in the conventional thermal head, the heating element after recording is insufficiently cooled and the residual heat is adversely affected, but in the photothermographic recording of the present invention, the surface temperature of the heating portion is
By cooling means after recording or shutting off the applied voltage and during the rotational movement of the recording medium, the temperature is sufficiently lowered, so that the adverse effect of residual heat when printing is repeated can be reduced. Therefore, a high-resolution recorded image can be stably obtained.

Further, in the image forming apparatus of the present invention, it is not necessary to generate heat by the division drive in recording in the main scanning direction, so that the heat generation time of the heat generating portion for recording one line is extended to the recording time of one line. Can be set. Therefore, color development or reaction of the heat-sensitive material or heat melting of the heat-meltable ink or heat-meltable toner can be performed even with a low applied voltage, and heat stress of the heat generating portion can be reduced. Therefore, stable recording can be performed, and the life of the recording body is extended.

In the image forming apparatus of the present invention,
Since it is possible to continue the heat generation of one line due to the light irradiation of one line, that is, the heat generation time of one line can be extended as it is by using the light irradiation pulse of one line as a trigger, the time for heat sensitivity is sufficient. The heat-sensitive material can be colored or reacted even at a low applied voltage, that is, at a low temperature, or the heat-meltable ink or the heat-meltable toner can be heat-melted, and the heat stress of the heat-generating portion can be reduced. Therefore, more stable recording can be performed, the life of the recording body is further extended, and the image forming apparatus has high reliability.

In the conventional thermal head, the surface temperature of the heating element had to be raised to 300 to 450 ° C. by applying a pulse voltage for several milliseconds. On the other hand, in the present invention, a pulse voltage of several milliseconds is used as a trigger, and a long heating time of several tens of milliseconds to several hundreds of milliseconds can be obtained. The thermal recording can be completed at a maximum surface temperature of, for example, about 50 to 180 ° C., which is a temperature close to the melting temperature (melting point) of the ink or the heat-meltable toner.

In the image forming apparatus of the present invention, if the applied power is not cut off to cool the heat generating portion during and after the light irradiation for one line, the heat generating portion may continue to generate heat. This phenomenon occurs because the photoconductive layer is made of a photo-semiconductor material, so that the resistance of the photoconductive layer first becomes low due to the irradiation of light, the current due to the applied voltage flows to generate Joule heat, and the temperature rises, which causes the dark resistance of the photoconductive layer. This is because the current continues to flow even after the light irradiation and heat generation continues because of the decrease. In order to stop this heat generation, the cooling means is forcedly cooled to lower the temperature of the photoconductive layer and restore the original high dark resistance.

If the length of the recording paper is shorter than the perimeter of the photothermographic recording medium, the heat generation part is naturally cooled by radiating heat to the substrate by cutting off the applied power each time the recording paper runs. The next image recording is ready. However, in the case of an image forming apparatus that is required to be downsized, the outer diameter of the photothermographic recording medium becomes smaller, and the length of the recording paper becomes longer than the circumference of the photothermographic recording medium. Is required.

In the image forming apparatus according to the second aspect of the present invention, the ink application means for applying the heat-fusible ink is provided on the outer peripheral surface of the photothermographic recording material, that is, the surface of the surface protective layer.
As a result, the heat-fusible ink is first applied to the surface of the surface protective layer of the photothermographic recording medium by the ink applying means, and once solidified, the light applied to the peripheral pressure body through the recording paper in the recording section. The heat-generating portion of the heat-sensitive recording body melts and transfers and fixes only a necessary portion on the recording paper.

Further, in the image forming apparatus according to the third aspect of the present invention, the ink applying means for applying the hot-melt ink is provided on the surface of the peripheral pressure body. As a result, the heat-fusible ink is first applied to the surface of the peripheral pressure member by the ink applying means, and then the heat generating portion of the light-sensitive recording member in contact with the peripheral pressure member causes the heat-meltable ink to adhere to the surface of the photosensitive member. Transferred by heat fusion. Then, the melt-transferred heat-meltable ink is transferred and fixed on the recording paper as it is in the transfer section of the next process by the pressure transfer means such as the peripheral pressure member or the pressure roller.

Therefore, in any case, the waste of ink is much less than in the case of using the ink film, and the running cost can be remarkably reduced.

In the image forming apparatus according to the fourth aspect of the present invention, when the toner applying means for applying the heat fixing toner is provided on the outer peripheral surface of the photothermographic recording medium, that is, the surface of the surface protective layer, the heat fixing toner is used. Is first applied to the surface of the surface protective layer of the photothermographic recording medium by the toner application means, and then is required by the heat generating part of the photothermographic recording medium in which the peripheral pressure member is in contact with the recording paper in the recording part. Only the different parts are melted and transferred and fixed on the recording paper.

Further, when the toner applying means for applying the heat fixing toner is provided on the surface of the peripheral pressure member, the heat fixing toner is first applied to the surface of the peripheral pressure member by the toner applying means, Then, the peripheral pressure body is heat-fused to the surface of the photothermographic recording medium by the heat generating portion of the photothermographic recording medium in contact with the surface.
Then, the heat-fixed heat-fixable toner is directly transferred and fixed on the recording paper by the pressure transfer means such as the peripheral pressure member or the pressure roller at the transfer portion of the next process.

Further, in the image forming apparatus according to the fifth aspect of the present invention, the heat-fixing toner of the heat-fixing toner is provided on the outer peripheral surface of the photothermographic recording medium, that is, the surface of the surface protective layer so as to face the heat generating portion of the photothermographic recording medium. Arrange the supply means. As a result, the heat-fixing toner is melted only in a necessary portion by the heat-generating portion of the light-sensitive recording material in the recording portion, and is thermally fused to the surface of the light-sensitive recording material. Then, the heat-fixed heat-fixing toner is
In the transfer section of the next process, the pressure is transferred and fixed on the recording paper as it is by the pressure transfer means such as the peripheral pressure member or the pressure roller.

Therefore, in any case, the recording material is less wasted and the running cost can be remarkably reduced. Further, since a heat fixing device as in the conventional electrophotographic system is not required, the apparatus can be downsized, the problem of heat from the fixing device is eliminated, and the power consumption can be reduced.

[0042]

EXAMPLES The image forming apparatus of the present invention will be described in detail below based on examples. 1A and 1B show the configuration of an embodiment of the image forming apparatus according to claim 1 of the present invention. The image forming apparatus 1 shown in FIG. 1 is an example of a light-sensitive recording system using a color-developing thermal method using a thermal recording paper or a transfer thermal method using an ink film and plain paper as the recording paper. FIG. Schematic configuration diagram of the forming apparatus 1, FIG.
(B) is an enlarged view of the main part.

In FIG. 1, reference numeral 2 denotes an amorphous silicon (hereinafter abbreviated as a-Si) -based photoconductive layer 4, a conductive layer 5 and a surface protective layer 6 which are sequentially formed on a cylindrical transparent conductive support 3. 7 is a photothermographic recording material formed by
Is a light irradiating means arranged inside. Reference numeral 8 is a recording paper, and in the present invention, a thermal recording paper, a plain paper on which an ink film is stacked, an OHP sheet, or the like is used. In the same figure, an example in which the ink film 16 is stacked on the plain paper 8 is shown.

Reference numeral 9 denotes a peripheral surface pressing member which is arranged outside the recording member 2 and presses the outer peripheral surface of the recording member 2 in a planar shape.
It is composed of two core rods 9a, 9b of high hardness made of metal or the like, and a belt 9c made of elastic rubber or the like wound around the core rods 9a, 9b. Are arranged.

A power source 10 applies a voltage between the conductive support 3 and the conductive layer 5. This voltage is applied to the recording medium 2
On both ends or one end of the non-image forming part, where the conductive surface of the support 3 is exposed without forming an upper layer from the photoconductive layer 4, and the conductive layer 5 without forming the surface protective layer 6. Is provided and the electrode terminals from the power supply 10 are brought into contact with them. At this time, a rotation introducing mechanism such as a slip ring may be adopted so that the recording body 2 can rotate. Reference numeral 11 denotes an image formed on the recording paper 8 by coloring the thermal recording paper or transferring the ink film 16.

A cooling means 12 is a heat sink in this example.
It is composed of a magnet 13, a magnet 14 and a magnetic brush 15 made of heat conductive magnetic particles such as Ni. The temperature of the surface of the recording body 2 can be lowered by applying the magnetic brush 15 to the surface of the recording body 2 to remove the heat by the heat conductive magnetic particles and let the heat escape to the heat sink 13. As the cooling means 12, other means may be used as long as it meets the purpose of the present invention.

The ink film 16 is formed by forming at least a heat-meltable or sublimable ink layer on a base film, and the peripheral surface pressure member 9 is used to heat-sensitize the ink layer so that the ink layer and the recording paper 8 come into close contact. It is pressed by the recording portion of the recording body 2 and is conveyed together with the recording paper 8 as the recording body 2 and the peripheral surface pressing body 9 rotate.

Reference numeral 17 denotes the irradiation light from the light irradiation means 7.
Reference numeral 18 represents a heat generating portion in which Joule heat is generated when the a-Si photoconductive layer 4 receives the irradiation light 17.

Next, the recording principle of the image forming apparatus 1 will be described with reference to FIG. First, the light irradiating means 7 having a line-shaped light emitting portion along the rotation axis direction is fixed inside the recording body 2, and the recording body 2 is rotated at a constant recording speed. Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 by the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7 to the recording medium. The photoconductive layer 4 is irradiated from the side of the support 3 of 2. In the heat generating portion 18 of the photoconductive layer 4 that has received this light irradiation, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the voltage applied by the power supply 10 flows to generate Joule heat. Therefore, the surface temperature of the recording body 2 rises corresponding to the recorded image.

This surface temperature is 300 times that of the conventional thermal head.
A range of 50 to 180 ° C, which is sufficiently lower than 〜450 ° C, is preferable, and a surface temperature of about 100 ° C is particularly preferable. Within this range, the heat generation of the heat generating portion 18 and the heat radiation to the substrate and the like are balanced, it is easy to control to a constant surface temperature, and it is preferable in that it is easy to handle while ensuring recording quality. For example, if the saturation temperature rise value due to light irradiation alone is around 100 ° C and the light resistance value during light irradiation and the dark resistance value at 100 ° C are almost equal, heat generation and heat radiation after light irradiation are balanced. Maintained at around 100 ° C.

When the surface temperature is higher than 180 ° C., a-S
The generation of heat carriers in the i-based photoconductive layer rapidly increases, the dark resistance value of the photoconductive layer becomes sharply smaller than the light resistance value at the time of light irradiation, and the dark resistance value rapidly increases even when the light irradiation is stopped. There is a tendency that the temperature is lowered and the temperature is further raised, and the photoconductive layer is destroyed. On the other hand, if the surface temperature is lower than 50 ° C, good heat-sensitive recording cannot be performed.

Due to such a lower surface temperature and a longer recording time than the conventional one, color development of the heat-sensitive recording paper or transfer of the heat-meltable or sublimable ink from the ink film 16 is performed, and image formation in the main scanning direction is performed. Be done. further,
By continuously irradiating light corresponding to the recorded image, the recording paper 8 is also conveyed at the same speed as the recording speed according to the rotation of the recording body 2, and image formation in the sub-scanning direction is performed. An image 11 is formed on the recording paper 8. On the other hand, the heat generating portion 18 moves from the position A shown in FIG. 1B to the position B by the rotation of the recording body 2, and thereafter, is cooled by the cooling means 12 of the next process to be in the dark resistance state where the resistance is high again. Since it returns, the current stops flowing and the surface temperature of the recording body 2 drops.

The change in the surface temperature of the recording body 2 in the recording portion of the image forming apparatus 1 of the present invention will be described with reference to the graph of FIG. 2 in comparison with the case of the conventional thermal head. FIG. 2A shows a recording signal (applied voltage pulse) in the conventional thermal head and changes in the surface temperature of the recording portion corresponding thereto, and FIG. 2B shows a recording signal (irradiation) in the photothermographic recording body 2 of the present invention. Optical pulse) and the corresponding change in the surface temperature of the recording section.

In the vertical axis of FIG. 2A, the upper portion corresponds to the voltage E of the applied voltage pulse, and the lower portion corresponds to the surface temperature H of the recording portion. The horizontal axis corresponds to the time T, and shows the elapsed time of the heating element that does not move.

First, when an applied voltage pulse with a voltage of E ₁ for a time T ₁ is applied to the heating element, the surface temperature of the recording portion changes from the reference temperature H ₀ near room temperature to thermal recording during the time T _1. The temperature rises to the temperature H _{1 at which} it takes place. Then, the applied voltage pulse becomes the reference voltage E ₀ , the temperature of the recording portion decreases until the period T ₂ when the recording paper moves and the recording of the next line is performed, and the voltage pulse is applied again and the temperature changes. The recording is repeated by increasing. Where normally H ₁ is
The temperature is about 300 to 450 ° C., T ₁ is about 0.5 to 5 milliseconds, and T ₂ is about several tens of milliseconds.

In the conventional thermal head, for example,
When a 2560-dot heating element is driven in 20 divisions every 128 dots and recording is performed at a recording speed of 20 mm / sec, the voltage pulse application time T ₁ is approximately 2 ms, and the 1-line recording cycle time T ₂ is approximately 40 milliseconds. At this time, if a material having low heat conduction is used for the substrate of the thermal head, the surface temperature of the heat generating portion does not sufficiently decrease during the period T ₂ , and the temperature returns to the reference temperature H ₀ as shown in FIG. 2A. Disappear. This increase in the reference temperature causes deterioration in image quality such as background stains on the non-recording portion and reduction in contrast of the recording portion. Further, as described above, the voltage pulse application time T ₁ and the recording cycle time T ₂ are short, the temperature H ₁ is high, and the same heating element repeats T
_Since it is used in ₂ cycles, the thermal stress on the recording part was also large.

On the other hand, the vertical axis of FIG. 2B shows the intensity L of the irradiation light pulse in the upper part, the resistance value (dot resistance value) R in the recording part in the middle part, and the surface temperature H in the recording part in the lower part. It corresponds. Similarly, the horizontal axis corresponds to the time T, and each of them shows the elapsed time of the heat generating portion that moves with the rotation of the recording body 2.

Also in the photothermographic recording medium 2, when the heat generating portion 18 is irradiated with the irradiation light pulse at the intensity L ₁ for the time T _{3 in} the state where the voltage is applied to the photoconductive layer 4, the photoconduction of the recording portion is performed. The resistance value of the layer decreases from R ₀ to R ₁ , and its surface temperature rises during the time T ₃ from a reference temperature H ₀ near room temperature to a temperature at which thermal recording is started. At this time, the resistance value of the heating portion 18 decreases from R ₁ to R ₂ . Then, even if the irradiation light pulse intensity returns to the reference value L ₀ (normally dark state), the resistance value of the heat generating portion 18 decreases from R ₂ to the dark resistance value R ₃ .
During this time, the surface temperature changes from H ₁ to H ₂ . Cooling means 12
Up to the time T ₄ until the applied power is cut off, the surface temperature of the heat generating portion 18 is maintained at the high temperature H ₁ to H ₂ . The H ₁ to H ₂ are 50 to 180 ° C., and preferably about 100 ° C. among them.

Time T ₅ is the time for thermal recording, and time T _5
6 indicates the cooling time. The heating unit 18 is returned to the surface temperature H ₀ close to the original room temperature by the cooling means 12 arranged on the outer periphery of the recording body 2 during the time T ₆ and further after the standing time T ₇ . The time T ₈ is the time for one rotation of the thermosensitive recording medium 2.

At time T ₃ , T does not have to be divided and driven, so T
_It can be longer than ₁ , and can be set in 0.5 to ₁₀₀ milliseconds.
With the recording speed of the present invention, it is about 1 to 100 milliseconds. Further, the time T ₄ corresponds to the heat carrier generation time,
With the recording speed of the present invention, it is a sufficiently long recording time of about several tens to several hundreds of milliseconds. During the time T ₅ , the recording paper 8 is
It moves closely to the peripheral surface of the photothermographic recording body 2. The time T ₈ is sufficiently long, and at the recording speed of the present invention, several tens of milliseconds to
It takes about a few seconds.

In this way, the heating section 18 of the present invention repeats recording after a sufficiently long time. Furthermore, the heat generating portion of the present invention
18 are continuously distributed over the entire outer circumference of the photothermographic recording body 2, and recording can be continuously performed without interruption.

In the recording medium 2 of the present invention, for example, when recording is performed at a recording speed of 20 mm / sec using the recording medium 2 having an outer diameter of 30 mm, it is not necessary to separately drive the heat generating portion, so that the light pulse is generated. The irradiation time T ₃ becomes as long as about 4 milliseconds, and the recording cycle time T ₈ of the same heating section 18 becomes very long as about 4.7 seconds. Therefore, even if a material having low heat conductivity is used for the substrate, the heat generating portion 18 is not supplied during the waiting time (leaving time) T _7.
The surface temperature of is sufficiently lowered to the reference temperature H ₀ . When the heat conduction of the substrate is small, the heat escape from the heat generating portion to the substrate is small, the temperature rising efficiency is improved, and the heat escape in the lateral direction is small, so that a high-resolution recorded image can be obtained. Further, the cooling efficiency is good, and the recovery to the reference temperature H ₀ is fast. Furthermore, since the light pulse irradiation time T ₃ , the heat carrier generation time T ₄ , and the recording cycle time T ₈ can be set to be long, good thermal recording can be performed with a low applied voltage and a low temperature, and a heat generating portion is applied. The heat stress is reduced, and the recording medium has a long life. Further, since the recording cycle time T ₈ is sufficiently long, it is possible to further shorten T ₈ to speed up the recording.

The irradiation time T ₃ of the irradiation light pulse in the image forming apparatus of the present invention may be set as follows. The recording density in the image forming apparatus of the present invention is usually
240 to 1200 dpi (dots / inch) is used,
On the other hand, the recording dot size is about 100 μm square for 240 dpi and about 20 μm square for 1200 dpi.
The recording speed at this recording density is about 5 to 400 mm / sec (A
Since 4 sheets are set to about 1 to 80 sheets / minute, the minimum recording time for 1 dot is about 50 μs (400 mm at 1200 dpi).
/ Second), the maximum is about 20 milliseconds (5 at 240 dpi)
mm / sec). Therefore, in the image forming apparatus of the present invention, by setting the irradiation time of the light pulse to the photothermographic recording material to 50 microseconds to 20 milliseconds, good image formation in the recording density and recording speed in the above range can be achieved. Can be done.

Generally, the thermal energy required for heat-sensitive recording is about 1 to 15 J / cm ^{2, although} it depends on the recording material. For example, when the recording density is 300 dpi, the recording dot size is about 80 μm square (84.66 μm square), and the recording energy per dot is about 0.06 to 1.0 mJ / dot. For example, if a recording material requiring recording heat energy of 6 J / cm ² is used, the corresponding recording heat energy per dot is about 0.43 mJ / dot.
Recording speed of 20 mm / sec (equivalent to about 4 A4 sheets / min)
Recording time per dot is about 4 milliseconds (4.23 milliseconds). And the recording power is about 0.10W /
Dot. This recording energy is 1 line (about 2560
It is about 1 J per dot), but in normal recording, the printing density is 3 to 5% on average, so the required power is only about 10 W per line on average.

In the image forming apparatus of the present invention, almost the same heat energy for recording is required, but the recording time can be set to be much longer, so that the recording power can be much smaller. Under the above-mentioned recording conditions (20 mm / sec, about 4 A4 sheets / min, 300 dpi), the heat-sensitive time can be set freely long, but if it is set to 1 second, the outer circumference of the light-sensitive recording body 2 is 20 mm ( If the thermal recording is continued over a circumference angle of about 76 degrees, the recording power will be only about 0.4 mW / dot.

This low power consumption has an important meaning.
That is, an a-Si optical semiconductor material having excellent heat resistance has a high electric resistivity (small electric conductivity), and it is generally difficult to obtain a current necessary for Joule heat generation at a low voltage. However, if it is about 0.4 mW / dot, recording at a low voltage can be realized.

For example, if the applied voltage is 20 V, the relational expression W
= V ² / R, the dot resistance value R is 1 MΩ. Here, the film thickness of the photoconductive layer is, for example, 1 μm, and the electric resistivity of the photoconductive layer is ρ (Ω · cm) or σ (Ω · Ω).
cm) ⁻¹ , the relational expression R = ρ × (1 × 10 ⁻⁴ ) / (8
4.6 × 84.6 × 10 ^-8 ), ρ = 1 / σ, R = 1.4 ρ, ρ = 0.71 × 10 ⁺⁶ (Ω · cm), σ = 1.4 × 10 ^-6 (Ω
・ Cm) ^-1 .

This value is a reasonable value for the a-Si photoconductive layer. For example, in a general electrophotographic recording type optical printer, it is used with an exposure energy of about 0.5 to ¹⁰ μJ / cm ² , and if the recording conditions are 0.12 to 0.1 μJ / cm ^2.
It becomes 2.4 mW / cm ² .

Hydrogenated a-containing 5 to 20% of hydrogen (H)
Si has a light conductivity σp of 10 under these conditions.
It changes to the order of ^-6 (Ω · cm) ^-1 . The dark conductivity σd is also known to be on the order of 10 ⁻⁹ (Ω · cm), which is smaller than the bright conductivity σp by 4 to 2 digits, typically about 3 digits.

Further, hydrogenated a-containing 5 to 20% of hydrogen
Si is doped with impurities and has an activation energy Δ
E can be set freely. It is known that the dark conductivity of a semiconductor material follows an active-type relational expression σd = σ ₀ × exp (−ΔE / kT) with respect to temperature. Where Boltzmann constant k
= 8.62 × 10 ^-5 (eV / K), the dark conductivity σd changes from the order of 10 ^-9 (Ωcm) ^-1 by the change of temperature T.
It can be seen that it can be easily changed to the order of 10 ⁻⁶ (Ω · cm) ⁻¹ . For example, the relational expression exp (−ΔE / kT ₀ ) = 10 ⁻³ × exp (−ΔE / k
From (T ₀ + ΔT), if T ₀ = 293K (20 ° C), the temperature rises when ΔE = 0.5eV ΔT = 159 ° C the temperature rises when ΔE = 0.6eV ΔT = 121 ° C the temperature rises when ΔE = 0.7eV Increase ΔT = 98 ° C, and a recording temperature of about 100 ° C is obtained.

Next, each component of the image forming apparatus 1 of the present invention will be described in detail. An example of the structure of the photothermographic recording body 2 is shown in a sectional view in FIG. In FIG. 3A, an a-Si based photoconductive layer 4, a conductive layer 5 and a surface protective layer 6 are sequentially laminated on a translucent conductive support 3 to form a photothermographic recording body 2. There is. The transparent conductive support 3 may be a transparent support 19 on which a transparent conductive layer 20 is formed, as shown in FIG. Further, a heating resistance layer 21 may be provided between the photoconductive layer 4 and the conductive layer 5, as shown in FIG. In addition, the transparent conductive support 3 in this case also has a transparent conductive layer 20 on the transparent support 19 as shown in FIG.
May be formed.

Materials for the translucent conductive support 3 include Pyrex glass, soda glass, borosilicate glass, alumina silicate glass, silicate glass and other glasses, quartz, sapphire, transparent ceramics and other inorganic materials,
In addition, organic resin materials such as polycarbonate, acrylic, fluororesin, polyester, polyethylene terephthalate, vinylon, epoxy, mylar, polyimide, and polyamide are listed. These may be used as a light-transmitting and conductive material by containing a material imparting conductivity inside, or may be used by forming a light-transmitting conductive layer 20 on the surface.

As the translucent conductive support 3, a cylindrical one is used. The size thereof is appropriately set according to the specifications required by the image forming apparatus, but the thickness is set to 0.5 so that the light irradiation means 7 can be arranged inside while securing the mechanical strength.
It is good to set it to -10 mm, preferably 1-5 mm.

The material of the transparent conductive layer 20 is indium.
Tin oxide (ITO), tin oxide, zinc oxide, lead oxide,
There are indium oxide, titanium oxide, cadmium oxide, copper iodide, etc., and they are thinned to a semitransparent level (several nm) A
You may use the metal layer which consists of u, Ni, Al, Cr, Ag, Cu, Pt, Rh etc. These layer formation methods include active reaction vapor deposition method, vacuum vapor deposition method, resistance heating vapor deposition method, electron beam vapor deposition method, laser beam vapor deposition method, ion plating method, RF sputtering method, DC sputtering method, reactive sputtering method, RF magnetron sputtering method, DC magnetron sputtering method, thermal CVD
Method, plasma CVD method, photo CVD method, spray method, coating method, dipping method, hydrolysis (CLD) method, electroless plating method and the like.

The thickness of the translucent conductive layer 20 is 0.005 to 5 μm, preferably 0.05 to 1 μm, considering that it has lower resistance than the photoconductive layer 4 and suppresses thermal diffusion in the film surface direction. It is good to

The a-Si-based photoconductive layer 4 is made of a material having excellent heat resistance such as a-Si-based material, a-SiC or a-SiC.
-SiN, a-SiO, a-SiGe, a-SiCN,
a- such as a-SiNO, a-SiCO, and a-SiCNO
It is preferable to use a Si alloy-based material. This photoconductive layer 4 is
For example, it is formed by a glow discharge decomposition method, various sputtering methods, various vapor deposition methods, an ECR method, a photo CVD method, a catalytic CVD method, a reactive vapor deposition method, a plating method, etc., and hydrogen (H ) Or a halogen element is contained at 1 to 40 atomic%. Further, in order to obtain desired characteristics of the electrical conductivity such as dark conductivity and photoconductivity of the layer 4, or optical bandgap, the periodic table II
Group Ia element (hereinafter abbreviated as IIIa element) or Group Va element (hereinafter abbreviated as Va group element) is contained, or element such as carbon (C), nitrogen (N), oxygen (O) is contained. The above characteristics may be adjusted.

In particular, when a-SiC is used for the photoconductive layer 4, the x value of a-Si _1-x C _x is set within the range of 0 <x ≦ 0.5, preferably 0.05 <x ≦ 0.45. Of course, in this range, the resistance becomes higher than that of the a-Si layer, the recording current can be made small, and the layer thickness of the photoconductive layer 4 can be made thin, which is desirable.

As the Group IIIa element and the Group Va element, B (boron) element and P (phosphorus) element, respectively, have excellent covalent bond properties and can sensitively change semiconductor characteristics, and also have excellent photosensitivity. It is desirable in that it can be obtained. When it is contained together with elements such as C, N and O, the content thereof is preferably 0.1 to 20,000 ppm if it is a group IIIa element, and V
For group a elements, 0.1 to 10,000 ppm is preferable. Also,
When elements such as C, N, and O are not contained or are contained in a trace amount, 0.01 to 2,000 ppm for Group IIIa elements,
If it is a Va group element, it is preferable to contain 0.01 to 1,000 ppm. These elements may be provided with a gradient in the layer thickness direction, in which case the average content of the entire layer should be within the above range.

Further, the photoconductive layer 4 may contain microcrystalline silicon (μc-Si). By including μc-Si, the darkness and photoconductivity of the photoconductive layer 4 can be reduced, and the degree of freedom in designing this layer is increased. μc-Si can be formed by changing the film forming conditions by the same forming method as that of the a-Si material. For example,
In the discharge decomposition method, it can be formed by setting the substrate temperature and the high frequency power to be high and increasing the flow rate of hydrogen as a diluent gas. It is also possible to add the same impurity element as described above.

As other materials for forming the photoconductive layer 4, As ₂ Se ₃ , CdS, Se-Te and various OPCs are used.
Etc.

The thickness of the photoconductive layer 4 may be 0.01 to 100 μm, preferably 0.1 to 10 μm in consideration of the heat storage effect and withstand voltage characteristic of the layer.

On the photoconductive layer 4, the layer 4 having a lower resistance may be laminated with the heating resistance layer 21 having a high resistance. In this case, the photoconductive layer 4 functions as a switching layer for selectively passing a current through the heating resistance layer 21, and Joule heat for heat-sensitive recording is mainly generated in the heating resistance layer 21. By separating the functions in this way, the burden on the photoconductive layer 4 due to heat generation can be reduced.

The heating resistor layer 21 is made of Ni--Cr, T
_{a 2 N, Ta-SiO 2} , Ta-Si, Ta-Si-
C, Cr-Si-O, ZrN, Ta-SiC or the like is used. As the forming method, RF sputtering method, D
There are C sputtering method, reactive sputtering method, RF magnetron sputtering method, DC magnetron sputtering method, and the like, and layers formed by these methods are excellent in adhesiveness and suitable.

The conductive layer 5 has a function of applying a voltage to the photoconductive layer 4. Further, it is preferable that the photoconductive layer 4 has a function of blocking external light which causes a bad operation or a malfunction. This layer 5 contains Cr, Ti, Ni, W, Mo, Cu,
Au, Al, Zn, Ta, Mn, Fe, Ag, Sn, S
A thin metal layer of b, Co, or the like is used, and the forming method is RF.
Sputtering method, DC sputtering method, reactive sputtering method, RF magnetron sputtering method, D
There are C magnetron sputtering method and the like, and layers formed by these methods are suitable because of excellent adhesion.

The thickness of the conductive layer 5 is 0.005 to 5 μm, preferably in consideration of having a lower resistance than the photoconductive layer 4, suppressing heat diffusion in the film surface direction, and having a light shielding property. Is preferably 0.05 to 2 μm.

The surface protective layer 6 has a function of enhancing the reliability of the recording body 2 as a layer having high hardness, excellent abrasion resistance, high insulation, and excellent heat resistance, oxidation resistance and environment resistance. Have.
Such materials include Ta ₂ O ₅ , Si ₃ N ₄ , Si
_{C, SiO 2, BN, Al} 2 O 3, Cr 2 O 3, a-S
i _1-x C _x : A (0.2 <x <1, preferably 0.5 ≦ x ≦ 0.
95. A is hydrogen or a halogen element), a-Si
_{1-y M y: A (} 0 <y <0.7 .M nitrogen, an element containing at least one oxygen), a-C: A, a-C 1-z M z:
A (0 <z <0.7) and the like can be mentioned. And as the forming method thereof, RF sputtering method, DC sputtering method, reactive sputtering method, RF magnetron sputtering method, DC magnetron sputtering method, glow discharge decomposition method, various sputtering methods, various vapor deposition methods,
ECR method, photo CVD method, catalytic CVD method, reactive vapor deposition method,
There are plating methods. The surface protection layer 6 may also contain a Group IIIa element or a Group Va element for the purpose of adjusting electrical characteristics for the purpose of preventing static electricity.

The surface protective layer 6 has a thickness of 0.01 to 15 μm, preferably 0.1 to 7 μm. If the thickness is less than this range, the surface protection function cannot be provided, and the control of the layer thickness becomes difficult. On the other hand, when the thickness is larger than this range, the heat diffusion in the film surface direction becomes large, the heat conduction from the heat generating portion 18 to the surface of the recording body 2 is deteriorated, the image resolution is deteriorated, and the image is trailed. It happens.

As the light irradiating means 7, various optical printer heads each having a light emitting element or an exposure control element arranged in a line can be used.
ED printer heads are preferred. In addition to this, an EL printer head, a phosphor dot array, a plasma image bar, a liquid crystal optical shutter array, a PLZT optical shutter array, or the like may be used.

As the recording paper 8, a heat-sensitive recording paper or a recording paper such as a plain paper or an OHP sheet on which a heat-meltable or sublimable ink film 16 is laminated is used. The thermosensitive recording paper has a thermosensitive coloring layer containing a dye-based coloring agent that develops color when the temperature rises, formed as a coat layer on the base paper. A recorded image is formed. Further, the heat-meltable or sublimable ink film 16 has a recording material layer of heat-meltable or sublimable ink containing a pigment or a dye formed on the substrate film, and the temperature from the heat generating portion 18 of the recording body 2 is controlled. Upon reception, the recording agent layer is melted or sublimated and transferred and fixed on the recording paper 8 such as plain paper or OHP sheet to form a recorded image.

As the peripheral surface pressure member 9, in addition to the core rods 9a and 9b and the belt 9c as shown in FIG. 1, a platen roller or the like used in an ordinary thermal recording apparatus can be used. it can. The peripheral surface pressing body 9 preferably has a structure in which a belt 9c made of elastic rubber is arranged around high hardness core rods 9a, 9b made of metal or plastic. A material having heat resistance and abrasion resistance is selected for the belt 9c, and chloroprene rubber, silicone rubber, polyurethane rubber, natural rubber, isoprene rubber, styrene rubber, butadiene rubber, styrene / butadiene rubber, nitrile rubber, chlorosulfone is used. Polyethylene rubber, fluorine rubber, acrylic rubber, polysulfide rubber, butyl rubber, ethylene / propylene rubber, etc. can be used. With the above structure, the recording paper 8 is planarly pressed against the outer peripheral surface of the photothermographic recording body 2, and is arranged outside the recording body 2 so as to face the light irradiation means 7.

According to the image forming apparatus 1 having the above-described configuration, the formation of the recording body 2 does not require the pattern formation such as the thermal head or the formation of the multilayer film, and the driving integrated circuit is also unnecessary. By setting the beam diameter of the irradiation light 17, high resolution of a recorded image can be easily achieved, and a highly reliable, long-life and low-cost image forming apparatus can be provided. Also,
Since the positions of the heat generating portions 18 in the recording portion are dispersed over the entire recording area, the thermal stress on the photoconductive layer 4 is not concentrated and the reliability is improved.
Since the cooling time of the heat generating portion 18 can be made sufficiently long, high speed recording becomes possible. Further, the recording body 2 using the a-Si based photoconductive layer 4 having excellent durability and the abrasion-resistant surface protective layer 6 is rotated in synchronization with the conveyance of the recording paper 8. There is almost no problem of fluctuations in characteristics and abrasion, and stable recorded images can be obtained for a long period of time.

Next, the construction of an embodiment of the image forming apparatus according to claim 2 of the present invention is shown in FIGS. 4 (a) and 4 (b). In the figure, the same members as those in FIG. 1 are designated by the same reference numerals. The image forming apparatus 22 shown in FIG. 4 is an example of a photo-thermosensitive recording system using a transfer-type thermal that applies a heat-melting ink to the surface of a recording medium and transfers the heat-melting ink to a recording paper such as plain paper. 4A is a schematic configuration diagram of the image forming apparatus 22, and FIG. 4B is an enlarged view of a main part thereof.

In FIG. 4, reference numeral 2 is a light-sensitive recording material, 7 is a light irradiation means, 8 is a recording paper such as plain paper or an OHP sheet, and 9 is arranged outside the recording material 2 via the recording paper 8. It is a peripheral pressure body. 10 is a conductive support 3 and a conductive layer 5
Is a power source for applying a voltage between and, and this voltage application may be performed in the same manner as in the image forming apparatus 1.

Reference numeral 12 is a cooling means, and reference numeral 23 is an ink application means for forming an ink layer 24 of a heat-meltable ink on the surface protective layer 6 of the recording body 2. As shown in FIG. 4A, the ink applying means 23, the peripheral pressure body 9 and the cooling means 12 are sequentially arranged according to the rotating direction of the recording body 2, that is, in the rotating circumferential direction. A heat-meltable ink 26 is stored inside an ink tank 25 which also serves as a container of the coating means 23. A heater 27 that heats the ink 26 is arranged below the ink tank 25, while a heat roller 28 is arranged above the ink tank 25 so that the lower portion is immersed in the ink 26 and the upper portion contacts the recording medium 2. It is distributed.

Reference numeral 11 represents a recorded image formed by transferring the ink layer 24 on the recording paper 8, and 29 represents the recording body 2 without being transferred.
The residual ink layer remaining on top is shown. Reference numeral 30 is an applied voltage control means for monitoring the surface temperature of the recording body 2 and adjusting the applied voltage from the power source 10 based on the result, but this is not always necessary.

FIG. 4B shows a main part where the recorded image 11 is formed by transferring and fixing a part of the heat-meltable ink layer 24 onto the recording paper 8. In the recording portion of the recording body 2 on which the ink layer 24 is formed, so as to be in close contact with the ink layer 24,
The recording paper 8 is pressed by the peripheral pressure body 9, and the recording paper 8 is conveyed as the recording body 2 and the peripheral pressure body 9 rotate. The core rods 9a and 9b of the peripheral pressure body 9 and the belt 9c,
The irradiation light 17 from the light irradiation means 7 and the heat generating portion 18 are the same as those in FIG.

According to the image forming apparatus 22 of FIG. 4, first, the light irradiation means 7 is fixed inside the recording body 2 and the recording body 2 is rotated at a constant recording speed. Then, the ink applying means 23
As a result, the heat-meltable ink 26 heated and melted by the heater 27 in the ink tank 25 is sucked up by the heat roller 28 and applied onto the surface of the recording body 2. Then, the applied ink immediately cools and solidifies to form a uniform heat-meltable ink layer.
24 are formed.

Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 from the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7. ,
The photoconductive layer 4 is irradiated with light from the support 3 side of the recording body 2. In the heat generating portion 18 of the photoconductive layer 4 that has received this light irradiation, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the applied voltage flows to generate Joule heat. The surface temperature of No. 2 rises corresponding to the recorded image. Due to this temperature rise, the ink in the ink layer 24 is melted by heat, transferred and fixed to the recording paper 8 pressed by the peripheral pressure member 9, and image formation in the main scanning direction is performed. Then, by continuously irradiating the light corresponding to the recorded image, the image formation in the sub-scanning direction is performed according to the rotation of the recording body 2. As a result, the image 11 is formed on the recording paper 8. It

On the other hand, the heat generating portion 18 is sequentially moved by the rotation of the recording body 2 and returns to the dark resistance state of high resistance again by the cooling means 12 of the next process, so that no current flows and the surface temperature of the recording body 2 gradually increases. Goes down.

The residual ink layer 29 left on the recording medium 2 without being transferred is returned to the ink applying means 23 by the rotation of the recording medium 2 and is scraped off by the heat roller 28 to be collected in the ink tank 25 and regenerated. used. The residual ink layer 29 may be collected by a collecting means (not shown) such as a cleaning blade separately provided in the ink applying means 23.

The construction of an embodiment of the image forming apparatus according to claim 3 of the present invention is shown in FIGS. 5 (a) and 5 (b).
Note that, also in this figure, the same members as those in FIGS. 1 and 4 are denoted by the same reference numerals. The image forming apparatus 31 shown in FIG. 5 fuses the heat-melting ink applied to the surface of the peripheral pressure body to the surface of the surface protective layer of the photothermographic recording medium, and then applies the heat-melting ink to plain paper or the like. FIG. 5A shows an example of a light-sensitive recording method using a transfer type thermal transfer method for transferring to a recording paper.
5B is an enlarged view of the main part of FIG.

In FIG. 5, reference numeral 2 is a light-sensitive recording material, 7 is a light irradiating means, 8 is a recording paper such as plain paper or an OHP sheet, and 9 is a peripheral surface pressure member arranged outside the recording material 2. . Reference numeral 10 denotes a power source that applies a voltage between the conductive support 3 and the conductive layer 5, and this voltage application may be performed in the same manner as in the image forming apparatus 1. Reference numeral 12 is a cooling means, and 32 is an ink application means for forming an ink layer 33 of the heat-fusible ink on the surface of the peripheral pressure body 9. The ink applying means 32 and the peripheral pressure body 9
As shown in FIG. 5A, the ink layer 33 is arranged so as to supply the ink layer 33 to the surface of the surface protective layer 6 of the recording body 2 in accordance with the rotation of the peripheral pressure body 9. The heat-meltable ink stored in the coating means 32 is pressed against the surface of the belt 9c of the peripheral pressure member 9, and a heater 34 for heating the ink is arranged inside the belt 9c. Also, 35 is the recording body 2
A molten ink layer formed by melting and transferring the ink layer 33 is shown above, and 36 is a pressure roller as a pressure transfer means for pressing the recording paper 8 against the surface of the recording body 2 and transferring the molten ink layer 35, Reference numeral 11 denotes a recorded image formed by being transferred onto the recording paper 8. In addition to the pressure roller 36, the peripheral pressure body 9 may be used as the pressure transfer means.

FIG. 5B shows a main portion on which the recorded image 11 is formed by sequentially transferring and fixing a part of the heat-meltable ink layer 33 onto the recording body 2 and the recording paper 8. On the surface of the belt 9c of the peripheral pressure member 9, ink applying means 32 and a heater are provided.
The ink layer 33 is formed by 34. The ink applying unit 32 may be a rod-shaped body made of heat-meltable ink. The ink layer 33 is brought into close contact with the recording portion of the recording body 2 by the peripheral pressure member 9, and the heat from the heat generating portion 18 which receives the irradiation light 17 of the light irradiating means 7 causes the surface protection layer of the recording body 2 according to the image information. 6 is melt-transferred onto the surface 6 to form a melted ink layer 35. Next, in the transfer portion, the recording paper 8 is pressed by the pressure roller 36 so as to come into close contact with the ink layer 35, and the recording paper 8 is conveyed as the recording body 2 and the pressure roller 36 rotate. .

According to the image forming apparatus 31 of FIG. 5, first, the light irradiation means 7 is fixed inside the recording body 2 and the recording body 2 is rotated at a constant recording speed. Then, the ink applying means 32
The heater 34 applies the heat-meltable ink to the surface of the belt 9c of the peripheral pressure member 9. Then, the applied ink is immediately cooled and solidified to form a uniform heat-meltable ink layer 33. Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 by the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7.
The photoconductive layer 4 is irradiated with light from the support 3 side of the recording body 2. In the heat generating portion 18 of the photoconductive layer 4 that has received this light irradiation, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the applied voltage flows to generate Joule heat. The surface temperature of No. 2 rises corresponding to the recorded image. Then, due to this temperature rise, the peripheral pressure body 9 causes the recording medium 2
The ink of the ink layer 33 pressed against the outer peripheral surface of the
Transfer and fusion are performed on the recording body 2, and image formation in the main scanning direction is performed. Further, by continuously irradiating light corresponding to the recorded image, image formation in the sub-scanning direction is performed, and as a result, the ink layer 35 corresponding to the image is formed on the recording body 2. The ink layer 35 is sequentially moved by the rotation of the recording body 2 while being melted on the heat generating portion 18, and is transferred onto the recording paper 8 by the pressure roller 36 at the transfer portion. Further, since the recording body 2 is returned to the dark resistance state where the resistance is high again by the cooling means 12 in the next process, the current of the heat generating portion 18 stops flowing and the surface temperature of the recording body 2 is gradually lowered.

On the other hand, the residual ink layer 37 left on the peripheral pressure member 9 without being transferred is returned to the ink applying means 32 by the rotation of the peripheral pressure member 9 and re-melted by the heater 34 so that the ink It is collected by the coating means 32 and reused. Here, the ink may be collected by a collecting means (not shown) such as a cleaning blade separately provided in the ink applying means 32, and may be reused or discarded.

The main components of the image forming apparatuses 22 and 31 are the same as those of the image forming apparatus 1. The main differences will be described in detail below.

The hot-melt ink 26 in the ink applying means 23 or 32 is a mixture of a binder composed of wax and / or a thermoplastic resin, a colorant such as a pigment or a dye, and various additives.

Examples of such waxes include natural waxes such as beeswax, carnauba wax, montan wax, paraffin wax, and microcrystalline wax, or montan wax derivatives, paraffin wax derivatives, alcohol fatty acid esters, chlorinated paraffin,
There are synthetic waxes such as oxidized wax. On the other hand, the thermoplastic resin includes low molecular weight polyethylene, polyvinyl stearate, polystyrene, acrylic resin, polyamide,
Vinyl chloride / vinyl acetate copolymer resins, various petroleum resins, chlorinated rubber, ethyl cellulose, cellulose derivative ionomer resins and the like. These binders occupy 60 to 80% by weight of the ink component and affect the thermal melting characteristics of the ink, so the target melting point, melt viscosity characteristics, shear stress, cohesive force, adhesion to recording paper, heat of fusion, It is appropriately selected according to physical properties such as thermal conductivity.

As the pigment, for example, inorganic pigments such as calcium carbonate, calcined kaolin and amorphous silica, and organic pigments such as urea formalin filler and polyethylene filler are used. As the dye, for example, a monoazo dye, an azomethine dye, a xanthene dye, an anthraquinone dye, thioindigo, or the like is used. Further, carbon black such as furnace black and channel black is used as the black colorant. By selecting these appropriately, inks for black images or color images for red, magenta, yellow, cyan, etc. can be obtained.

The temperature characteristic of the hot-melt ink 26 is 60 to 200.
It is set so as to be in a molten state at 80 ° C, preferably 80 to 150 ° C, and to be solidified at around room temperature. With this characteristic, the ink is melted when heated by the heaters 27 and 34 by the ink applying means 23 and 32 and when receiving the Joule heat from the recording medium 2 in the recording portion, and the ink layers 24 or 33 and 35 are formed. Time,
Further, after the recorded image 11 is formed, it is stable and suitable for the image forming apparatus of the present invention.

The heating of the hot-melt ink 26 in the ink applying means 23, 32 is performed efficiently not only by the heater 27 provided in the ink tank 25 but also by the heater built in the heat roller 28 or the heater 34. Can be heated
The molten state of the ink layers 24 and 33 can be stably maintained.

The thickness of the ink layers 24 and 33 is 0.5 to 20 μm,
It is preferable to set it in the range of 2 to 8 μm. Within this range, a desired recording density can be stably obtained, and at the same time, on the surface of the recording body 2 or the peripheral pressure body 9, Solidification and melting, transfer to recording paper 8, fixing, residual ink layer 29, 37
Can be efficiently collected.

As the surface protective layer 6 of the photothermographic recording body 2 used in the image forming apparatuses 22 and 31, the same material as in the image forming apparatus 1 can be used, but in addition, a resin material excellent in heat resistance is used. You may use. As such a resin, a high heat resistant resin such as a polyimide resin or a polyamide resin is preferable. Also, P
TFE (polytetrafluoroethylene), PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), FEP (tetrafluoroethylene / hexafluoropropylene copolymer), PVDF (polyvinylidene fluorolide), ETFE (tetrafluoroethylene) A fluororesin such as ethylene copolymer), PCTFE (polychlorotrifluoroethylene), etc., and a sliding resin such as POM (polyacetal), styrene, olefin, polyamide or the like are also preferable. Further, a thermosetting resin such as silicone, urethane, epoxy, or phenol, or a heat-resistant thermoplastic resin such as polycarbonate, polyester, polypropylene, methacryl, ABS resin, or elastomer may be used. The surface protective layer 6 using these resin materials has good separability of the heat-meltable ink, and thereby a good recorded image can be obtained.

Surface protective layer 6 in image forming apparatus 22, 31
Has a thickness of 0.01 to 25 μm, preferably 0.1 to 15 μm. If the thickness is less than this range, the surface protection function cannot be provided, and the control of the layer thickness becomes difficult. on the other hand,
If the thickness is larger than this range, the heat diffusion in the film surface direction becomes large, the heat conduction from the heat generating portion 18 to the surface of the recording body 2 is deteriorated, the image resolution is deteriorated, and the image density is insufficient. To do.

The conductive layer 5 has a high hardness and a relatively lipophilic conductive metal material (Cr, Ti,
When Ni, Mo, W, Au, Ta, etc.) is used, the surface protection layer 6 is not always necessary.

The pressure roller 36 as the pressure transfer means has
Transfer rollers used in normal electrophotographic devices,
A platen roller or the like used in a thermal recording type device can be used. These generally have a structure in which an elastic material made of rubber, resin, or the like is arranged around a high-hardness core rod made of metal or plastic. Further, in the image forming apparatus of the present invention, in order to perform transfer and fixing efficiently and reliably, a heating means such as a heater is provided,
The temperature may be raised before use.

According to the image forming apparatuses 22 and 31 as described above, similarly to the image forming apparatus 1, it is possible to easily achieve the high resolution of the recorded image, the reliability is high, the life is long, and the cost is low. An image forming apparatus can be provided. Further, since the thermal stress on the photoconductive layer 4 is not concentrated, the reliability is enhanced, and in addition, the cooling time of the heat generating portion 18 can be made sufficiently long, so that high-speed recording is possible. Furthermore, there is almost no problem of fluctuations in the characteristics of the recording body 2 and abrasion, and a stable recorded image can be obtained over a long period of time. In addition, since the heat-meltable ink layer-formed on the recording body 2 is used for recording an image, it is possible to use plain paper or OHP.
It becomes possible to record a sheet or the like on the recording paper 8.

Next, the constitution of an embodiment of the image forming apparatus according to the fourth aspect of the present invention is shown in FIGS. 6 (a) and 6 (b).
Also in this figure, the same members as those in FIGS. 1, 4, and 5 are denoted by the same reference numerals. Image forming apparatus 38 of FIG.
6A is an example of a photothermographic recording system using a transfer-type thermal method in which a heat-fixing toner is applied to the surface of a recording medium and the heat-fixing toner is transferred to a recording paper. FIG.
Is a schematic configuration diagram of FIG. 6, and FIG. 6B is an enlarged view of a main part thereof.

In FIG. 6, reference numeral 2 is a light-sensitive recording material, 7 is a light irradiating means, 8 is a recording paper such as plain paper or an OHP sheet, and 9 is a circumference arranged outside the recording material 2 via the recording paper 8. It is a surface pressure body. Reference numeral 10 denotes a power source that applies a voltage between the conductive support 3 and the conductive layer 5, and this voltage application may be performed in the same manner as in the image forming apparatus 1. Reference numeral 12 is a cooling means, and 39 is a toner application means for forming a toner layer 40 of a heat fixing toner on the surface protective layer 6 of the recording body 2. The toner applying means 39, the peripheral pressure body 9 and the cooling means 12 are sequentially arranged in the rotational circumferential direction of the photothermographic recording body 2 as in the image forming apparatus 22 according to the second aspect. Toner tank that doubles as a container for coating means 39
A heat-fixing toner 42 is stored inside 41, and a cylindrical conductive sleeve 43 and a magnetic pole roller arranged inside it.
44 and 44 are arranged so as to attract the toner 42, form a magnetic brush, and contact the recording body 2. Also, 11 is the recording paper 8
An image formed by transferring, fusing and fixing the toner layer 40 is shown above, and 45 is a residual toner layer remaining on the recording body 2 without being transferred. Although 30 is an applied voltage control means,
It is not necessary.

In FIG. 6B, a part of the heat fixing toner layer 40 is transferred, melted and fixed on the recording paper 8 to form a recorded image 11
Shows the main part where is formed. The recording paper 8 is pressed against the recording portion of the recording body 2 on which the toner layer 40 is formed by the peripheral pressure body 9 so as to be in close contact with the toner layer 40.
The recording paper 8 is conveyed as the recording body 2 and the peripheral pressure body 9 rotate. The irradiation light 17 from the light irradiation means 7 and the heat generating portion 18 are
These are similar to FIGS. 1, 4, and 5, respectively.

According to the image forming apparatus 38 of FIG. 6, first, the light irradiation means 7 is fixed inside the recording body 2 and the recording body 2 is rotated at a constant recording speed. Then, the toner applying means 39
The heat fixing toner 42 stored in the toner tank 41
Is applied to the surface of the recording body 2 by the sleeve 43 and the magnetic pole roller 44, and a uniform heat fixing toner layer 40 is formed. Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 by the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7 to the recording medium. The photoconductive layer 4 is irradiated from the side of the support 3 of 2. In the heat generating portion 18 of the photoconductive layer 4 which has received the irradiation light 17, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the applied voltage flows to generate Joule heat. The surface temperature of the body 2 rises corresponding to the recorded image. Then, due to this temperature rise, the toner of the toner layer 40 is melted by heat, transferred and fixed to the recording paper 8 pressed by the peripheral pressure member 9, and image formation in the main scanning direction is performed. Further, since the image formation in the sub-scanning direction is performed by continuously irradiating the light corresponding to the recorded image, the image 11 is formed on the recording paper 8.

On the other hand, the heat generating portion 18 is sequentially moved by the rotation of the recording body 2 and moves away from the recording portion, and is cooled by the cooling means 12 to return to the dark resistance state of high resistance again, so that no current flows and the recording body is stopped. The surface temperature of 2 drops. Further, the residual toner layer 45 remaining on the recording body 2 without being transferred is returned to the toner applying means 39 by the rotation of the recording body 2, and is then sleeved.
It is scraped off by 43, collected in the toner tank 41, and reused. Here, the toner may be collected by a collecting means (not shown) such as a cleaning blade separately provided to the toner applying means 39.

The construction of another embodiment of the image forming apparatus according to claim 4 of the present invention is shown in FIGS. 7 (a) and 7 (b). Note that, also in this figure, the same members as those in FIGS. 1 and 4 to 6 are denoted by the same reference numerals. Image forming apparatus of FIG.
46 is a type of photothermographic recording system using a transfer type thermal that fuses the heat-fixing toner applied to the surface of the peripheral pressure member to the surface of the light-sensitive recording medium, and then transfers the heat-fixing toner to the recording paper. This is an example, FIG. 7A is a schematic configuration diagram of the image forming apparatus 46, and FIG. 7B is an enlarged view of a main part thereof.

In FIG. 7, 2 is a thermosensitive recording medium, 7 is a light irradiation means, 8 is a recording paper such as plain paper or an OHP sheet, and 9 is a peripheral surface pressing member arranged outside the recording medium 2. . Reference numeral 10 denotes a power source for applying a voltage between the conductive support 3 and the conductive layer 5, and this voltage application also applies to the image forming apparatus 1, 22,
It may be performed in the same manner as 31 and 38. Reference numeral 12 is a cooling means, and 39 is a toner application means for forming a toner layer 47 of a heat-fixing toner on the surface of the peripheral pressure body 9. This toner applying means 39
As shown in FIG. 7A, the peripheral pressure body 9 and the peripheral pressure body 9 are arranged so as to supply the toner layer 47 to the surface of the surface protective layer 6 of the recording body 2 in accordance with the rotation of the peripheral pressure body 9. . The heat fixing toner inside the coating means 39 is applied to the peripheral pressure member 9 by a sleeve.
Is arranged so as to contact the surface of the belt 9c. Also,
Reference numeral 48 denotes a molten toner formed by melting and transferring the toner layer 47 on the recording body 2 according to the image information from the light irradiating means 7, and 36 denotes a molten toner which presses the recording paper 8 against the surface of the recording body 2. A pressure roller as a pressure transfer means for transferring the layer 48, 11
Indicates a recorded image formed by being transferred onto the recording paper 8. In addition to the pressure roller 36, the peripheral pressure body 9 may also be used for this pressure transfer means.

FIG. 7 (b) shows a main portion on which the recorded image 11 is formed by sequentially transferring and fixing a part of the heat-fixing toner layer 47 onto the recording medium 2 and the recording paper 8. A toner layer 47 is formed on the surface of the belt 9c of the peripheral pressure member 9 by the toner applying means 39. The toner layer 47 is brought into close contact with the recording portion of the recording body 2 by the peripheral pressure body 9, and the surface of the recording body 2 is protected according to the image information by the heat from the heat generating portion 18 which receives the irradiation light 17 of the light irradiation means 7. 6 is melt-transferred onto the surface 6 to form a molten toner layer 48. In the transfer section, the toner layer
The recording sheet 8 is pressed by the pressure roller 36 so as to be in close contact with the recording layer 48, the toner layer 48 is transferred and fixed, and the recording sheet 8 is rotated as the recording body 2 and the pressure roller 36 rotate. Be transported.

According to the image forming apparatus 46 of FIG. 7, first, the light irradiation means 7 is fixed inside the recording body 2 and the recording body 2 is rotated at a constant recording speed. Then, the toner applying means 39
Thus, the heat fixing toner is applied to the surface of the belt 9c of the peripheral pressure member 9 to form a uniform heat fixing toner layer 47. Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 by the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7 to the recording medium. The photoconductive layer 4 is irradiated from the side of the support 3 of 2. In the heat generating portion 18 of the photoconductive layer 4 that has received this light irradiation, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the applied voltage flows to generate Joule heat. The surface temperature of No. 2 rises corresponding to the recorded image. Then, due to this temperature rise, the toner in the toner layer 47 is thermally melted, transferred and fused onto the recording body 2, and image formation in the main scanning direction is performed. Further, by continuously irradiating the light corresponding to the recorded image, the toner layer 47 is also conveyed at the same speed as the recording speed according to the rotation of the recording body 2, and the image formation in the sub-scanning direction is performed. As a result, the molten toner layer 48 corresponding to the image is formed on the recording body 2.

The toner layer 48 is sequentially moved by the rotation of the recording body 2 while being melted on the heat generating portion 18, and is transferred and fixed onto the recording paper 8 by the pressure roller 36 at the transfer portion. Further, since the recording body 2 is returned to the dark resistance state where the resistance is high again by the cooling means 12 in the next process, the current stops flowing and the surface temperature of the recording body 2 is gradually lowered.

The residual toner layer 49 remaining on the peripheral pressure member 9 without being transferred is returned to the toner applying unit 39 by the rotation of the peripheral pressure member 9, and is collected by the sleeve to the toner applying unit 39. And then reused. Here, the toner may be collected by a collecting means (not shown) such as a cleaning blade separately provided in the toner applying means 39, and may be reused or discarded.

Further, the constitution of an embodiment of the image forming apparatus according to the fifth aspect of the present invention is shown in FIGS. 8 (a) and 8 (b). Also in this figure, the same members as those in FIGS. 1 and 4 to 7 are denoted by the same reference numerals. Image forming apparatus of FIG.
Reference numeral 50 denotes an example of a photothermographic recording system using a transfer type thermal recording medium in which a magnetic brush made of heat-fixing toner is brought into contact with the surface of the light-sensitive recording medium and the heat-fixing toner is transferred to a recording paper. 8) is a schematic configuration diagram of the image forming apparatus 50, and FIG.
(B) is an enlarged view of the main part.

In FIG. 8, reference numeral 2 is a light-sensitive recording material, 7 is a light irradiation means, 8 is a recording paper such as plain paper or an OHP sheet, 12 is a cooling means, and 36 is a recording material 2 via the recording paper 8. Is a pressure roller disposed outside the. 10 is a power supply for applying a voltage between the conductive support 3 and the conductive layer 5,
This voltage application may be performed in the same manner as in the image forming apparatuses 1, 22, 31, 38, 46. Reference numeral 51 is a toner supply means for supplying heat fixing toner onto the surface protective layer 6 of the recording body 2. The toner supply means 51, the pressure roller 36, and the cooling means 12 are sequentially arranged in the circumferential direction of rotation of the photothermographic recording body 2. A heat-fixing toner 53 is stored inside a toner tank 52 which also serves as a container of the supply means 51, and a cylindrical conductive sleeve 54 and a magnetic pole roller 55 arranged inside the sleeve 53 suck the toner 53. , A magnetic brush is formed to be in contact with the recording body 2.
Reference numeral 56 indicates a molten toner layer formed by melting and transferring toner from a magnetic brush on the recording body 2, and 11 indicates a recorded image formed by transferring, melting and fixing the toner layer 56 on the recording paper 8. Indicates. Reference numeral 57 denotes a residual toner layer that remains on the recording body 2 without being transferred.

In FIG. 8B, a part of the heat fixing toner 53 is melted and transferred from the magnetic brush to the recording body 2 to form a melted toner layer 51, and then the melted toner layer 51 is transferred to the recording paper 8. , A main portion on which the recorded image 11 is fixed and formed. At the transfer portion of the recording body 2 on which the visualized toner layer 51 is formed, the recording paper 8 is pressed by a pressure roller 36 as a pressure transfer means so as to be in close contact with the toner layer 51. The recording paper 8 is conveyed as the body 2 and the pressure roller 36 rotate. The irradiation light 17 from the light irradiation means 7 and the heat generating portion 18 are the same as those in FIGS. 1 and 4 to 7, respectively. In addition to the pressure roller 36, the peripheral pressure body 9 can also be used for this pressure transfer means.

According to the image forming apparatus 50 of FIG. 8, first, the light irradiation means 7 is fixed inside the recording body 2 and the recording body 2 is rotated at a constant recording speed. Then, the toner supply means 51
The heat fixing toner 53 stored in the toner tank 52
Are uniformly supplied to the surface of the recording body 2 as a magnetic brush by the sleeve 54 and the magnetic pole roller 55. Next, while applying a voltage to the photoconductive layer 4 via the conductive support 3 and the conductive layer 5 by the power source 10, the pulsed irradiation light 17 corresponding to the recorded image is emitted from the light irradiation means 7 to the recording medium. The photoconductive layer 4 is irradiated from the side of the support 3 of 2. In the heat generating portion 18 of the photoconductive layer 4 that has received this light irradiation, the dark resistance state with high resistance changes to the bright resistance state with low resistance, and the current due to the applied voltage flows to generate Joule heat. The surface temperature of No. 2 rises corresponding to the recorded image. Then, due to this temperature rise, light irradiation O
After the FF, the high temperature is continued, and a part of the heat fixing toner 53 corresponding to the high temperature is melted by heat, and the toner is melted and transferred to the recording medium 2 to form an image in the main scanning direction. Further, by continuously irradiating light corresponding to the recorded image, image formation in the sub-scanning direction is performed in accordance with the rotation of the recording body 2. As a result, the molten toner layer 56 is formed on the recording body 2. It is formed.

The melted toner layer 56 is sequentially moved by the rotation of the recording body 2 while being melted on the heat generating portion 18, is moved away from the recording portion, and is pressed by the pressure roller 36 at the next transfer portion. 8 is transferred and fixed.

After that, the heat generating portion 18 is cooled by the next cooling means 12 and returns to the dark resistance state where the resistance is high again, so that the current stops flowing and the surface temperature of the recording body 2 drops. The residual toner layer 57 remaining on the recording body 2 without being transferred returns to the toner supply means 51 due to the rotation of the recording body 2, is scraped off by the sleeve 54, is collected in the toner tank 52, and is reused. It Here, the toner may be collected by a collecting means (not shown) such as a cleaning blade separately provided in the toner supply means 51 and discarded.

The main components of the image forming apparatuses 38, 46, 50 are the same as those of the image forming apparatuses 1, 22, 31. The main differences will be described in detail below. Heat fixing toner 42, 53
There are dry type and wet type developers, and in the case of dry type, there are two-component type composed of carrier and toner and one-component type composed of toner only. Two-component developer is used as a carrier.
It uses iron powder of 00 to 300 mesh or iron powder or magnetic powder such as ferrite whose surface is subjected to oxidation treatment or resin coating treatment, and generally uses colored resin powder of insulating fine particles of 10 μm or less as toner. The toner is held by the magnetic brush by the carrier formed on the sleeves 43 and 54 by the magnetic force, and the magnetic brush is brought into contact with the surface of the recording body 2 or the peripheral surface pressing body 9. Then, the toner layers 40 and 47 are formed, or the toners 42 and 53 are supplied.

This toner is a relatively fragile material such as low molecular weight polystyrene, styrene-acrylic copolymer, polyester, rosin-modified maleic acid resin, phenol resin, coumarone resin, various petroleum resins, styrene-butadiene resin, shellac and the like. A low melting point thermoplastic resin that is easily pulverized, a color pigment such as carbon black or phthalocyanine, an oil-soluble dye such as oil black, and an additive such as oleic acid are uniformly dispersed and mixed, and a particle size of 1 is obtained by various methods. ~Ten
It is pulverized to about μm. The triboelectrification property and polarity of this toner are governed by the triboelectrification series, electric resistance and dielectric constant of the binder resin which is the main constituent material, or the pigments, dyes, charge control agents and external additives which are additives. Its electrical resistivity is such that it can maintain a charged charge even under high humidity.
It is preferably 10 ¹² Ω · cm or more. Incidentally, this toner can also be a toner for a black image or a color image for red, magenta, yellow, cyan or the like by appropriately selecting a pigment or a dye.

On the other hand, the one-component type developer generally uses a magnetic toner, and a magnetic brush is formed on the sleeves 43 and 54 only with the toner, and the magnetic brush is formed on the surface of the recording body 2 or the peripheral surface pressing body 9. To form toner layers 40, 47, etc.,
Alternatively, the toner 42, 53 is supplied. This toner is a binder resin consisting of low molecular weight resin such as various natural wax, polyethylene wax, low molecular weight polypropylene, ethylene-vinyl acetate copolymer, magnetic powder such as magnetite and ferrite, and coloring pigments and dyes, various additives. Is uniformly dispersed and mixed, and is pulverized by various methods to have a particle size of about 1 to 10 μm. The charging of the toner is performed by friction with the sleeve, mutual friction, electrostatic induction, or the like. The electric resistivity is adjusted from conductive to insulating (about 10 ³ to 10 ¹⁵ Ω · cm) according to the charging method used.

As the developer, the same toner as that described above is dispersed in a liquid and stored in the toner tanks 41 and 52, and the sleeves 43 and 54 convey the toner to the surface of the recording medium 2 for coating.
It may be a so-called wet type.

These heat-fixing toners 42 and 53 are applied to the surface of the recording body 2 by electrostatic force, magnetic force, charge injection action, van der Waals force, etc. to form toner layers 40, 47 and the like. The thickness and uniformity of the toner layers 40 and 47 are controlled by adjusting the rotational speeds of the recording body 2 and the sleeves 43 and 54, and the thickness is 1 to 20 μm, preferably 2 to 10 μm.
It is preferable to set the range to the range, in which the desired recording density can be stably obtained, and the melting, transfer, fixing, and recovery of the residual toner layers 45, 49, 57 in the recording section can be achieved. Etc. can be performed efficiently.

Toner coating means 39 or toner supply means
At 51, the toners 42 and 53 are held on the sleeves 43 and 54 by the magnetic force of the magnetic pole rollers 44 and 55, and are conveyed to the surface of the recording body 2. For the transportation, the magnetic pole rollers 44 and 55 may be fixed and the sleeves 43 and 54 may be rotated.
It is also possible to fix 54 and rotate the magnetic pole rollers 44 and 55 inside. Further, the residual toner layers 45, 49, 57 that have not been transferred in the transfer portion return to the toner applying means 39 or the toner supplying means 51 by the rotation of the recording body 2, and are scraped by the magnetic brushes of the sleeves 43, 54. It is dropped, recovered by magnetic force, and reused. Alternatively, it may be collected by a separately provided collecting means and discarded.

As the surface protective layer 6 of the photothermographic recording body 2 used in these image forming apparatuses 38, 46 and 50, the same ones as in the image forming apparatuses 1, 22, 31 can be used. The surface protective layer 6 using the above resin material has good separability of the heat-fixing toner, whereby a good recorded image can be obtained.

The thickness of the surface protective layer 6 in the image forming apparatus 38, 46, 50 is also in the range of 0.01 to 25 μm, preferably 0.1 to 15 μm. If the thickness is less than this range, the surface protection function cannot be provided, and the control of the layer thickness becomes difficult. On the other hand, if the thickness is larger than this range, the heat diffusion in the film surface direction becomes large, the heat conduction from the heat generating portion 18 to the surface of the recording body 2 is deteriorated, the image resolution is deteriorated, and the image density is insufficient. It happens.

According to the image forming apparatuses 38, 46 and 50 as described above, similarly to the image forming apparatuses 1, 22 and 31, it is possible to easily achieve high resolution of recorded images, high reliability and long life. so,
Moreover, a low-cost image forming apparatus can be provided. Further, since the thermal stress on the photoconductive layer 4 is not concentrated, the reliability is enhanced, and in addition, the cooling time of the heat generating portion 18 can be made sufficiently long, so that high-speed recording is possible. Furthermore, there is almost no problem of fluctuations in the characteristics of the recording body 2 and abrasion, and a stable recorded image can be obtained over a long period of time. In addition, since the heat-fixing toner layer-formed or heat-fused on the recording body 2 or the peripheral pressure body 9 is used for recording an image, recording on the recording paper 8 such as plain paper or OHP sheet is possible. Furthermore, since the temperature control as in the case of the heat-meltable ink is not necessary, the structure of the apparatus can be simplified, the reliability can be improved, and the running cost can be reduced.

According to the image forming devices 38, 46 and 50,
The toner is fixed on the plain paper at the recording unit or the transfer unit and does not necessarily require a heat fixing device such as that of an ordinary electrophotographic system, which enables downsizing of the device and heat from the fixing device. The problem of is eliminated and the power consumption can be reduced.

Specific examples will be shown below. Example 1 First, a photothermographic recording material was prepared as follows. Boron silicate glass (Pyrex glass) having an outer diameter of 30 mm, a length of 260 mm, and a wall thickness of 1.8 mm is used as a light-transmissive support, and the surface thereof is subjected to an active reaction vapor deposition method to obtain a surface as shown in Table 1.
Under conditions of 0.2 μm thickness of indium tin oxide (I
A transparent conductive layer made of TO) was formed. Next, as a photoconductive layer, a P-type a-Si layer having a film thickness of 0.5 μm and an I-type a-Si layer having a film thickness of 0.5 μm were sequentially deposited under the conditions of Table 2 by the capacitive coupling glow discharge decomposition method. Further, a Cr layer having a thickness of 0.2 μm is deposited as a conductive layer by an electron beam vapor deposition method, and finally, an oxidation resistant SiO ₂ layer having a thickness of 1 μm and a thickness of 1 μm are deposited as a surface protection layer by an RF sputtering method.
m wear resistant Ta ₂ O ₅ layer was sequentially deposited. In this way, the light and heat sensitive recording material A having the structure of FIG. For this recording material A, the dark resistance value of the photoconductive layer,
Further, the bright resistance value at a wavelength of 685 nm and a light energy of 4 μJ / cm ² was measured, and the results are also shown in Table 2.

[0146]

[Table 1]

[0147]

[Table 2]

As the light irradiation means, a recording density of 30 dpi
(Dot / inch), irradiation light beam size about 80 μm square,
Recording width 216 mm, number of dots per line 2560 dots, emission wavelength 685 nm, irradiation light energy 4 μJ / cm ² (light irradiation time per line 4 ms), light amount variation ± 20%
The following LED printer array head miniaturized so that it can be inserted into the recording medium A was used.

The light and heat sensitive recording medium A and the LED printer array head described above were mounted on the image forming apparatus 1 having the structure shown in FIG. 1, and commercially available heat sensitive recording paper was used to obtain a recording speed of 20 mm / sec. Approximately 4 sheets / minute), applied voltage 20V (10
The image was formed under the condition of V / μm). The thermal recording energy at this time was about 0.4 mJ / dot. When the image thus obtained was evaluated, the image density was 0. D. (Optical recording density) 1.3 and enough density, 300
The image was of good image quality with a resolution of dpi.

Image formation was performed under the same conditions using plain paper and a black ink film for thermal transfer recording instead of the thermal recording paper, and the obtained image was evaluated. D. The image was similarly good in image quality showing a resolution of 300 dpi at a sufficient density of 1.1.

Example 2 In this example, a photothermographic recording material was prepared as follows. An outer diameter of 30 mm as a translucent support,
Using a boron silicate glass (Pyrex glass) having a length of 260 mm and a wall thickness of 1.8 mm, an inactive film of 0.2 μm in thickness was formed on the surface by the active reaction vapor deposition method under the conditions shown in Table 1.
A transparent conductive layer made of tin oxide (ITO) was formed. Next, as a photoconductive layer, a P-type a-Si layer having a film thickness of 1 μm and an I-type a-Si layer having a film thickness of 1 μm were sequentially deposited by the capacitive coupling glow discharge decomposition method under the conditions shown in Table 2. Furthermore, as a conductive layer, a film thickness of 0.2 μm was obtained by electron beam evaporation.
m Cr layer was deposited, and finally, as a surface protection layer, by the same capacitive coupling type glow discharge decomposition method as the photoconductive layer, the oxidation resistance, heat resistance and abrasion resistance of the film thickness of 2 μm under the conditions of Table 3 were obtained. , An a-SiC layer having excellent ink separability and toner separability was deposited. In this way, the light and heat sensitive recording material B having the structure of FIG. Regarding the a-SiC layer of this recording body B, Table 3 also shows the measurement results of the dark resistance value.

[0152]

[Table 3]

The same L as in the photothermographic recording material B and [Example 1]
The ED printer array head is mounted on the image forming apparatus 31 having the configuration shown in FIG. 5, the heat-melting ink is put in the ink tank and the temperature is controlled to 150 ° C. A 6 μm hot-melt ink layer was formed.
Then, using a commercially available plain paper as the recording paper, an image was formed at a recording speed of 20 mm / sec and under an applied voltage of 20 V (10 V / μm). The thermal recording energy at this time is about
It was 0.4 mJ / dot. When the image thus obtained was evaluated, the image density was 0. D. The image was of good image quality showing a resolution of 300 dpi at a sufficient density of 1.2.

[Example 3] In this example, the same photo-sensitive recording material B as in [Example 2] and the same LED printer array head as in [Example 1] were mounted on the image forming apparatus 50 having the configuration shown in FIG. Black insulating toner (particle size 7 μm, electrical resistivity 10 ¹⁵ Ω) made of a binder resin containing ferrite and a magnetic carrier (particle size 100 μm, electrical resistivity 10 ¹⁰ Ω · cm) and a binder resin containing carbon black. .Cm) mixed two-component developer is loaded in the toner applying means, and the magnetic pole roller is fixed and the sleeve is rotated to convey the toner to the surface of the recording medium B to form a toner layer having a thickness of 12 μm. . Then, using commercially available plain paper as the recording paper, 20 mm /
An image was formed at a recording speed of 2 seconds under the condition of an applied voltage of 20 V (10 V / μm). The thermal recording energy at this time was about 0.4 mJ / dot. When the image thus obtained was evaluated, the image density was 0. D. The image was of good image quality showing a resolution of 300 dpi at a sufficient density of 1.2.

[Example 4] In this example, when the photothermographic recording material A of [Example 1] was prepared, a photoconductive layer was deposited under the conditions of Table 4, and otherwise the same as in the recording material A. Recording body C
~ G were produced.

[0156]

[Table 4]

These photothermographic recording materials C to G were mounted on the image forming apparatus 1 and images were formed on the thermosensitive recording paper and plain paper in the same manner as in [Example 1]. Then, when the obtained images were evaluated, it was found that the image density was 0. D. The image was of good image quality with a resolution of 300 dpi at a sufficient density of 1.3.

Example 5 In this example, in producing the photothermographic recording material B of [Example 2], a photoconductive layer was deposited under the conditions shown in Table 4, and the other procedure was the same as for the recording material B. Recording body H
~ L were prepared.

These light and heat sensitive recording materials H to L are applied to an image forming apparatus.
31 and the image forming apparatus 50, [Example 2] and [Example 3]
An image was formed on plain paper in the same manner as in. Then, when the obtained images were evaluated, it was found that the image density was 0.
D. It shows a resolution of 300 dpi at a sufficient density of 1.2,
The image had good image quality.

Example 6 In the same manner as in [Example 2] and [Example 5], a photothermographic recording material B,
The heat-fusible ink layer 24 formed on the surface of the recording body 2 by using H to L is attached to the image forming apparatus 22 having the configuration shown in FIG.
Was melted and transferred to form an image on plain paper. Then, when the obtained images were evaluated, it was found that the image density was 0. D. The image was of good image quality showing a resolution of 300 dpi at a sufficient density of 1.2.

Example 7 In the same manner as in [Example 3] and [Example 5], a photothermographic recording material B,
By using H to L, the heat-fixing toner layer 40 formed on the surface of the recording body 2 or the periphery thereof is attached to the image forming apparatus 38 having the structure shown in FIG. 6 and the image forming apparatus 46 having the structure shown in FIG. The heat fixing toner layer 47 formed on the surface of the surface pressing body 9 is melted,
After transfer and fixing, an image was formed on plain paper. Then, when the obtained images were evaluated, it was found that the image density was 0. D. The image was of good image quality showing a resolution of 300 dpi at a sufficient density of 1.2.

[Example 8] In the same manner as in [Example 3] and [Example 5], a photothermographic recording material B,
The toners H to L are mounted on the image forming apparatus 50 having the configuration shown in FIG. 8, the toner fixing means 51 supplies the heat fixing toner 53, and the toner is melted by heat to form the molten toner on the surface of the recording body 2. The layer 56 was transferred, fixed and imaged on plain paper.
Then, when the obtained images were evaluated, it was found that the image density was 0. D. The image was of good image quality showing a resolution of 300 dpi at a sufficient density of 1.2.

Based on the above results, Table 5 shows a comparison result of recording characteristics between the present invention and the conventional image forming apparatus.
Summarized in.

[0164]

[Table 5]

From Table 5, it can be seen that the photothermographic recording type image forming apparatus of the present invention has superior features as compared with the conventional thermosensitive recording type or electrophotographic type image forming apparatus.

[0166]

As described above in detail, according to the image forming apparatus of the present invention, the image recording process is reduced while securing the image quality and the recording speed equivalent to those of the electrophotographic system, thereby making the apparatus compact and low in cost. And the maintenance work is reduced, no ozone is generated and no environmental problems are caused.
An image forming apparatus having excellent image reproducibility and resolution can be provided. Further, compared to the heat-sensitive recording method, the structure of the recording medium is simpler, the recording medium is easy to manufacture and has high reliability, the image resolution is increased, the recording speed is high, and the image forming apparatus with high image quality and long life is provided. We were able to.

Further, according to the image forming apparatus of the present invention, it is possible to provide the image forming apparatus of the photothermographic recording type having a high recording speed, and the photoconductive layer of the recording medium has high hardness and excellent heat resistance. An a-Si-based photoconductive layer is used, and the recording information written as an optical signal is converted into heat by the light irradiation means provided inside the recording body to perform heat-sensitive recording, and high image quality and stable image characteristics are obtained. Thus, it was possible to provide a highly reliable photothermographic image forming apparatus.

In the image forming apparatus using the photothermographic recording material of the present invention, in the production of the photothermographic recording material, it is not necessary to divide the heating elements, form fine electrode patterns, or a large number of IC chips for division driving. Since the structure of the recording medium is simplified and the recording power can be supplied all at once from one power source, the structure can be simplified.

In the recording section of the image forming apparatus of the present invention, since the light irradiation based on the recording information can be performed in the main scanning direction on a line-by-line basis, one line in the main scanning direction can be simultaneously recorded. On the other hand, since the recording in the sub-scanning direction is performed by sequentially moving the heat generating portion as the cylindrical recording body rotates,
There is no need to wait for the heat generating part to cool. Therefore, the recording speed in thermal recording can be made extremely high. Since the recording body rotates with the movement of the recording paper, the recording body wears very little, and the recording body uses an a-Si based photoconductive layer having a long life and excellent stability. Since the protective layer is also formed, the image forming apparatus has excellent durability and can obtain a stable recorded image for a long period of time.

Further, in the image forming apparatus of the present invention, since heat is not generated by the division drive in the recording in the main scanning direction, the heat generation time of the heat generating portion for recording one line is set to be long to the recording time for one line. Because you can
The heat-melting ink or the heat-fixing toner can be melted by heat even at a low applied voltage, and the cooling time of the heat generating portion can be made sufficiently long to enable high-speed recording. Further, since the positions of the heat generating parts in the recording part are dispersedly present on the entire surface of the recording area, heat stress is not concentrated and the number of times of heat stress of the heat generating part can be reduced. Therefore, stable recording can be performed and the life of the recording body is extended.

In the image forming apparatus according to claim 2 or 3 of the present invention in which the heat-melting ink is applied to the surface of the recording body or the peripheral pressure body, the waste of ink is greater than that when an ink film is used. It becomes very small, and the running cost of recording on plain paper can be significantly reduced.

In the image forming apparatus according to the fourth or fifth aspect of the present invention, the recording material corresponding to the heat-melting ink is applied or supplied with the heat fixing toner on the surface of the recording body or the peripheral pressure body. Is very small, the temperature control of the heat-meltable ink is not necessary, and the running cost of plain paper recording can be significantly reduced. In addition, since it does not require a heat fixing device as in the conventional electrophotographic system, the device can be downsized and the problem of heat from the fixing device can be eliminated.
Power consumption can also be reduced.

[Brief description of drawings]

1A and 1B are a schematic configuration diagram showing an embodiment of an image forming apparatus of the present invention and an enlarged view of a main part thereof, respectively.

2 (a) and 2 (b) are graphs showing changes in surface temperature of a recording portion and corresponding recording signals in the conventional thermal recording method and the photothermographic recording method of the present invention.

3 (a) to 3 (d) are cross-sectional views showing the layer structure of the photothermographic recording material of the present invention.

4 (a) and 4 (b) are respectively a schematic configuration diagram and an enlarged view of main parts showing another embodiment of the image forming apparatus of the present invention.

5 (a) and 5 (b) are respectively a schematic configuration diagram and an enlarged view of main parts showing another embodiment of the image forming apparatus of the present invention.

6 (a) and 6 (b) are respectively a schematic configuration diagram showing another embodiment of the image forming apparatus of the present invention and an enlarged view of the main part thereof.

7 (a) and 7 (b) are respectively a schematic configuration diagram showing another embodiment of the image forming apparatus of the present invention and an enlarged view of the main part thereof.

8 (a) and 8 (b) are respectively a schematic configuration diagram and an enlarged view of main parts showing another embodiment of the image forming apparatus of the present invention.

[Explanation of symbols]

 1, 22, 31, 38, 46, 50 ... Image forming apparatus 2 ... Photothermal recording material 3 ... Photoconductive conductive support 4 ... a-Si-based photoconductive layer 5 ... conductive layer 6 ...・ ・ ・ ・ ・ ・ ・ ・ ・ Surface protection layer 7 ・ ・ ・ ・ ・ ・ ・ ・ Light irradiation means 8 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Recording paper 9 ・ ・ ・ ・ ・ ・・ ・ ・ ・ ・ ・ ・ ・ ・ Pressurized body 10 ・ ・ ・ ・ ・ ・ ・ ・ Power supply 11 ・ ・ ・ ・ ・ ・ ・ ・ Recorded image 12 ・ ・・ ・ ・ ・ Cooling means 16 ・ ・ ・ ・ ・ ・ ・ ・ Ink film 23, 32 ・ ・ ・ ・ ・ ・ ・ ・ Ink application means 26 ・ ・ ・・ ・ ・ Heat-melting ink 36 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Pressure transfer means 39 ・ ・ ・ ・ ・ ・ ・ ・ ・ ・ Toner application hand 51 ............. toner supplying means 42, 53 ........... heat fixing toner

Claims (5)

[Claims] 1. A photothermographic recording medium comprising an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer sequentially formed on a cylindrical translucent conductive support, and the inside of the photothermographic recording medium. And a light irradiating means for irradiating pulsed light and an outer surface of the photothermographic recording body, which is arranged so as to face the light irradiating means. An image forming apparatus comprising: a peripheral pressure member that presses the recording paper in a planar shape; and a cooling unit that lowers the temperature of the outer peripheral surface of the photothermographic recording member. 2. A photothermographic recording medium comprising an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer sequentially formed on a cylindrical translucent conductive support, and an inner side of the photothermographic recording medium. And a light irradiating means for irradiating pulsed light and an outer surface of the light and heat sensitive recording body, which is arranged so as to face the light irradiating means, and presses the recording paper planarly on the outer peripheral surface of the light and heat sensitive recording material. An image forming apparatus comprising: a peripheral pressure member, a cooling unit that lowers the temperature of the outer peripheral surface of the photothermographic recording member, and an ink applying unit that applies a heat-melting ink to the outer peripheral surface of the photosensitive recording member. 3. A photothermographic recording medium comprising an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer sequentially formed on a cylindrical translucent conductive support, and an inner side of the photothermographic recording medium. And a light-irradiating means for irradiating pulsed light, and a peripheral surface which is arranged outside the light-sensitive thermal recording medium so as to face the light-irradiating means and presses the outer peripheral surface of the light-sensitive thermal recording medium in a planar manner. A pressure body, an ink application means for applying a heat-melting ink to the surface of the peripheral pressure body, a pressure transfer means for pressing a recording paper on the outer peripheral surface of the photothermographic recording medium, and a photothermographic recording medium. An image forming apparatus having a cooling means for lowering the temperature of the outer peripheral surface of the. 4. The image forming apparatus according to claim 2 or 3, further comprising a toner applying unit for applying a heat fixing toner in place of the ink applying unit for applying the heat fusible ink. Image forming apparatus. 5. A photothermographic recording medium comprising an amorphous silicon photoconductive layer, a conductive layer and a surface protective layer sequentially formed on a cylindrical translucent conductive support, and the inside of the photothermographic recording medium. And a light irradiating means for irradiating pulsed light and an outer surface of the light and heat sensitive recording body, which is arranged to face the light irradiating means, and supplies heat fixing toner to the outer peripheral surface of the light and heat sensitive recording body. An image forming apparatus comprising: a toner supply unit; a pressure transfer unit that presses a recording sheet against the outer peripheral surface of the photothermographic recording member; and a cooling unit that lowers the temperature of the outer peripheral surface of the photosensitive recording member.