JPH1078665A - Image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device capable of obtaining an image of high quality and excellent sensitivity. SOLUTION: The surface of a microcapsule paper 37 carried from a cartridge 67 at a fast speed is previously heated to a fixed temp., to improve sensitivity, by a film heater 64 arranged to face downward in a projecting curved shape, on the surface of a base 47 and having a positive temperature coefficient. When a paper reciprocating path is reversed and the microcapsule paper 37 is carried in an opposite direction, the paper 37 is exposed by an exposure head 20 and then, developed by a developing part, consisting of a point contact ball 46. After that, the paper 37 passes through the place of the film heater 64 at a low speed, so that a microcapsule on the microcapsule paper 37 is hardened to prevent the occurrence of a change in coloring, after that.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of exposing a photosensitive recording medium on which a latent image of image information is formed by exposure to light to expose the image information by development with an image forming light corresponding to the image information. More particularly, the present invention relates to an image forming apparatus that exposes image forming light using a plurality of light emitting elements.

[0002]

2. Description of the Prior Art U.S. Pat.
No. 399209 discloses that a photosensitive layer having microcapsules containing a photosensitive substance in an internal phase is exposed to radiation in an image-like manner, and a uniform rupture force is applied, whereby the microcapsules rupture and the internal phase substance is imaged. Is described. Exposure changes the mechanical strength of the microcapsules to form an exposure latent image, and when pressure is applied, capsules with low mechanical strength (capsules that have not been cured or softened) are destroyed and color materials, etc. Is discharged and development is performed.

[0003] This image forming system is a completely dry system and has a great advantage because it does not depend on a wet developing solution to generate an image. An imaging color former, such as a nearly colorless color former, is usually encapsulated in microcapsules. When the microcapsules are broken, the color-generating substance (color-forming agent) as a coloring material reacts with the developing substance to form a color image.

In the embodiment described in the referenced patent, the microcapsules were exposed to the image, usually through a nip between a pair of cylindrical calendering (glazing) rollers. The microcapsule paper is broken by passing. Usually high pressure and large glazing rollers are used to develop the microcapsule paper. Even with fairly precise metal polishes, the surface is not flat. If one roller simply rests on the other, the surfaces of both rollers are not in contact over their full width. By applying pressure to the rollers, the uneven surface or irregularities of the surface are smoothed and provide a uniform line of contact between the rollers. High pressure and large rollers are required to achieve a microcapsule breaking force distribution over the entire surface of the microcapsule paper. If the forces are not evenly distributed, the microcapsule paper will not develop uniformly and the resulting image will have poor tonal characteristics. As an example of a developing means for solving this inconvenience, there is a technique using a point contact developing ball, as disclosed in Japanese Patent Application Laid-Open No. 62-161153.

An image forming apparatus which exposes such a photosensitive recording medium with image forming light corresponding to image information and develops the same is disclosed in Japanese Patent Application Laid-Open No. Sho 62-231758. An image forming apparatus which selectively leads to a photosensitive recording medium in accordance with
No. 364, an image forming apparatus which scans a plurality of light source lights and guides the light to a photosensitive recording medium;
There is known an image forming apparatus described in Japanese Patent No. 2822 which exposes the same portion a plurality of times via a polygon mirror or the like in a photosensitive recording medium capable of expressing a plurality of colors.

Further, in Japanese Patent Application Laid-Open No. 4-369633, etc., the photosensitive recording medium is subjected to a heat treatment for a fixing action in which the microcapsules are completely cured after exposure and pressure development so that no color change occurs thereafter. It is also known to provide a heat fixing device that performs heat fixing.

[0007]

In recent years, the present applicant has devised and applied for an image forming apparatus of a type using a plurality of light emitting elements in order to expose a photosensitive recording medium with image forming light. In this type of image forming apparatus, a plurality of light emitting elements are fixed to an exposure head which is relatively moved along a photosensitive recording medium, and output light from the light emitting elements is selectively exposed to light by a shielding plate having a mask hole. It is configured to irradiate a recording medium.

In this case, the light energy emitted from the light emitting element causes a polymerization reaction between the polymerization initiator of the microcapsules in the photosensitive recording medium and the photocurable resin, and the mechanical strength of the microcapsules changes. However, the polymerization reaction rate is not so high. Therefore,
Even if a large amount of light energy is applied to the microcapsules in one pixel portion of the photosensitive recording medium at a time, only a part of the light energy can contribute to the polymerization reaction, and the exposure sensitivity cannot be increased. Was.

In order to solve this problem, it has been considered to raise the sensitivity of the photosensitive recording medium by raising the surface of the photosensitive recording medium to an appropriate temperature before exposure. However, the conventional heat fixing device employs a configuration in which a photosensitive recording medium is passed between a heating roller having a built-in heater and a pressing roller. In general, a temperature sensor is provided and ON / OFF control of a power supply is performed by temperature sensing, or temperature control is performed by using a reed switch that is turned ON / OFF by a temperature change. Since the response of the control is delayed, the occurrence of the hunting phenomenon in which the temperature of the heater and thus the temperature of the photosensitive recording medium passing therethrough repeatedly changes up and down with respect to the target temperature cannot be avoided. With such temperature fluctuations, even when the photosensitive recording medium is passed through the heater section to improve the sensitivity of the photosensitive recording medium, a variation occurs in which the sensitivity of one part is high and the sensitivity of the other part is low. However, there is a problem that uniformity of image quality of the photosensitive recording medium cannot be maintained.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and has as its object to provide an image forming apparatus which enables high-sensitivity color development and improves the image quality of a formed output image. And

[0011]

In order to achieve this object, an image forming apparatus according to the present invention carries a microcapsule containing a photosensitive component and a colorant whose intensity changes with respect to light of a predetermined wavelength. Then, a photosensitive recording medium on which a latent image of image information is formed by exposure, an exposure unit for exposing the photosensitive recording medium, and pressurizing the exposed photosensitive recording medium to destroy weak microcapsules, Developing means for developing the latent image by the coloring material flowing out of the broken microcapsules,
At least a part of a transport path of the photosensitive recording medium from the paper supply unit to the exposure unit and a discharge path from the developing unit to the paper discharge unit is a common path. Transport means for transporting the exposed and developed photosensitive recording medium through the common path to the paper discharge section through the common path, and a transport means provided on the common path. A heating means for heating the photosensitive recording medium before exposure by the exposure means, and for heating again after development by the development means.

The invention described in claim 2 is the first invention.
In the image forming apparatus according to the above, from the heating means,
A heating amount control means is provided for controlling the heating amount so that the amount of heat applied to the photosensitive recording medium before exposure is small and the amount of heat applied to the photosensitive recording medium after development is large. Further, according to a third aspect of the present invention, in the image forming apparatus according to the second aspect, the heating amount control unit transports the heating unit on the common path when the transporting unit passes the photosensitive recording medium. The speed is set to a high speed during heating before exposure by the exposure unit, and to a low speed during heating after development by the developing unit.

According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the heating means comprises a film heater having a positive temperature coefficient. It is. The heating means may be made of an insulating synthetic resin film in which conductive particles such as carbon black are dispersed, or a heating element having a positive temperature coefficient may be provided on one surface of the insulating synthetic resin film. The film is bent so that an intermediate portion of the film protrudes, and is fixed to a support substrate at both ends.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic side view showing a first embodiment of a photosensitive pressure-sensitive printer 80 as an image forming apparatus, FIG. 2 is a bottom view of a main part of the photosensitive pressure-sensitive printer 80, and FIG. 5 is a partially cutaway perspective view, FIG. 5 is a cross-sectional view of the exposure head 20, and FIG. The overall configuration of a photosensitive pressure-sensitive printer 80 for exposing and developing a microcapsule paper 37, which will be described in detail later, will be described with reference to FIG.

A light-shielding cartridge 67 is detachably provided on the front surface of a case 81 of the photosensitive pressure-sensitive printer 80, and the unexposed microcapsule paper 37 is accommodated in the cartridge 67 in a stacked state. . The lamination state at this time is set so that a light-transmitting support 31 described later of the microcapsule paper 37 faces upward.

The cartridge 67 is a photosensitive pressure-sensitive printer 80
In a state where the microcapsule paper 37 is set at a predetermined position of the case 81, the microcapsule paper 37 is taken out one by one from a cartridge 67 by a paper feed roller 65 as a paper feed unit. Pulled out to the left. The unexposed microcapsule paper 37 after leaving the cartridge 67 is kept in an unexposed state by the light-shielding cover of the case 81 or the like.

On the left side of the exposure table 66, there is provided a stopper 69 which is a position where the microcapsule paper 37 is sent to and reciprocates there. The printer 80 has a paper transport path P1 for carrying the microcapsule paper 37 from the cartridge 67, and a paper discharge path for branching from the paper transport path P1 to guide the microcapsule paper 37 on which the image has been formed to the paper output tray 63 outside the apparatus. P2 and a sheet reciprocating path P connected to the sheet transport path P1 and reaching the stopper 69 inside the apparatus.
3 is formed.

The carriage 48 having the exposure head 20 and the developing device 45 and a film heater 64 as a heating means described later are connected to the paper reciprocating path P3 as a common path.
Exposure head 20 disposed above and serving as exposure means
A developing device 45 provided with a point contact ball 46 as a developing means is disposed on the right side (paper discharge side). A film heater 64 is disposed on the paper reciprocating path P3 on the right side of the carriage 48. The film reciprocating path P3 reaches the feed roller 68. On the other hand, a feed roller 50a is disposed on the left side of the carriage 48 on the paper reciprocating path P3 in FIG. The feed roller 68 and the feed roller 65
A branching section between the carry-in paper path P1 and the paper discharge path P2 is disposed between the two, and a paper discharge roller 75 is disposed on the paper discharge path P2. Further, a paper path switching plate (not shown) is provided at the branch portion so as to be switchable, and the paper path switching plate (not shown) carries the microcapsule paper 37 into the apparatus by a paper feed roller 65. When the paper path P1 is removed from the carry-in paper path P1,
1 and inserts the microcapsule paper 37 into the paper discharge passage P.
Guide to 2.

The carriage 48 is a microcapsule paper 37
The unexposed microcapsule paper 37 that has exited from the lower portion of the cartridge 67 in a state of being retracted to the side of the transport path (see FIG. 2) is guided by the feed roller 68 and once passes over the exposure table 66. Then, it is fed to the position of the stopper 69. In this case, the surface of the unexposed microcapsule paper 37 is heated to 45 ° C. to
By heating to a constant temperature of about 0 ° C., the sensitivity at the time of subsequent exposure is improved.

FIG. 3 shows the ratio of the sensitivity of the photosensitive recording medium when the microcapsule 37 as the photosensitive recording medium of the embodiment is heated to a predetermined temperature. When the temperature is raised to 50 ° C,
The sensitivity is increased about 1.3 times. As shown in FIG. 4, a film heater 64 bent downward and convexly curved is attached to a plate-like bracket 641 elongated in a direction perpendicular to the horizontal direction with respect to the transport direction (Y direction) of the microcapsule paper 37, The film heater 64 is arranged such that the lower end surface thereof is in contact with the upper surface of the base 47, and is configured to be heated while sliding on the upper surface of the microcapsule paper 37 transferred on the base 47. With this simple configuration, the film heater 64 reliably contacts the microcapsule paper 37, and no non-heated portion is generated.

As shown in FIG. 5, the film heater 64 of the present invention has a positive temperature coefficient (temperature-resistance characteristic in which the electric resistance increases as the temperature increases). A conductive polymer such as carbon black particles is dispersed in a crystalline polymer film such as polyethylene, polypropylene, ethylene-vinyl acetate copolymer, polyethylene terephthalate (PET), etc. Then, it is considered that the volume rapidly expands, the distance between conductive particles such as carbon black particles increases, and the electric resistance value increases.

In the second embodiment of the film heater 64, a conductive film such as carbon black particles is applied by thick-film printing on one surface of a crystalline polymer film as described above in a predetermined pattern shape. A pair of electrode films are applied by thick-film printing on the surface of the layer, and the upper surface is covered with a synthetic resin film or the like as a protective film. The film heater 64 having such a positive temperature coefficient is a self-temperature control type sheet heating element. That is, when a constant voltage is applied by a constant voltage circuit to generate heat by applying a constant voltage from a pair of electrodes at positions apart from the film heater 64 via the conductive particles, as shown in FIG. Since the current increases, the current flowing through the conductive particle portion gradually decreases as the temperature rises, and when the temperature reaches a predetermined temperature, only a small current flows, and the target temperature (70 ° C. in the example) is reduced as shown by the curve C in FIG. You can keep holding. On the other hand, in the temperature control using a thermal relay or the like, as shown by a D curve (dashed line) in FIG.

Therefore, when the microcapsule paper 37 is heated by the film heater 64 having a positive temperature coefficient as compared with the conventional temperature control by a thermal relay or the like, the surface temperature of the microcapsule paper 37 is kept constant,
There is no unevenness in sensitivity. In the embodiment, the unexposed microcapsule paper 37
Is transported in the direction of the paper reciprocating path P3 at a high speed of 40 (mm / sec.), The surface temperature of the microcapsule paper 37 becomes 50 ° C.
(Deviation due to environmental temperature is ± 5 ° C). Also,
The microcapsule paper 37 once stopped at the position of the stopper 69 is returned to the right, and is exposed to light by the exposure head 20 and passes through the developing device 45 to undergo pressure development as described later. Micro capsule paper 3
7 is transferred at a low speed of about 2 (mm / sec.), Microcapsule paper 37 on which development is completed and a color image is developed
By heating the surface temperature of about 80 ℃ ~ 100 ℃,
By completely curing the capsule and enclosing the dye precursor in the capsule, it has the effect of fixing the color development.

As in this embodiment, the film heater 64
The heat generation temperature of the microcapsule paper 37 itself is kept constant, and the amount of heat applied per unit area of the microcapsule paper 37 due to the difference in the transport speed such as increasing or decreasing the transport speed of the microcapsule paper 37 is set to a predetermined value. Therefore, there is an effect that the structure can be simplified and the surface temperature of the microcapsule paper 37 can be controlled evenly as compared with the conventional temperature control.

As described above, the microcapsule paper 37 on which the final color output image is formed after passing through the film heater 64 and receiving the heating action is discharged out of the photosensitive pressure-sensitive printer 80 by the discharge roller 75. . Below the exposure head 20 at the center of the photosensitive pressure-sensitive printer 80, exposure stands 66 are held parallel to each other with a small distance therebetween. Due to this minute distance, the microcapsule paper 37
Have a structure that passes between the exposure head 20 and the exposure table 66. Therefore, as will be described in detail later, by scanning the exposure head 20 in the front and back directions in FIG. 1, a latent image corresponding to the red, green, and blue images is formed in a selective range of the microcapsule paper 37.

Next, the photosensitive recording medium will be described in detail with reference to FIG. FIG. 7 shows a cross-sectional structure of a microcapsule paper 37 as a photosensitive recording medium.
On the surface of the component, a component that develops a color upon contact with a co-reactant as a coloring material (a dye precursor, hereinafter sometimes referred to as a chromogen)
And a microcapsule 32 containing a component (photocurable resin) whose mechanical strength changes (photocuring) upon exposure to light of a predetermined wavelength, and a dye precursor (chromogen) in the microcapsule. Reacting co-reactant (color developer)
33 and a mixed coating layer 34 is formed.
4, a sheet-like support 35 is sequentially laminated.

The microcapsules 32 include three types of different microcapsules, and each microcapsule has:
Includes a colorless dye precursor for color development of one of yellow, magenta, and cyan, a photocurable resin that is sensitive to light of each wavelength of the three primary colors of light, and a polymerization initiator. Have been. Therefore, when the microcapsule paper 37 is exposed to, for example, blue light (light having a wavelength of about 470 nm), the photocurable resin of the microcapsules 32 containing the dye precursor of only yellow is photo-cured and cured.
When pressure is applied to the microcapsule 7, the photocured microcapsules (in this case, yellow) are not destroyed, and the uncured microcapsules (in this case, magenta and cyan) are destroyed, and the magenta and cyan dye precursors become microscopic. It flows out of the capsule and reacts with the developer to form a color, which is mixed to become blue. This blue color is observed through the transparent support 31.

When green light (light having a wavelength of about 525 nm) is exposed on the microcapsule paper 37, the photocurable resin of the microcapsules containing the magenta-only dye precursor is photosensitive-cured, and yellow and yellow by pressure development. The cyan microcapsules 32 are destroyed, and the yellow and cyan dye precursors react with the developer to develop colors, respectively, and become green by color mixing.

Further, when the microcapsule paper 37 is exposed to red light (light having a wavelength of about 650 nm), the photocurable resin of the microcapsules containing the dye precursor of only cyan is photosensitive-cured, and is yellow-developed by pressure development. , Magenta microcapsules are destroyed, and the yellow and magenta dye precursors react with the color developer to develop colors, respectively, and become red by color mixing.

Further, when all the microcapsules are photosensitive-cured by exposure to light, they do not break down even when pressure-developed, so that color development does not occur, and the surface of the sheet-like support 35 is visually observed via the transparent support 31. You can do it.
The color (for example, white) of the surface of the sheet-like support 35 becomes the background color, and a color image is formed only in the portion where the color reaction has occurred. Note that this principle of coloring is referred to as self-coloring. The surface of the light-transmitting support 31 in the microcapsule paper 37 is referred to as a coloring side surface.

In the case of this embodiment, the light-transmitting support 3
Examples of the material 1 include resin films such as PET (polyethylene terephthalate) and polyvinyl chloride.
Examples of the microcapsules 32 include chromogens of triphenylmethane and spiropyran dyes, photocurable resins of acryloyl group-containing compounds such as trimethylolpropane triacrylate, and photopolymerization initiators such as benzophenone and benzoylalkyl ether. ,gelatin,
Known materials such as polyamides, polyvinyl alcohols, polyisocyanate resins and the like encapsulated in polymer walls can be used.

The co-reactant 33 may be related to the composition of the chromogen in the microcapsule 32, but may be an acidic substance, for example, an inorganic oxide such as acid clay, kaolin, acidic zinc, or titanium oxide. A known developer such as a phenol novolak resin or an organic acid can be used. A binder, a filler, a viscosity modifier, and the like are further added to the microcapsules 32 and the co-reactant 33, and the mixture is coated on the light-transmitting support 31 by a coating roller, a spray, a doctor knife, or the like. Is formed.

As the sheet-like support 35, a transparent, translucent or opaque support, for example, paper (cellulose), synthetic paper, a resin film such as polyester or polycarbonate can be used. Next, the image forming region (developing region) and the peripheral region (non-developing region) of the microcapsule paper 37 configured as described above will be described with reference to FIG.

FIG. 8 is a plan view of the microcapsule paper 37. For example, in FIG. 4, along the Y direction, the microcapsule paper 37 is
1 and at least the exposure head 2
Assuming that 0 moves back and forth in the X direction in FIG. 4, the microcapsule paper 37 has an image forming area 39 for displaying a high-quality image, and a peripheral area 40 surrounding the image forming area 39. Are formed. The peripheral area 40 is defined as an area where a high-quality image cannot be formed, such as an image forming area, when an image is printed on a microcapsule paper by a pressure-sensitive photosensitive printer described later.

One method of forming the peripheral region 40 can be realized by exposing only the peripheral region 40 to intense white light in advance at a factory and sufficiently hardening all the microcapsules in the region. . Since the microcapsules pre-cured in this manner are not ruptured even by pressure development, the internal phase (dye precursor) necessary for image development is not released, and this area is the area that should become a white frame on the printer output. Will say.

In place of such preliminary exposure with white light, a simple pattern can be exposed in advance with light of a predetermined wavelength. This peripheral portion can be pressure-developed at the same time when a desired image (high-quality image) is exposed and pressure-developed, or only the peripheral portion can be pressure-developed before exposing the desired image. It is also conceivable that the peripheral portion is formed in the same manner as the developing portion, and pressure development is performed only in the developing region by exposing only the developing region. However, in this method, capsules that can be broken remain in the peripheral area (non-development area), and care must be taken in handling. Therefore, it is preferable that the peripheral region is exposed to white light before the image forming exposure of a desired high-quality image or is exposed to white light after the image forming exposure.

Next, FIG. 9A, FIG. 9B and FIG.
The configuration of the exposure unit of the present invention will be described with reference to FIG. FIG. 9A is a schematic sectional view showing only a main part of the exposure head 20 for exposing the microcapsule paper 37 as a photosensitive recording medium, and FIG. 10 is a bottom view of the exposure head 20, which will be described later. As described above, the exposure head 20 includes a plurality of light emitting elements and the substrate 1 for supporting (fixing) them.

The manufacturing method is as follows. A white polyimide insulating layer 2 is coated on the surface of a flat aluminum substrate 1 with a thickness of 100 μm.
On the surface of the insulating layer 2, an electrode layer 3 having a predetermined plan view land pattern for transmitting an electric signal is formed by printing. The electrode layer 3 is made of 35 μm copper and 5 μm nickel.
m and gold of 0.5 to 1.0 μm. A required number of concave portions 4 are formed at predetermined positions of the electrode layer 3 formed in a predetermined pattern as described above, and each of the concave portions 4 has an LED as a light emitting element.
Is attached.

That is, using a predetermined mold (not shown) in which a projection corresponding to each of the concave portions 4 and a concave portion corresponding to the convex portion 1a as a material release portion are formed on the lower surface side of the concave portion 4. ,
By precisely press-working the substrate 1 by a known fine blanking process, as shown in FIG. In this case, the bottom surface 4a of each concave portion 4 is formed parallel to the surface of the substrate 1, and the inclined side surface 4b is formed so as to spread upward from the bottom surface 4a. Insulating layer 2 on the surface of substrate 1
The electrode layer 3 is also formed in a predetermined pattern along the surface of the concave portion 4. The depth of each recess 4 is determined by an LED 9 described later.
Is formed deeper than the mounting height.

The electrode layer 3 on the bottom surface 4a of the recess 4
A red LED 7, a green LED 8, and a blue LED 9 are provided and fixed to the surface of the substrate with a conductive adhesive 6, respectively. Here, the depths of the recesses 4 are red LED7, green LED8, blue L
Because it is formed slightly deeper than the mounting height of ED9,
The tops of the LEDs 7, 8, and 9 are located below the surface of the substrate 1. This red LED7, green LED8, blue LE
From the top of D9, a bonding wire 10
Electrical connection is made at a predetermined position of the lead pattern 3, and each LED and the bonding wire 10 are sealed with a transparent sealing material 11 so as not to come into contact with air.

As the adhesive 6, a silver paste is used for the red LED 7, and an epoxy resin or the like is used for the green LED 8 and the blue LED 9. This is because the bottom surface of the red LED 7 is one of the electric terminals, so that it is necessary to make an electric connection with the substrate 1 by the conductive adhesive 6, whereas the green L
In the ED 8 and the blue LED 9, since two electric terminals are disposed on the top surface, an insulating and transparent epoxy resin is used for bonding. By using the transparent adhesive 6,
The output light generated inside the green LED 8 and the blue LED 9 and traveling to the bottom surface passes through the transparent adhesive 6 and passes through the bottom surface 4 of the concave portion 4.
Since the light is reflected at a and is emitted again from the top surface, there is an effect that the output light increases.

The red LED 7 is made of AlGa as its basic material.
As is used, and a DDH structure having a high output and known technology can be applied. The center wavelength of the output light is about 650 (nm). There is one electrical terminal on the top and one on the bottom. Green LE
D8 and blue LED 9 are both GaN as the basic material.
Is used. The center wavelengths of the output light are about 525 (nm) and about 470 (nm), respectively. There are two of these electrical terminals on the top and not on the bottom. Each LE
D emits output light in all directions in space by applying a current in a predetermined direction to two electrical terminals. The output light emitted in all directions is
One part goes directly upward in the drawing, and the other part is reflected by the side surface 4b of the concave portion 4 and similarly emitted upward in the drawing.

The bonding wire 10 is made of a gold wire, and is bonded to the top surface of each LED and the lead pattern 3 by heating and ultrasonic waves. The sealing material 11 is formed of a thermosetting resin, and is usually a transparent silicone resin.
JCR or the like is used. Thermal curing conditions are usually 15
The time at 0 ° C. is about one hour. Since general semiconductor materials such as LEDs have a phenomenon in which when exposed to air, their surfaces are subject to the effects of oxidation, moisture absorption, and the like, and their characteristics are rapidly deteriorated, the sealing material 11 is used for the purpose of avoiding this and the bonding wire 10 and the like. The purpose is to prevent destruction by mechanical shock.

Above the substrate 1, a mask 13 as a selection and supply means having a plurality of pinholes 12 is disposed and positioned via a mask holding material 14. The mask holder 14 is mounted and fixed in a boss hole 15 for positioning on the substrate 1, and a positioning groove 14 a for holding a mask is formed on the upper end surface of the mask holder 14. The mask is loaded into the positioning groove 14a, and the mask 13 is fixed integrally with the substrate 1 by fixing means such as bonding or screwing.
In this embodiment, the mask 13 is integrated with the substrate 1 by the sealing material 11.

The mask holding member 14 is a molded product made of a high-precision heat-resistant plastic material, and is used for positioning the mask 13 in three axial directions through the positioning boss holes 15 on the substrate 1. As described above, since the thermosetting resin is used for the sealing material 11, the mask holding material 14 is used by using the thermosetting resin.
When the positioning and the mask 13 are simultaneously positioned and bonded and fixed, the mask holding material 14 can be used even at the curing temperature of the sealing material 11.
It is necessary to use a heat-resistant material so as not to be deformed.

The mask 13 is formed of stainless steel having a thickness of about 0.1 mm, and its outer shape and pinholes 12 are formed.
Are processed by etching. In addition, the surface is blackened by a dipping method, which is a non-reflection treatment of light. Pinhole 12 has a hole diameter of φ0.2m
The diameter of the hole determines the resolution of the light pattern supplied to the microcapsule paper 37 as the photosensitive recording medium. This pinhole 12 is formed opposite to the top of the red LED 7, the green LED 8, and the blue LED 9, respectively.

In this case, in this embodiment, one set of three LEDs 7a, 7b and 7c for red, one set of three LEDs 8a, 8b and 8c for green and three LEDs 9a for blue , 9b, 9c as one set. And
As shown in FIG. 10, with respect to the three LEDs for red, the distance X1 between the LED 7a and the LED 7b and the distance between the LED 7b and the LED 7b in the reciprocating direction of the exposure head 20a (first direction, X direction in FIG. 10). The interval X1 with the LED 7c is arranged at intervals of an integral multiple (for example, 16 times) of one pixel (one dot) of an image formed on the microcapsule paper 37, while the feed direction of the microcapsule paper 37 (first 2 direction (Y direction in FIG. 10), the LED 7a and the LED
The distance Y1 from the LED 7b and the distance Y1 from the LED 7b to the LED 7c are set so as to be shifted from one pixel (one dot) of the image formed on the microcapsule paper 37 by an integer multiple thereof. is there. Three LEDs 8a, 8b, 8c for green and three LEDs 9 for blue
a, 9b, and 9c are also arranged as described above. The interval Y2 between the set of red LEDs 7 and the set of green LEDs 8 in the second direction (Y direction in FIG. 10).
Are arranged 16 dots apart, and the interval Y2 between the set of red LEDs 7 and the set of blue LEDs 9 is also arranged 16 dots apart.

Therefore, the arrangement of the pinholes 12 formed in the mask 13 also matches the arrangement of the LEDs. Then, while the microcapsule paper 37 is fed in the second direction (Y direction in FIG. 10), the exposure head 20a is moved in the first direction (FIG. (X direction 10) at a predetermined speed V. And
By independently modulating and driving each LED according to image information while moving and scanning, a light of a predetermined center wavelength is supplied at a predetermined light power to a predetermined place for a predetermined time, thereby forming a color image. A latent image can be formed.

Next, a method for scanning the surface of the photosensitive recording medium using the exposure head 20 of the present invention will be described with reference to FIGS. FIG. 2 is a bottom view of the photosensitive pressure-sensitive printer including the exposure head 20 according to the present invention. For convenience, the microcapsule paper 37 is shown as a perspective view for explanation of the configuration, and the microcapsule paper 37 is shown.
Are exposed by the exposure head 20 from the back side in the drawing.

As described in detail with reference to FIGS. 2, 9 and 10, the exposure head 20 includes a mask (selection / supply means) 13 having a pinhole 12, a mask holding member 14, and a substrate 1 (not shown). The exposure head 20
Is fixed on the carriage 48 described with reference to FIG. 2, and the carriage 48 is attached along a guide shaft 49 so as to be able to reciprocate left and right in the drawing.

Here, one set of three green LEDs arranged at intervals of X1 = 16 pixels (16 dots) along the reciprocating movement direction (X direction in FIG. 10) of the carriage 48.
8c, 8b, and 8a each represent Y1 = 1 pixel (one dot) in the feed direction of the microcapsule paper 37 (Y direction in FIG. 10).
And a set of three red LEDs 7c and 7b arranged in the same manner along the reciprocating movement direction of the carriage 48 (X direction in FIG. 10) with X1 = 16 pixels (16 dots) apart. , 7a are positions delayed by 12 dots in the feed direction of the microcapsule paper 37 (Y direction in FIG. 10) with respect to the set of green LEDs, and
The distance between the ED 7c and the red LED 7b is also Y direction in FIG.
1 = 1 pixel (1 dot) shifted, red LE
Also between D7b and red LED 7a, Y1 =
They are arranged shifted by one pixel (one dot). Similarly,
Reciprocating direction of the carriage 48 (X direction in FIG. 10)
X1 = a set of three blue LEDs 9c, 9b, 9a arranged at intervals of 16 pixels (16 dots)
Is a position delayed by 12 dots in the feed direction of the microcapsule paper 37 (Y direction in FIG. 10) with respect to the preceding set of red LEDs, and the blue LED 9c and the blue LED
Also, the blue LED 9b and the blue LED 9 are shifted from each other by Y1 = 1 pixel (one dot) in the Y direction in FIG.
Also, it is assumed that Y1 is shifted by one pixel (one dot) in the Y direction in FIG. here,
In FIG. 6, Y2 = 10 pixels, the blue LED 9a and the red LE
The distance from D7a is 12 pixels. This is for each color LE
This is because it is an integral multiple of the number D (three in the embodiment).

On the other hand, the carriage 48 has a point contact ball 46, a ball socket 51, and a ball support 481 to be described later.
The developing unit 45 is fixed, and the mounting position of the exposure head 20 is set upstream of the point contact ball 46 in the feed direction of the microcapsule paper 37. The carriage 48 having the exposure head 20 and the developing device 45 extends along a direction (X direction in FIG. 2) orthogonal to the feed direction of the microcapsule paper 37 in a horizontal plane as shown in FIGS. Guide shafts 49, 49
And is mechanically driven by the servomotor 62, the gear group 61, and the screw shaft 60 to be reciprocated.

FIG. 11 is a graph showing the time change of the moving speed of the carriage 48, and the movement of the carriage will be described with reference to FIG. The carriage 48 is reciprocated in a trapezoidal speed change pattern with a maximum speed V [m / sec.], A scanning cycle T (sec.), And a constant speed time Tc (sec.) By driving the servo motor 62 and the like. .

That is, as shown in FIG.
8 is reciprocated (reciprocating scanning) in the X direction of FIG. 2 at the maximum constant scanning speed ± V (m / sec.). In FIG. 11, the portion inclined with respect to the time axis (horizontal axis) is an acceleration region / deceleration region between the stop at the reciprocating movement end and the maximum constant scanning speed ± V (m / sec.). Is shown.
Further, the time Tc is the distance between the width of the image forming area 39 (X direction) of the microcapsule paper 37 and the carriage 4.
8 is the time required to pass (the time required for the maximum constant scanning speed), and is the reciprocating scanning period T.

Each of the exposure lines (one line along the X direction in FIG. 2) of the microcapsule paper 37 includes one set of the plurality of red LEDs 7, one set of the plurality of green LEDs 8, and the plurality of blue LEDs 9. One set is controlled to be turned on in accordance with image information. In this lighting control, one set of the red LEDs 7c, 7b, 7a and the green LE
D8c, 8b, 8a, one set of blue LEDs 9c, 9b,
Since there is a set of mounting intervals (pinhole intervals) Y1 of 9a, the exposure of one point in the exposure line requires the time required for the scanning movement of the carriage 48 and the time required to feed the microcapsule paper 37 for Y1. Delay time t according to
It is performed in consideration of. If Y1 is a distance corresponding to two dots of the microcapsule paper 37, the same position is exposed by another LED of the same set by repeating the scanning movement of the carriage 48 and the feeding of the microcapsule paper 37 twice. Become.

That is, when Y1 is one dot, focusing on one pixel of the microcapsule paper 37, the one pixel point (exposure point) is white, so that G light, R light and B light are used.
In order to irradiate light, for example, first, the carriage 48
When the pinhole 12 facing the green LED 8c is located at the one pixel point during the movement in the forward direction (at the time of the movement in the X direction of FIG. 10),
After lighting once for t, the carriage 48 is temporarily stopped at the end of the outward path. Next, 1 microcapsule paper 37
After the paper is fed in the Y direction of FIG.
When the carriage 48 moves in the backward direction (at the time of movement in the X 'direction in FIG. 10), the pinhole 1 facing the green LED 8b is moved.
2 is located at the one pixel point, the green LED 8
b is turned on once for a predetermined short time Δt, and the carriage 48
At the end of the return trip. Further, after the microcapsule paper 37 is fed by one dot in the Y direction in FIG. 10, when the carriage 48 moves in the outward direction (at the time of movement in the X direction in FIG. 10), a pinhole facing the green LED 8a is formed. When 12 is located at the one pixel point, the green LED 8a is turned on once for a predetermined short time Δt, and then the carriage 48 is temporarily stopped at the end of the outward path. In this way, as shown in FIG. 12, for one pixel point of interest, every half of the scanning cycle T,
The green LEDs 8c → 8b → 8a are lit for a short time Δt in this order.

Then, after the microcapsule paper 37 is fed in the Y direction in FIG. 10 by 12 dots, when the carriage 48 moves in the backward direction (when it moves in the X ′ direction in FIG. 10), When the red LED 7c is lit once for a predetermined short time Δt when the pinhole 12 facing the red LED 7c is located at the one pixel point of interest,
The carriage 48 is temporarily stopped at the end of the return path. Next, after the microcapsule paper 37 is fed by one dot in the Y direction in FIG. 10, when the carriage 48 moves in the forward direction (at the X direction in FIG. 10), the red LED is
When the pinhole 12 facing the pixel 7b is located at the one pixel point, the red LED 7b is turned on once for a predetermined short time Δt, and then the carriage 48 is temporarily stopped at the end of the outward path. Further, after the microcapsule paper 37 is fed by one dot in the Y direction of FIG. 10, when the carriage 48 moves in the backward direction (at the time of movement in the X direction of FIG. 10), the pinhole facing the red LED 7a is moved. When the LED 12 is located at the one pixel point, the red LED 7a is turned on once for a predetermined short time Δt, and then the carriage 48 is temporarily stopped at the end of the return path. Similarly, blue L
Lighting is repeated every predetermined short time Δt while reciprocating the carriage 48 in the order of ED 9c → 9b → 9a.

As described above, by irradiating the same exposure position (one pixel point) of the microcapsule paper 37 with a plurality of exposures at intervals of time, the sensitivity of color development is improved and the light irradiation energy density is reduced. In addition, the light density of the color can be changed. That is, as illustrated in FIG. 13, the vertical axis represents the cyan optical density, and the horizontal axis represents the total amount of exposure energy density (J / m ² ). In FIG. 13, the solid line A shows the change in the optical color density of cyan when the red LED is irradiated only once, and the dotted line B divides the red LED into three times at a time interval of half the scanning period T. 4 shows the change in the optical color density of cyan when irradiated with light. In FIG. 13, the cyan color optical density is 10% density, that is, D ₁₀ =
In order to obtain 0.42, one light irradiation requires 3.3 (J /
m ² ), it is necessary to give an exposure energy density of 2.2 (J
/ M ² ).

As can be understood from the comparison of FIG.
When the exposure energy density (J / m ² ) is in the range of 0.5 to 3.3, the same cyan color-developing optical density is required in order to develop the same cyan optical density.
It can be seen that a small exposure energy density is required when the light irradiation is divided into three times, but a large exposure energy density is required when the light irradiation is performed once. The reason is that the polymerization reaction rate between the polymerization initiator of the microcapsules 32 and the photo-curable resin in the microcapsule paper 37 due to the light irradiation is not so high, and is more appropriate than inputting a large amount of exposure energy at once. This is because the above-mentioned polymerization reaction is more likely to be promoted when the exposure energy is input little by little in a plurality of times (for example, 2 to 6 times) at the time interval.

In other words, in the present invention, a sufficient color optical density can be obtained even if the output of one LED as a light-emitting element is reduced or the number of LEDs is small. The microcapsule paper 37 is preferably exposed and developed at a constant speed at least in the image forming area 39 thereof. Therefore, the moving distance L (m) at a constant speed corresponding to the minimum speed constant time Tc necessary for exposing and developing the microcapsule paper 37.
Is a range where at least all the pinholes 12 pass through the image forming area (developing area) 39. The constant speed moving distance L (m) can be freely designed depending on the width of the image forming area 39, the arrangement pattern of the pinholes 12, and the maximum speed V (m / sec.). As a numerical example, L = 0.1118 (m) and V = 0.86 (m / sec.), Whereby the entire surface of the microcapsule paper 37 of A6 size can be exposed.

A photosensitive pressure-sensitive printer 80 as shown in FIG.
The electrical configuration of the control circuit (control means) of
The CPU 70 is connected to a connector 74 for inputting RGB image data from an external host computer via an I / O port 73, and is connected to the exposure head (not shown). LED 20, the driving circuit 77 for the driving motor 78 of the holding feed roller 50, the driving circuit 76 for the carriage feeding servo motor 62, the film heater 6
4 is connected to a constant voltage power supply circuit 79.

The ROM 71 has a program for controlling the operation of the entire apparatus, a program for calculating and determining the lighting time and timing of each color LED of the exposure head 20 from input image data, and a program for determining the order of RGB exposure. A program for controlling the driving of the holding and feeding roller 50 to be described later to convey the microcapsule paper 37, similarly controlling the servo motor 62 for carriage feeding in accordance with the sequence of RGB exposure, and reciprocally scanning the carriage. And various programs such as ON / OFF control of the constant voltage power supply circuit 79 are stored, and the CPU 70 operates according to these programs. The RAM 72 stores the number of copies, the enlargement / reduction ratio of the image, the size of the development area of the microcapsule paper 37, and the like set by the operator from an input panel (not shown). The CPU 70 calculates the driving conditions of the servo motor 62 for feeding the carriage according to the size data of the developing area, and
Exposure and pressure development are performed.

The RG of the output image is sent to the photosensitive pressure-sensitive printer 80.
When the B data is sent, the image data is separated into R image data, G image data, and B image data,
2 buffers. Each LED of the exposure head 20 is electrically driven by a drive circuit (not shown) via a flexible harness 487 (see FIG. 2), and is controlled to be turned on and off according to image information.

Next, the light utilization efficiency of the exposure head 20 configured as described above will be described with reference to FIGS. 9 and 14.
This is explained using a numerical example. FIG. 14 shows a schematic sectional structure of a conventional exposure unit 21. The aforementioned exposure head 20
The difference from the above is that no recess is formed in the substrate 1 of the exposure unit 21, and the LEDs 7, 8, and 9 are mounted on the substrate surface.

The output light power from the red LED 7 is 2 mW in total luminous flux when driven by a current of 20 mA at room temperature.
It is. Also, the chip size of the red LED 7 is the outline □ 0.
It is 3mm and height is 0.2mm. Under the same driving conditions, the light power emitted from the pinhole 12 of the mask 13 at a position 1 mm away from the top surface of the chip has no recess 4 of the present invention as shown in FIG. Is mounted, the light utilization efficiency is 3.2%. The light use efficiency of the green LED 8 and the blue LED 9 was almost the same.

On the other hand, in the device provided with the concave portion 4 as shown in FIG. 9, the light power emitted from the pinhole 12 of the mask 13 at a position 1 mm away from the chip top surface under the same conditions is 120 μW. The light utilization efficiency was almost doubled to 6.0%. The effects of the green LED 8 and the blue LED 9 were almost the same. In addition, such light use efficiency can reduce the surface roughness of the side surface 4b,
If b is a reflecting mirror having a free-form surface shape, it can be further raised.

As for stray light which is not necessary for image formation, as shown in FIG. 14, in the exposure section 21 having no concave portion 4, since each LED chip is mounted on a flat substrate, the red LED Output light is directly green LED8,
There is a problem of so-called stray light that the green light is emitted from the pinhole 12 from which the green LED 8 is to be emitted, which is reflected and hits the bonding wire 10 for connecting the green LED 8, and the image quality of the color image output by the image forming apparatus is reduced. There is a problem that it is greatly deteriorated. On the other hand, if the exposure head 20 having the configuration as shown in FIG. 9 is used, there is no problem that the output light of the red LED 7 directly hits the green LED 8 due to the presence of the side surface 4 b of the concave portion 4. Since the antireflection process is performed on the mask 13, light that is not directly emitted from the pinhole 12 is also absorbed by the surface of the mask 13, and there is no deterioration in image quality.

Further, with respect to the length and the bonding height of the bonding wire 10, when the bonding process is performed by a wire bonder (bonding robot), if the exposure head 20 according to the present embodiment is used, the length of the bonding wire 10 is reduced. Since the bonding positions are almost at the same height, it is clear that the effect is large, such as the operation of the bonding robot can be performed in a simple process.

In FIG. 9, the size of the recess 4 is
It is effective to increase the light use efficiency by making the shape as small as possible to enclose each LED chip, but as a means for realizing this, the bonding pads (the connection positions of the wires 10) in the land pattern 3 It is effective to bring it to the site. This is also an effective means because it is difficult to form the land pattern 3 on the bottom surface 4a or the side surface 4b when a small and relatively deep concave portion 4 has to be formed.

Regarding the required energy density of the photosensitive recording material, the required energy density of the microcapsule paper (energy density at which the capsules are photosensitive-cured) described later is as follows.
It is about 3 (J / m ² ). This is the sensitivity example of silver halide photography 0.
1 (J / m ² ), which is about 300 times, and the energy required for exposure of the microcapsule paper is much larger than the energy given to the photosensitive material in ordinary photography or the like.

In order to realize exposure of microcapsule paper using the image forming apparatus of this embodiment, the above-described red LED is used.
7, the power that can be supplied per red LED 7 is 120 to expose a range of 1 m ² in 600 seconds.
Since the power is .mu.W, 42 red LEDs 7 are required according to a simple calculation formula in which the write duty is 100%. On the other hand, in the image forming apparatus without the concave portion 4 as shown in FIG. 9, the number of red LEDs 7 is doubled to 84.

Next, the developing process of the microcapsule paper will be described with reference to FIGS. FIG.
Is an embodiment of the developing device 45 for developing the microcapsule paper 37. Note that the exposed microcapsule paper 37 is not shown for simplicity. The developing device 45 as a pressure developing means is provided with a microcapsule paper 37 by point contact.
The developing process is realized by elastically pressing the surface, and the point contact ball 46 is pressed against the microcapsule paper 37 while the pressing position is changed to perform pressure development only in the developing region. In order to change the pressing position, a relative movement is generated between the point contact ball 46 and the microcapsule paper 37 in parallel with the plane of the microcapsule paper 37. The point contact ball 46 may be moved with respect to the microcapsule paper 37, or the microcapsule paper 37 may be moved with respect to the point contact ball 46.
May be moved, or both the microcapsule paper 37 and the point contact ball 46 may be moved. In order to reduce the size of the apparatus, preferably, the microcapsule paper 37 is reciprocated along one axis in parallel with the microcapsule paper 37 while the microcapsule paper 37 intersects the moving direction of the point contact ball 46, preferably. A method of moving in an orthogonal direction is preferable.

At the point of pressurization by the point contact ball 46, the microcapsules are pressure-developed and destroyed with a small pressing force, and their inclusions (colorless dye precursor) flow out to cause a color-forming reaction with the color developer. Occur. And the point contact ball 46
The color image is visualized in the development area by the relative movement of the microcapsule paper 37 and the microcapsule paper 37. In the embodiment shown in FIG. 16, the microcapsule paper 37 to be pressure-developed is fixed on a substantially flat mounting base 47. The base 47 is formed into a roller shape in addition to the flat surface, and the microcapsule paper 37 is formed.
It is also possible to provide for sending.

At least one point contact ball 46 is arranged so as to elastically press-fit with the microcapsule paper 37, and the point contact reciprocates within a certain range of the mounting base 47 corresponding to the microcapsule paper 7. That is, the microcapsule paper 37 transported from the exposure table by the transport roller 50 is held by the holding feed roller 50 on the mounting base 47. The holding and feeding roller 50 presses a non-development area of the microcapsule paper 37 and is driven to rotate by a feed motor for each development line described later. A pair of left and right sides are provided on both sides of the development area.

A carriage 48 is supported so as to be able to reciprocate along a guide shaft 49 which is parallel to the surface of the base 47 and orthogonal to the direction of feeding the microcapsule paper. A point contact ball 46 is rotatably supported on the base 47 side of the ball support portion 481 of the carriage 48 via a ball socket 51. The ball 46 is formed on the carriage 48 together with the ball socket 51. The sliding hole 482 is housed so as to be slidable vertically in the figure. A step portion 511 is formed at an upper end portion of the socket 51, and the step portion 511 abuts on a stopper portion 483 provided at a lower end of the slide hole 482, thereby preventing the socket 51 from falling off. .

A cover plate 484 for closing the sliding hole 482 at the upper portion is screwed to the upper surface of the ball support portion 481. An adjusting screw 485 is screwed to the cover plate 484. A compression spring 48 as an elastic body is provided between the shaft end of the adjusting screw 485 and the socket 51.
6, the socket 51 is urged by the stopper portion 483. However, before the socket 51 comes into contact with the stopper portion 483, the point contact ball 4
The dimensions of each part are set so that 6 is pressed against the base 47.

Here, the urging force of the point contact ball 46 on the microcapsule paper 37 can be replaced by various types such as a pneumatic device, a hydraulic device or a solenoid instead of using the compression spring 486. It is possible to use not only an elastic body but also an electromagnetic force. Further, instead of biasing the point contact ball, the base side can be biased toward the ball, and both can be biased in directions in which they contact each other. In short, any biasing means between the point contact ball and the base side (microcapsule paper side) may be used.

The carriage 48 has a feed screw 6
The feed screw 60 is connected to the output shaft 621 of the feed servomotor 62 and rotates forward and backward. The forward / reverse rotation of the feed screw 60 causes the carriage 48 to reciprocate in parallel to the base 47, and the reciprocating movement causes the pressure points of the point contact balls 46 to be sequentially changed.

The feed servo motor 62 is capable of controlling the rotation direction and the rotation amount, has an encoder for detecting the drive amount, and is driven and controlled by a control circuit. As this feed motor, a pulse motor of open loop control can be adopted. Although the position confirmation function is eliminated, the cost can be reduced because the drive circuit can be simplified.
In addition to the pulse motor, a general DC / AC motor or the like can be used. The reason why the motor whose drive amount can be controlled is used is to set the reciprocating movement amount of the carriage 48 in accordance with the size of the development area in order to pressurize and develop only the development area of the microcapsule paper 37.

When the carriage 48 is moved along the guide shaft 49 and one line of pressure development is completed, the holding and feeding roller 50 is rotated by one line and
8 is repeated to perform pressure development for one line, and pressure development is performed over the entire development area. 17 and 18 show a second embodiment of the photosensitive pressure-sensitive printer 80, which can be mounted in a tower type CPU case of a personal computer, and which is supplied to the inside of the front opening 100a of the main case 100. The paper unit case 102 is configured to be removably insertable, and a latch (not shown) is turned on by turning a locking clutch knob 103 mounted on each of the front left and right sides of the paper supply unit case 102 in a predetermined direction. The engagement part of the case 100 is disengaged.

On the front face of the paper feeding unit case 102, a cartridge 67 in which microcapsule paper 37 is stacked and housed is detachably mounted. In the paper supply unit case 102, a paper supply roller 65, a paper supply path P5, and a paper discharge path P6 are provided.
And a film feeder 64 for heating the surface (upper surface) of the microcapsule paper 37 on the transport plate 105.

In the main case 100, a lower nip roller 107a, which is fixed at a lower position adjacent to the rear opening 106 of the paper feeding unit case 102, is disposed, and an upper nip roller 17b adjacent to the upper side of the lower nip roller 107a. Is
An actuator (not shown) is configured so as to be able to move toward and away from the lower nip roller 17a. The upper and lower nip rollers 107a and 107b are for pressure development. An exposure table 66 is disposed adjacent to the inner side of the pair of rollers, and a carriage 48 having the same exposure head 20 as in the first embodiment adjacent to the upper surface of the exposure table 66 has guide shafts 49, 49. Are supported so as to be slidable in a direction orthogonal to the feeding direction of the microcapsule paper 37 via the.

In this embodiment, as the microcapsule paper 37 fed from the cartridge 67 is conveyed to the left in FIG. 17, the surface of the microcapsule paper 37 is treated as a pre-exposure work for improving the sensitivity. The film is heated to about 50 ° C. by the film heater 64, but the gap between the upper and lower nip rollers 107a and 107b is widened so that no pressing work is performed. Then, a part of the timing belt 108 disposed in parallel with the axis of the guide shaft 49 is moved to the carriage 48.
The exposure is executed in the same manner as in the first embodiment by driving the timing belt 108 with a servo motor (not shown), and the sheet is sent to the far side of the sheet reciprocating path P3 via the pair of conveying rollers 109.

Microcapsule paper 3 that has been exposed
When the exposure head 20 is temporarily stopped at the stopper position 69 of the paper reciprocating path P3 and is conveyed rightward in FIG. 17, the exposure head 20 is stopped at a position where it is retracted to the side of the conveyance path of the microcapsule paper 37. ing. The upper and lower nip rollers 107a and 107b are closed by a spring with a force of about 300 Kg weight by closing the gap, and press the surface of the microcapsule paper 37 after exposure with a predetermined pressure, while the film heater 64 is pressed. At 80 ° C ~ 100
Heat treatment at a temperature of ° C. to promote color development. The microcapsule paper 37 that has been subjected to the above-described pressure development processing is discharged from the photosensitive pressure-sensitive printer 80 via the discharge roller 75 from the discharge path P6 by the path switching body 104 in the paper supply unit case 102. .

Input data (RGB data, drive control signals, etc.) from the outside such as a personal computer CPU enters the control board 111 through the input port 110a on the rear side of the main case 100, and is transmitted to the photosensitive pressure sensitive printer 80 side. The output data is output from the output port 110b. And RG
The B data is transmitted to the exposure head 20 via the flexible cable 112. Also, the side end portion 113 of FIG.
The microcapsule paper 37 having different widths is brought into contact with the side edge of the microcapsule paper 37 to be conveyed.
Is the reference position of the transfer route.

In this embodiment, the microcapsule paper 37
17 is intermittently moved one dot at a time in the conveying direction of the microcapsules 37 when the microcapsules 37 are conveyed in the left direction in FIG. It will move continuously at a predetermined constant speed. As described in detail above, the printer 80 as the image forming apparatus of the present invention is not limited to the above-described embodiment, but can be variously modified.

The photosensitive recording medium of the present invention is not limited to the above-mentioned microcapsule paper but can be variously modified. As the microcapsule paper, in addition to the above-mentioned self-coloring type, a transfer type can also be used. The transparent base sheet carrying the microcapsules and the developer surface of the image receiving paper carrying the color developing material are superimposed on the microcapsule surface of the base sheet so as to be integrated in a releasable manner. The sheet may be fed from the cartridge on the exposure head side, exposed and developed as it is, discharged outside the apparatus, and then the image receiving sheet may be peeled off. The dye precursor as a color material that has flowed out of the capsule that has been destroyed by pressure is transferred to a color developer of the image receiving paper, and reacts with the color precursor to develop color and become visible.

In place of the dye precursor, a pre-colored pigment or dye may be encapsulated in the microcapsule together with the photosensitive substance. In this case, transfer-type image formation is possible by integrating the image receiving paper (plain paper) without a developer into the base sheet in a releasable manner. This is because the image is exposed on the image receiving paper by peeling. Also,
In addition to microcapsule paper, if the image forming apparatus uses a photosensitive recording medium such as a silver halide film, a diazo type photosensitive paper, etc., which is exposed to light and exposed to light and developed by receiving a developing action, the present invention Since the present invention has the problem, the same effect can be obtained by using the solution of the present invention. Further, it is possible to expose a photosensitive drum for forming an electrostatic latent image used in an electrophotographic color printer.

As the pressure developing means, any of the embodiments in which the microcapsules can be broken under pressure can be employed. Further, the light emitting element is not limited to only the LED,
Various structures such as an L light emitting element, a plasma light emitting element, and a laser light emitting element can be applied. Further, the light emitting element does not need to be made of red, blue and green, and one having various wavelengths can be selected according to the sensitivity characteristics of the photosensitive recording medium. For example, infrared light, red, and green may be selected, or far infrared light, near infrared light, and red may be selected. Ultraviolet rays and far ultraviolet rays are also effective examples of color choices of the light emitting element.

The number of colors of the light-emitting elements is not limited to three colors of red, green and blue, and may be one or two colors, or a general color printer using yellow, magenta, cyan, and black as a coloring agent. And four or more colors can be selected. Further, as the selective supply means, not only a mask which is a thin plate having a pinhole but also an imaging optical system such as a single lens plastic lens as shown in FIG. 19 can be used. That is, the holder 114 mounted in the positioning hole 15 of the substrate 1 faces the concave portion 4 of the substrate and faces the light passage hole 1.
21 is formed, and a lens mounting portion is formed on the peripheral portion of the light passage hole 121, and the single lens plastic lens 1 is formed on the mounting portion.
22, the microcapsule paper 37 is arranged at the focal position of the lens 122. Even if a lens system is used, the light power incident on the lens increases due to the action of the concave portion according to the present invention. As a result, the light power that can be supplied to the photosensitive recording medium increases. The effect that the usage efficiency can be improved remains the same.

[0091]

As is clear from the above description,
An image forming apparatus according to claim 1, which carries a microcapsule containing a photosensitive component and a colorant whose intensity changes with respect to light of a predetermined wavelength, and a photosensitive recording medium on which a latent image of image information is formed by exposure. An exposure means for exposing the photosensitive recording medium, and pressurizing the exposed photosensitive recording medium to destroy the weak microcapsules, and visualizing the latent image by the color material flowing out of the broken microcapsules. An image forming apparatus having a developing unit for causing the photosensitive recording medium to travel from a paper supply unit to the exposure unit and a discharge path from the development unit to a paper discharge unit. Is a common path, and conveys the photosensitive recording medium from the paper supply unit to the exposure unit and the developing unit through the common path, and discharges and develops the exposed and developed photosensitive recording medium through the common path. Transport means for transporting the photosensitive recording medium on the common path and heating the photosensitive recording medium before exposure by the exposure means, and heating the photosensitive recording medium again after development by the development means. Things.

Therefore, by heating the surface of the photosensitive recording medium before exposure to a predetermined temperature in advance, the sensitivity of the photosensitive recording medium after exposure can be improved even if the amount of light energy applied to the photosensitive recording medium during exposure is small. become. In other words,
Even if the light output of each light emitting element in the exposure head is small,
Alternatively, even if the number of light emitting elements provided in the exposure head is small, a remarkable effect that a sufficient coloring optical density can be obtained can be obtained.

Then, by heating the surface of the photosensitive recording medium after development to a predetermined temperature by a heating means, the hardness of the microcapsules in the photosensitive recording medium is sufficiently hardened so that a change in color development does not occur later. Can be fixed. In the present invention,
After exposing the photosensitive recording medium supplied from the paper supply unit of the image forming apparatus in the forward path of the transport path, and then developing it in the return path, or exposing and developing it in the return path of the transport path, The surface of the photosensitive recording medium before exposure and after development can be heated by only one heating means arranged in a common transport path with the development means, and can be heated both before exposure and after development. Therefore, the number of heating units to be installed is reduced, the configuration of the image forming apparatus is extremely simplified, and there is an effect that the manufacturing cost can be reduced.

The invention described in claim 2 is the same as that in claim 1.
In the image forming apparatus according to the above, from the heating means,
A heating amount control means is provided for controlling the amount of heating so that the amount of heat applied to the photosensitive recording medium before exposure is small and the amount of heat applied to the photosensitive recording medium after development is large. As described above, it is possible to provide an image forming apparatus capable of improving the sensitivity of a photosensitive recording medium and performing a fixing operation by simply controlling the amount of heat applied to the photosensitive recording medium from a heating unit and obtaining a high-quality image. be able to.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the heating amount control means causes the heating means on the common path to pass through a photosensitive recording medium. In this case, the transport speed of the transport unit is set to a high speed during heating before exposure by the exposure unit, and to a low speed during heating after development by the developing unit.

Accordingly, even if the heating value of the heating means itself is kept constant, the photosensitive photosensitive medium can be controlled simply by changing the moving speed (conveying speed) of the photosensitive recording medium passing therethrough to a high or low level. This has a remarkable effect that the change in the amount of heat that can be given per unit area of the recording medium can be controlled with high accuracy. The invention described in claim 4 is the first invention.
4. The image forming apparatus according to claim 3, wherein the heating unit includes a film heater having a positive temperature coefficient.

As described above, in the case of a film heater having a positive temperature coefficient, the control for keeping the heating means at a constant temperature becomes extremely simple, and the amount of heat applied to the photosensitive recording medium does not become uneven. This makes it possible to easily obtain the image of (1). Further, as in the invention according to claim 5 or 6, the heating means is constituted by dispersing conductive particles such as carbon black in an insulating synthetic resin film, or an insulating synthetic resin film. Any one of those having a heating element having a positive temperature coefficient attached to one side thereof may be formed, and the intermediate portion of the film may be bent so as to project, and fixed to the support substrate at both ends. Is what is being done.

Accordingly, by using such a film heater, heat can be applied to the photosensitive recording medium by a simple operation of sliding the middle curved projecting portion of the film heater on the surface of the photosensitive recording medium. Therefore, there is no need to rotationally drive the heating unit itself as in the conventional heating roller, and there is an effect that the driving unit is omitted and the configuration of the image forming apparatus is extremely simplified.

[Brief description of the drawings]

FIG. 1 is a configuration sectional view of a first embodiment of a photosensitive pressure-sensitive printer for processing microcapsule paper.

FIG. 2 is a bottom view of the photosensitive pressure-sensitive printer according to the first embodiment.

FIG. 3 is a graph showing a relationship between the temperature of a photosensitive recording medium and sensitivity.

FIG. 4 is a partially cutaway perspective view of a film heater as a heating unit.

FIG. 5 is a diagram showing a temperature of a film heater having a positive temperature coefficient and a change rate (based on 20 ° C.) of electric resistance.

FIG. 6 is a diagram illustrating a change in a heating temperature of a film heater.

FIG. 7 is a cross-sectional view of the microcapsule paper.

FIG. 8 is a plan view of the microcapsule paper.

9A is a schematic cross-sectional view of an exposure head, and FIG.
FIG. 4 is an enlarged sectional view of a main part of a concave portion.

FIG. 10 is an enlarged bottom view of the exposure head.

FIG. 11 is a graph showing a moving speed of a carriage.

FIG. 12 is a timing chart of exposure.

FIG. 13 is a graph showing a comparison between applied exposure energy and optical density of cyan color by single exposure and multiple division exposure.

FIG. 14 is a schematic sectional view of a conventional exposure unit.

FIG. 15 is a block diagram illustrating an electrical configuration of the photosensitive pressure-sensitive printer.

FIG. 16 is a configuration diagram of a developing device for pressure-developing microcapsule paper in the first embodiment.

FIG. 17 is a sectional view illustrating a configuration of a second embodiment of the photosensitive pressure-sensitive printer.

FIG. 18 is a plan sectional view of the configuration of a second embodiment of the photosensitive pressure-sensitive printer.

FIG. 19 is a schematic sectional view showing another embodiment of the exposure head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 4 Concave part 7a, 7b, 7c Red LED 8a, 8b, 8c as a light emitting element Green LED 9a, 9b, 9c as a light emitting element Blue LED as a light emitting element 10 Electrical connection 12 Pinhole 13 Mask (selection supply means 20) Exposure head 32 Microcapsule 37 Microcapsule paper as photosensitive recording medium 45 Developing device 47 Base 64 Film heater 80 Image forming apparatus

Claims (6)

[Claims] 1. A photosensitive recording medium which carries a microcapsule containing a photosensitive component and a colorant whose intensity changes with respect to light of a predetermined wavelength, and forms a latent image of image information upon exposure, and the photosensitive recording medium Exposure means for exposing the photosensitive recording medium, and developing means for applying pressure to the exposed photosensitive recording medium to break the weak microcapsules, and to make the latent image visible by the color material flowing out of the broken microcapsules. An image forming apparatus comprising: a conveyance path from a paper supply unit of the photosensitive recording medium to the exposure unit; and a discharge path from the development unit to a paper discharge unit, at least a part of which is a common path. Transporting the photosensitive recording medium from the paper feeding unit to the exposure unit and the developing unit through the common path, and transporting the exposed and developed photosensitive recording medium to the paper discharging unit through the common path. Feeding means, and heating means provided on the common path, for heating the photosensitive recording medium before exposure by the exposure means, and for heating again after development by the development means. Image forming apparatus. 2. A heating amount control means for controlling the heating amount from the heating means so that the amount of heat applied to the photosensitive recording medium before exposure is small and the amount of heat applied to the photosensitive recording medium after development is increased. The image forming apparatus according to claim 1, further comprising: 3. The heating amount control means sets the transport speed of the transport means when the heating means on the common path passes through the photosensitive recording medium, to a high speed during heating before exposure by the exposure means, 3. The image forming apparatus according to claim 2, wherein a low speed is set during heating after the development by the developing unit. 4. The image forming apparatus according to claim 1, wherein the heating unit is a film heater having a positive temperature coefficient. 5. The heating means is formed by dispersing conductive particles such as carbon black in an insulating synthetic resin film. The heating means is bent so that an intermediate portion protrudes, and is provided on both ends of the supporting substrate. The image forming apparatus according to claim 1, wherein the image forming apparatus is fixed. 6. The heating means has a heating element having a positive temperature coefficient attached to one surface of an insulating synthetic resin film, and is bent so that an intermediate portion protrudes. The image forming apparatus according to claim 1, wherein the image forming apparatus is fixed to a support substrate.