JP2572467B2 - Full-color image forming device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Field of the Invention The present invention relates to image formation using a photosensitive sheet in which a plurality of types of microcapsules each having sensitivity to light of different wavelengths are uniformly dispersed and coated on the same base sheet. The present invention relates to an improvement in an image forming apparatus for performing the above.

(B) Prior Art As a method for forming a full-color image, there is a method using a photosensitive sheet coated with several kinds, generally three kinds of microcapsules. The three types of microcapsules are:
A microcapsule (Y capsule) enclosing a photo-curing material that cures upon exposure to blue wavelength light and a dye that develops yellow, a photo-curing material that cures upon exposure to green wavelength light, and a dye that develops magenta And a microcapsule (C capsule) for enclosing a photocurable material that is cured by being exposed to red wavelength light and a dye that develops cyan. When the photosensitive sheet on which the three types of microcapsules are uniformly dispersed and applied is exposed by, for example, reflected light of a full-color photograph, each microcapsule is partially cured by light having a wavelength having sensitivity. Thereafter, when the photosensitive sheet is pressurized, only the uncured microcapsules are destroyed and an image is formed by the dye that flows out.

When a full-color image is formed, the image may have a specific color depending on the user's preference. Conventionally, in an image forming apparatus using the photosensitive sheet, a filter is arranged in an optical path of exposure light for exposing the photosensitive sheet to partially cut off light having an arbitrary wavelength to give a specific color to an image. Was.

(C) Problems to be Solved by the Invention However, when a filter is inserted in the optical path of the exposure light as in the related art, there has been a problem that not only the wavelength light to be cut, but also the overall light quantity is reduced. The overall sensitivity of the photosensitive sheet is relatively low, and a decrease in the amount of light is not preferable.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus capable of giving a desired color to a formed image without using a filter.

(D) Means for Solving the Problems The present invention illuminates a photosensitive sheet coated with a plurality of types of microcapsules, each having sensitivity to light of a different wavelength, by irradiating mixed light of each wavelength to the photosensitive sheet. In the image forming apparatus for exposing, a heating unit for heating the photosensitive sheet at the time of exposing an image, a unit for inputting a color of an arbitrary image, and controlling the heating unit according to the color input to the input unit. And temperature control means for controlling the heating temperature.

(E) Function Generally, a resin that polymerizes at a specific wavelength is used as a photosensitive material (photo-curing material) of the microcapsule. This polymerization reaction state is the sensitivity of the microcapsule. The state of the polymerization reaction of such a resin is also affected by heat, and the manner in which the resin is affected by heat varies depending on the type. Therefore, for example, while the sensitivity of one microcapsule increases with an increase in temperature, the sensitivity of another microcapsule may decrease with the same increase in temperature.

The present invention utilizes such characteristics of the photosensitive sheet,
The formed image is adjusted to any color. That is, the plurality of types of microcapsules applied on the photosensitive sheet have different temperature characteristics, and are hardened or hardened by increasing or decreasing the temperature. In the present invention, the temperature of the photosensitive sheet at the time of exposure is set in accordance with the input arbitrary color tone, whereby the curing state of each microcapsule is changed, and the amount of each dye (the density of each color) flowing out is adjusted.

(F) Embodiment FIG. 4 is a schematic front view of a copying machine according to an embodiment of the present invention.

An original table 1 made of a transparent hard glass body is provided on the upper surface of the copying machine main body. An optical system 2 including a light source, a mirror, and a lens is provided below the original table 1, scans the original 1a placed on the original table 1, and guides the reflected light to an exposure unit described later. On the left side in the copying machine main body, a media cartridge 3 is provided detachably with respect to the copying machine main body. The media cartridge 3 includes a supply shaft 3a and a take-up shaft.
An unused photosensitive sheet 4 is wound around the supply shaft 3a. The supply shaft 3a is stored in the storage chamber 31 together with the wound photosensitive sheet 4 so as to be shielded from external light and external pressure. One end of the photosensitive sheet 4 is pulled out of the storage chamber 31, and is wound around the winding shaft 3b via the exposure section P1 and the pressure development section P2 in the copying machine main body.

An exposure table 5 is provided in the exposure section P1, and a panel heater 51 is disposed on a lower surface thereof. The photosensitive sheet 4 is fed on the exposure table 5 in the direction of arrow A. During this time, the exposure table 5 is heated by a panel heater 51 disposed on the lower surface. S1 is a sensor for detecting the temperature of the panel heater 51 (photosensitive sheet 4). The reflected light of the original 1a is guided to the exposure portion P1 by the optical system 2 described above. Therefore, the photosensitive sheet 4 is exposed while being heated by the panel heater 51.
By this exposure, a part of the microcapsules applied on the photosensitive sheet 4 is hardened.

The pressure developing section P2 is constituted by a pair of pressure rollers 6. The pressure roller 6 can be pressurized / released by a pressurizing mechanism including a spring and an eccentric cam (not shown), and is pressurized only during the pressure development process. 6a and 6b are backup rollers that press the upper pressure roller in the radial direction so that the pressure roller 6 is uniformly pressed. On the other hand, a paper cassette 7 is provided on the right side of the copying machine main body, and an image receiving sheet 71 is stored therein. At the time of image formation, an image receiving sheet is fed from one of the paper cassettes, and is superimposed on the photosensitive sheet 4 and pressed by the pressure developing unit P2.
As a result, the uncured microcapsules on the photosensitive sheet 4 are destroyed, and the encapsulated dye is transferred to the image receiving sheet.
It flows out onto 71 to form an image. The image receiving sheet on which the image has been formed in this manner is subjected to a glossing process by the image glossing device 8, and then is discharged to a discharge tray 9 on the left side of the copying machine main body. The photosensitive sheet whose microcapsules have been destroyed is wound up on the winding shaft 3b.

FIG. 3 is a block diagram of a control unit of the copying machine. The copying process is controlled by the microcomputer 21. An operation unit is provided on an upper surface of the copying machine main body, and input keys and a display panel are provided. A desired color tone, copy magnification, and the like are input from the operation unit 22. The microcomputer 21 operates the optical system, the photosensitive sheet conveying system, and the like in response to the input, and also controls the heater driving system 23 to use a panel heater.
Outputs 51 control temperatures. Based on the control temperature, the heater drive system 23 maintains the panel heater 51 at the control temperature while checking the detection state of the temperature sensor S1. The operation unit 22 is
This is a means for inputting the color of the image of the present invention, the panel heater 51 is also a heating means, and the temperature sensor S
1. The heater drive system 23 and the microcomputer 21 are also temperature control means.

Next, the relationship between the temperature of the panel heater 51 and the color of the formed image will be described.

As described above, the photosensitive sheet 4 is coated with three types of microcapsules, a Y capsule, an M capsule, and a C capsule. Different types of photocurable materials are encapsulated in these microcapsules, and some of them are sensitive to temperature and others are hardly affected by temperature. For example, as shown in Fig. 2, a C capsule that is sensitive to red light close to infrared rays has low sensitivity (about 30 ° C) with 35 ° C as a reference, and the capsule becomes hard to cure at high temperatures (about 40 ° C). , The sensitivity is improved and the capsule is easily cured. On the other hand, the Y capsule and the M capsule show almost constant sensitivity regardless of the temperature. That is, as shown, the sensitivity is almost the same as when the C capsule is at 35 ° C. When such a photosensitive sheet is used and exposure processing is performed, for example, by setting the sheet temperature to 35 ° C., as shown in FIG. 1A, all three types of microcapsules exhibit the same sensitivity and are formed. In the image, the color of the document is reproduced almost exactly. However, when the temperature of the photosensitive sheet is set at 40 ° C. as shown in FIG. 4B, the sensitivity of the C capsule is increased as compared with other capsules, and the C capsule is less likely to be destroyed, so that the entire image is reddish. Color. When the temperature of the photosensitive sheet is set at 30 ° C. as shown in FIG. 3C, the sensitivity of the C capsule is lowered and the capsule is easily broken, and the image becomes bluish as a whole.

The microcomputer 21 of the main body of the copying machine stores such a relationship between the temperature of the photosensitive sheet and the color change state. Since the information on the temperature and the color varies depending on the type of the photosensitive sheet and the production lot, the information is input each time a new photosensitive sheet is mounted. As a method for inputting information, there is a method of marking information on a photosensitive sheet in advance, reading the information with an optical sensor of the copying machine main body, or inputting the information with a dip switch or the like.

When an arbitrary color is input from the input unit based on the information on the relationship between temperature and color stored in the microcomputer 21, the control temperature of the panel heater 51 is set accordingly. For example, in the case of a copying machine using the above-described photosensitive sheet, when a request to make a bluish image is input from an operation unit on the copying machine body, the microcomputer 21 controls the temperature of the panel heater 51 to approximately 30 ° C. Then, as described above, the entire image becomes bluish, and the image according to the user's desire can be obtained.

The example of the temperature control of the panel heater of this embodiment is merely an example, and the temperature of the panel heater is controlled at room temperature to 100 ° C., preferably about 20 to 50 ° C. according to the type of the photosensitive sheet (the microcapsules to be coated). Is done.

(G) Effects of the Invention As described above, according to the present invention, the temperature of the photosensitive sheet is controlled in accordance with the input arbitrary color tone, and the color tone of an image formed thereby can be adjusted. Therefore, unlike the related art, it is not necessary to insert a filter in the optical path of the exposure light, and the problem of a decrease in light amount can be solved.

[Brief description of the drawings]

1 (A) to 1 (C) and FIG. 2 show the relationship between the sensitivity of the photosensitive sheet and the temperature, FIG. 3 is a block diagram of a control unit of a copying machine using the photosensitive sheet, and FIG. The figure is a schematic front view of the copying machine. 4 photosensitive sheet, 5 exposure table, 51 panel heater, S1 temperature sensor.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Fumie Nishino 22-22 Nagaikecho, Abeno-ku, Osaka-shi, Osaka Inside Sharp Corporation (56) References JP-A-1-1822853 (JP, A) JP-A-63 −262639 (JP, A)

Claims (1)

(57) [Claims] 1. An image forming apparatus, wherein a photosensitive sheet coated with a plurality of types of microcapsules each having sensitivity to light of a different wavelength is irradiated with mixed light of each wavelength to expose the photosensitive sheet. Heating means for heating the sheet at the time of exposing the image, means for inputting an arbitrary color of the image, temperature control means for controlling the heating means, and controlling the heating temperature according to the color inputted to the input means. A full-color image forming apparatus, comprising: