JPH11255388A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely eliminate a curl by introducing a photosensitive and pressure sensitive recording medium after pressure development in a pressing part between a correction guide formed like a convex in the transport direction and an endless belt to which the convex of the correction guide is pressed from the outside extending over a designated length in such a manner that the inside of a curl is on the endless belt side. SOLUTION: When power is supplied to a printer, a driving circuit of a heater 31 is operated to keep the surface of a correction guide 30 at a designated temperature. When the starting end of a photosensitive and pressure sensitive recording medium 1 subjected to the exposure process and pressure development passes through a paper position sensor, an endless belt 32 is rotated through a detection signal, CPU and a correction driving motor. The photosensitive pressure sensitive recording medium 1 is sent to a space up to the correction guide 30 with the leading edge and the trailing edge curled upward in such a manner that the curl inside is on the endless belt 32 side, and the sheet is curled in the reverse direction taking the correction guide as a guide to be sent to the curl correcting means 33. With the whole of the photosensitive pressure sensitive recording paper 1 pressed to the correction guide 30, the drive of the endless belt 32 is stopped to perform heat fixing and curl correction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method in which a latent image of image information is formed on the surface of a photosensitive and pressure-sensitive recording medium by exposure to image forming light corresponding to the image information, and the latent image is developed by pressure development. The present invention relates to a forming apparatus, and more particularly, to a structure of a means for correcting a curl of a photosensitive pressure-sensitive recording medium supplied in a roll form after a pressure development process.

[0002]

2. Description of the Related Art For example, U.S. Pat. Nos. 4,440,846 and 4,399,209 disclose that a photosensitive layer having microcapsules containing a photosensitive substance in an internal phase is exposed to a uniform burst force after being exposed to radiation corresponding to image information. An imaging system has been disclosed which causes the microcapsules to rupture, thereby releasing the internal phase material in an imagewise manner.
In this system, exposure changes the mechanical strength of the microcapsules to form an exposure latent image, and capsules with weak mechanical strength (capsules that have not cured or softened) are destroyed by applying pressure. It is known that a color-generating substance (color-forming agent) as a color material flows out and reacts with a developing substance to form a color image, thereby performing development.

[0003] A photosensitive and pressure-sensitive image-forming layer coated by mixing the microcapsules and a developing material on a first sheet-like support through which light passes, and a second sheet covering the image-forming layer. In a photosensitive pressure-sensitive recording medium formed by laminating a sheet-like support, an image is obtained as it is on the exposed sheet-like support, and handling is easy. This type of photosensitive pressure-sensitive recording medium is generally rolled in a light-shielding cassette so that it is not unnecessarily irradiated with light before data of a predetermined image is exposed, and the handling is simplified. The cassette is mounted on the image forming apparatus and the photosensitive and pressure-sensitive recording medium inside is drawn out.

Accordingly, since the drawn photosensitive pressure-sensitive recording medium has a curl (curl habit), as a curl correcting means in a conventional image forming apparatus, for example, Japanese Patent Publication No. 57-34180, Kaihei 5-330711
In these publications, a curl correction of a recording medium is performed by passing a roller or a guide plate having a convex curved portion while applying tension thereto.

[0005]

However, since the photosensitive recording medium is made of a sheet-like support such as a PET film sandwiching a coloring material on both sides, it is difficult to remove the curl once the curl is formed. In particular, a photosensitive pressure-sensitive recording medium wound in a roll form has a smaller curl amount as the roll diameter is larger, but also has a larger curl amount as the roll diameter is smaller, and includes a roller and a convex curved portion to tension the guide plate. However, there is a problem that the curl cannot be sufficiently removed even if the sheet is passed through the cover.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has as its object to provide an image forming apparatus having a curl correcting means capable of reliably removing curl of a photosensitive and pressure-sensitive recording medium. I have.

[0007]

In order to achieve this object, the invention according to claim 1 of the present invention comprises an exposure means for exposing a photosensitive pressure-sensitive recording medium to form a latent image, and In the image forming apparatus provided with a pressure developing unit that makes the surface visible, a correction guide formed in a convex curved shape in the conveyance direction on the downstream side of the conveyance from the pressure development unit, and a convexity of the correction guide Arranged a curl straightening means having an endless belt that presses the curved surface portion from the outside over a predetermined length,
The endless belt is driven so that the photosensitive pressure-sensitive recording medium after pressure development is introduced into the pressure contact portion between the straightening guide and the endless belt so that the curl inside thereof is on the endless belt side. is there.

[0008] The invention described in claim 2 is the first invention.
The image forming apparatus according to claim 1, further comprising control means for controlling driving of the endless belt driving means so that the photosensitive pressure-sensitive recording medium is stopped after being stopped for a predetermined time in the pressure contact portion. According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the correction guide includes a heat source.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of a main part of an image forming apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view of a photosensitive pressure-sensitive recording medium, and FIG. 3 is a side view of a main part of a curl correcting unit. In FIG. 1, a photosensitive pressure-sensitive printer 1
A light-shielding cassette 11 is detachably attached to the rear part of the case body 10a of the light-shielding cassette 11, and inside the light-shielding cassette 11,
A photosensitive pressure-sensitive recording medium 1 wound in an unexposed roll form is mounted. The winding state at this time is such that the light-transmissive sheet-shaped support 2 of the photosensitive pressure-sensitive recording medium 1 described later is positioned inside the winding.

In a state where the light-shielding cassette 11 is set at a predetermined position of the photosensitive pressure-sensitive printer 10, a required amount of the photosensitive pressure-sensitive recording medium 1 is pulled out from the cassette 11 by a pair of paper feed rollers 12, and is used as cutting means. Is cut into a predetermined length by the cutter 13. Next, the photosensitive pressure-sensitive recording medium 1 having a predetermined length is sent in the direction of the exposure position by a conveying means 14 such as an endless belt.

A paper position detection sensor (not shown) for detecting the start end and the end of the photosensitive pressure-sensitive recording medium 1 is provided at a predetermined position downstream of the conveying means 14. The control means sets the photosensitive and pressure-sensitive recording medium 1 at a predetermined exposure position on the transport means 14. Although the configuration of the exposure unit 15 on the exposure position is not shown, for example, a light source box containing a lamp and a condenser lens, a filter plate disposed in front of the light source box and on one side of the conveyance unit, and A filter plate in which a liquid crystal plate disposed in front is fitted, and a filter of three colors of red, blue and green and a filter for color tone correction are fitted, is rotated by a motor. A mirror or prism that bends the optical path and an imaging lens are arranged in front of the filter plate to irradiate the exposure image on the photosensitive pressure-sensitive recording medium 1 at the exposure position.

A pressure developing means 20 comprising a pair of upper and lower pressure rollers 21, 22 and the like is arranged downstream of the transport means 14. Due to the operation of the pressure developing means 20, the surface of the exposed photosensitive pressure-sensitive recording medium 1 is elastically pressed, and the microcapsules are broken by applying pressure to the microcapsules, causing the inclusions (colorless dye precursor) to flow out. This causes a color development reaction with a color developer to visualize a color image.

The pressure-sensitive and pressure-sensitive recording medium 1 after the pressure development is passed through a portion of a curl correcting means 23 which will be described later in detail, where curl correction and heat fixing are performed. Through the case body 10a. Next, the structure of the photosensitive pressure-sensitive recording medium 1 will be described with reference to FIG.

On one side of the light-transmissive sheet-like support 2 located on the upper side in FIG. 2, a component that forms a color upon contact with a co-reactant as a coloring material (a dye precursor, hereinafter referred to as a chromogen) ) And a component (photo-curable resin) whose mechanical strength changes (photo-curing) upon exposure to light of a predetermined wavelength, and a dye precursor ( And a co-reactant (developing agent) 5 reacting with the chromogen), and a light-sensitive and pressure-sensitive mixed coating layer 3 is laminated thereon, and an adhesive is further provided on the mixed coating layer 3. A sheet-like support 8 is laminated via the layer 7, and a writable layer 9 is provided on the outer surface of the sheet-like support 8.

As the light-transmitting sheet-like support 2, a resin film such as polyethylene terephthalate (PET), polyethylene naphthalate, or polyphenylene sulfide, which is colorless and transparent and has appropriate rigidity and tensile strength, is preferably used. Further, the sheet-like support 8 is
It is preferable to use an opaque material (opaque material) so that the image can be observed well when the image output is placed on a dark background. In addition, a resin film such as PET, PEN, or PPS containing a white pigment such as titanium oxide or zinc oxide can be used. Also, on transparent or opaque films,
It may be white by providing a coating layer containing a white pigment such as titanium oxide or zinc oxide.

In the embodiment, the thickness of the upper light-transmitting sheet support 2 is set to about 75 μm, and the thickness of the lower sheet-like support 8
Is set to about 50 μm. The microcapsules 4 include three types of different microcapsules, and each of the different types of microcapsules 4
Include a colorless dye precursor for producing one of yellow, magenta, and cyan, a photocurable resin that is cured by being exposed to light of each of the three primary colors of light, and a polymerization initiation. Agents are included.

For this reason, for example, blue light (about 470 nm)
Is exposed to the photosensitive pressure-sensitive recording medium 1,
Microcapsules 4 containing yellow-only dye precursor 4
Of the photocurable resin is photosensitively cured. When pressure is applied to the photosensitive pressure-sensitive recording medium 1, the photosensitive-cured microcapsules 4
(In this case, yellow) is not destroyed. The microcapsules 4 (magenta and cyan in this case) that have not been photosensitive-cured are destroyed, and the magenta and cyan dye precursors flow out of the microcapsules 4 and react with the developer to form a color. It turns blue. This blue color is observed through the transparent sheet-like support 2.

When green light (light having a wavelength of about 525 nm) is exposed to the photosensitive pressure-sensitive recording medium 1, the photocurable resin of the microcapsules 4 containing the magenta-only dye precursor hardens. When pressure is applied to the photosensitive and pressure-sensitive recording medium 1, the yellow and cyan microcapsules 4 are destroyed by pressure development, and the yellow and cyan dye precursors and the developer are colored to form green by mixing. Become. This green color is observed through the transparent sheet-like support 2.

Further, when red light (light having a wavelength of about 650 nm) is exposed to the photosensitive pressure-sensitive recording medium 1, the photocurable resin of the microcapsules 4 containing the dye precursor of only cyan is photosensitive cured. When a pressure is applied to the photosensitive and pressure-sensitive recording medium 1, the yellow and magenta microcapsules 4 are destroyed by pressure development, and the yellow and magenta dye precursors react with the developer to develop colors and mix to red. Becomes This red color is observed through the transparent sheet-like support 2.

When all the microcapsules 4 are photosensitive-cured by exposure, they are not destroyed even if pressure-developed, so that no color development occurs and the sheet-like sheet 2 is passed through the light-transmissive sheet-like support 2. The surface of the support 8 is in a visible state. Therefore, the white color on the surface of the sheet-like support 8 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-transmissive sheet-like support 2 in the photosensitive and pressure-sensitive recording medium 1 is referred to as a coloring side surface.

The microcapsules 4 include chromogens of triphenylmethane-based and spiropyran-based dyes, photocurable resins of acryloyl group-containing compounds such as trimethylolpropane triacrylate, benzophenone,
A photopolymerization initiator such as benzoylalkyl ether,
Known materials such as those encapsulated in polymer walls such as gelatin, polyamide, polyvinyl alcohol and polyisocyanate resin can be used.

The co-reactant 5 may be related to the composition of the chromogen in the microcapsule 4 or the like, but may be an acidic substance, for example, an inorganic oxide such as acid clay, kaolin, acidic zinc, or titanium oxide. Phenol novolak resin, or a known developer such as an organic acid can be used. For this mixture of microcapsules 4 and co-reactant 5,
In addition, binders, fillers, viscosity modifiers, etc. are added,
The mixed coating layer 3 is formed on the light-transmissive sheet-like support 2 by a coating roller, a spray, a doctor knife, or the like.

Next, the curl correcting means 23 will be described with reference to FIG.
This will be described with reference to FIG. The curl correcting means 23 includes:
A straightening guide 30 having a convex curved surface portion along the transport direction of the photosensitive and pressure-sensitive recording medium 1 (the direction of arrow A in FIG. 3), and a heater 31 as a heat source attached to the back side of the straightening guide 30
And an endless belt 32 for pressing the convex curved surface of the correction guide 30 (a convex semi-circular portion facing right in FIG. 3) from the outside. The straightening guide 30 is formed by bending a metal plate having excellent thermal conductivity, such as aluminum, with a predetermined radius, and the heater 31 has a conductive heating element printed on a thin film film of polyimide or the like inside. The film itself is configured to generate heat by performing current driving, and is adhered to the back surface (inner diameter side) of the correction guide 30.

The endless belt 32 is formed by applying heat-resistant rubber or the like to the surface of a heat-resistant reinforcing fiber, for example, an aromatic polyamide fiber, and is provided at four positions at the upper and lower positions of the straightening guide 30 and at a position separated from each other. It is wound around a pulley 33, and one of the pulleys 33 is driven by a straightening drive motor 34,
The endless belt 32 rotates downward (arrow B direction) in FIG. A paper position sensor 35 such as a photo sensor is arranged on the start end side of the straightening guide 30 to detect the start end of the photosensitive pressure-sensitive recording medium 1 conveyed to the curl correcting means 23,
The drive start timing of the endless belt 32 is controlled by a controller 50 described later. In addition, a temperature sensor 36 such as a thermistor is disposed at an appropriate position of the correction guide 30,
The energization control of the heater 31 is performed so that the surface temperature of the correction guide 30 is detected and maintained at a predetermined constant temperature.

The endless belt 32 presses the convex curved surface of the correction guide 30 from the outside over a predetermined angle at which the entire length of the photosensitive pressure-sensitive recording medium 1 can be pressed against the correction guide 30. The endless belt 32 is driven until the entirety of the photosensitive pressure-sensitive recording medium 1 is taken into the curl correcting means 23, then stopped for a predetermined time, and driven again when the curl correcting means 23 sends the medium.

An electronic controller 50 such as a microcomputer shown as a functional block diagram in FIG. 6 controls the printer as a whole, such as transporting the photosensitive pressure-sensitive recording medium 1, exposure and pressure development, and also controls the drive timing of the curl correcting means 23. A ROM 51 storing a control program and the like; a RAM 53 storing various data such as a value detected by the paper position sensor 35;
An interface 54 and the like are provided. The interface 54 includes a paper position sensor 35 and a temperature sensor 36.
And driving means (not shown driving motor) for the sheet feeding roller pair
55, a driving circuit 56 for an operating actuator of the cutter 13, a driving circuit 57 for the exposure unit 15, a driving circuit 58 for the conveying unit 14, a driving circuit 59 for the pressure developing unit 20, A drive circuit 60 for the correction drive motor 34 in the curl correction means 23, a drive circuit 61 for the ejection actuator 37, a drive circuit 62 for the heater 31, and the like are connected.

Next, a series of operations in the curl correcting means 23 will be described with reference to FIGS. 4 (a), 4 (b) and 5. FIG. In this case, when the power of the printer 10 is turned on, the drive circuit 62 of the heater 31 operates, and the surface of the correction guide 30 is maintained at a predetermined temperature. When the starting end 1a of the photosensitive and pressure-sensitive recording medium 1 subjected to the exposure processing and pressure development has passed through the paper position sensor 35, a detection signal is output.
The correction drive motor 34 is driven by a command from the PU 51, and the endless belt 32 rotates. At this time, as shown in FIG. 4A, the exposed and light-sensitive pressure-sensitive recording medium 1 is such that the leading end and the rear end of the light-sensitive pressure-sensitive recording medium 1 are curled upward, and the inside of the curl comes to the endless belt 52 side. So straightening guide 30
And the endless belt 32, and is sequentially fed into the curl correcting means 32 while being curled in the opposite direction by the endless belt 32 with the correction guide 30 as a guide.

Then, as shown in FIG. 4B, the drive of the endless belt 32 is stopped for a predetermined time while the entire photosensitive pressure-sensitive recording medium 1 is pressed against the correction guide 30, and the photosensitive pressure-sensitive recording is performed during that time. The heat fixing and the curl correction of the medium 1 are performed. The time counting timer is based on a clock built in the controller 50. After a lapse of a predetermined time, the correction driving motor 34 is restarted by a command from the CPU 51, and the endless belt 32 is driven again, as shown in FIG.
Is discharged out of the curl correcting means 23 and sent to a discharge tray 25 in a substantially horizontal state by a driving roller 26. afterwards,
By driving the ejection actuator 37, the tip of the ejection tray 25 is turned downward (see a two-dot chain line in FIG. 1),
The photosensitive pressure-sensitive recording medium 1 is inserted into the outlet 10b of the main body case 10a.
It emits.

In the above-described embodiment, the case has been described in which the curl habit formed when the photosensitive pressure-sensitive recording medium 1 wound in a roll shape is pulled out into the light-shielding cassette 11 is corrected.
In the case of the photosensitive pressure-sensitive recording medium 1 which has been cut to a predetermined size in advance, it is needless to say that the curl habit formed by the exposure processing and the pressure development processing can be corrected by the curl correcting means 23 of the present invention. Further, in the above-described embodiment, the heater 31 is provided on the inner diameter side of the straightening guide 30.
When the heat fixing is unnecessary, or when the curl is little, even if the heater is turned off, the correction guide 30
The curl can be corrected only by holding the photosensitive pressure-sensitive recording medium 1 between the endless belt 32 and the endless belt 32 for a certain period of time. Also, a configuration may be adopted in which a long photosensitive pressure-sensitive recording medium that has not been cut by the cutter 13 is fed to the curl correcting means 23, and the endless belt 32 is continuously rotated at a predetermined speed to remove curls continuously. good.

The thickness of the light-transmissive sheet-like support 2 and the thickness of the sheet-like support 8 among the sheet-like supports sandwiching the photosensitive and pressure-sensitive image forming layer 3 in the photosensitive and pressure-sensitive recording medium 1 are different. Then, the thin portion is easy to stretch, and the thin side is outside the curl. Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments at all, and it is needless to say that the present invention can be carried out in various modes without departing from the gist of the present invention. It is.

[0031]

As described above in detail, according to the first aspect of the present invention, an exposure means for exposing a photosensitive pressure-sensitive recording medium to form a latent image, and the latent image is made visible. In the image forming apparatus provided with the pressure developing means as described above, on the downstream side of the pressure developing means in the conveyance direction, a correction guide formed in a convex curve shape in the conveyance direction, and a convex curved surface portion of the correction guide is outward. A curl straightening means having an endless belt which is in pressure contact with the endless belt over a predetermined length is arranged, and the photosensitive pressure-sensitive recording medium after pressure development is placed in the pressure contact portion between the straightening guide and the endless belt, and the curl inside thereof is the endless belt The endless belt is driven so as to be introduced to the side.

Accordingly, the photosensitive pressure-sensitive recording medium 1 sandwiched between the pressure contact portions of the correction guide and the endless belt receives pressure in the direction opposite to the curl habit, whereby the curl habit can be corrected. Since the photosensitive pressure-sensitive recording medium can be fed into and out of the curl correcting means by driving the endless belt, the photosensitive pressure-sensitive recording medium is not limited to a continuous one, and is curled even if it is a cut sheet. It has the effect that the habit can be corrected.

[0033] The invention described in claim 2 is the same as in claim 1.
The image forming apparatus according to the above, further comprising control means for controlling driving of the endless belt so that the photosensitive pressure-sensitive recording medium is stopped after stopping the photosensitive pressure-sensitive recording medium for a predetermined time in the pressure contact portion. The stop time may be set according to the strength of the habit, and in addition to the effect according to the first aspect of the present invention, the effect that the curl habit can be reliably corrected is exhibited.

According to the third aspect of the present invention, since the correction guide is provided with a heat source, in addition to the effects of the first or second aspect, the photosensitive pressure-sensitive recording medium is provided. This also has the effect that the curl can be removed while performing heat fixing.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a photosensitive pressure-sensitive printer showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a photosensitive pressure-sensitive recording medium.

FIG. 3 is an enlarged side view of the curl correcting means according to the embodiment of the present invention.

FIGS. 4A and 4B are side views showing the operation of the curl straightener according to the embodiment of the present invention, in which FIG. 4A shows a state in which the photosensitive pressure-sensitive recording medium is started to be fed, and FIG. This shows a state in which the photosensitive pressure-sensitive recording medium is being pressed.

FIG. 5 is a side view showing a release state of the photosensitive pressure-sensitive recording medium after the curl correction.

FIG. 6 is a functional block diagram of a controller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photosensitive pressure-sensitive recording medium 15 Exposure means 21, 22 Pressure roller 23 Curl correction means 30 Correction guide 31 Heater 32 Endless belt

Claims (3)

[Claims] 1. An image forming apparatus comprising: an exposure unit configured to expose a photosensitive pressure-sensitive recording medium to form a latent image; and a pressure development unit configured to visualize the latent image. On the downstream side of the conveyance, a straightening guide formed in a convex curved shape in the conveying direction, and a curl straightening means having an endless belt that presses the convex curved surface portion of the straightening guide over a predetermined length from the outside are arranged, The endless belt is driven so that the photosensitive pressure-sensitive recording medium after pressure development is introduced into the pressure contact portion between the correction guide and the endless belt so that the curl inside thereof is on the endless belt side. Image forming apparatus. 2. The apparatus according to claim 1, further comprising control means for controlling driving of said endless belt driving means so as to discharge the photosensitive pressure-sensitive recording medium after stopping the photosensitive pressure-sensitive recording medium for a predetermined time in the pressure contact portion. The image forming apparatus as described in the above. 3. The image forming apparatus according to claim 1, wherein the correction guide includes a heat source.